Category Archives: Feature

World Champion Trials School in Tulsa, Oklahoma

Photo Credit: Scott Williams, USA.

World Champion and Scottish Six Days Trial winner Bernie Schreiber conducted his ZeroBS two-day Masterclass on May 13 & 14 in Tulsa Oklahoma at Tulsa Mountain Trials. Schreiber, being the most successful Trials rider ever from the USA, shared his experiences with participants attending from 8 nearby States. The event was hosted by one of the oldest clubs in America, (N.E.O.T.T.) North Eastern Oklahoma Trials Team, founded in 1969 by Mike McCabe, who became the first American to compete at the Scottish Six Days Trial in 1972.

Schreiber first discussed the event with his long-time friend, Kirk Mayfield of Oklahoma who competed in the 1973 Scottish Six Days Trial on a Mick Andrews factory Yamaha. Mayfield and Schreiber competed together in the Turkey Creek U.S. National in 1975, an event that included many of the best riders in US history.

Schreiber treated the 30 participants to his structured format based on lessons learned in becoming a World, National, and Scottish Six Days Trial Champion, but also basic techniques from his book “Observed Trials” by Len Weed and other sports such as golf, where direct comparisons become involved. Mastering the sport, hands on riding and the all-important Mastering the mind were covered in great detail.

Schreiber said, its not just skills and hard work. Everyone at the top level has great techniques. Your mindset is what makes you the winner or the loser. That’s the only difference.

“Practice doesn’t make you perfect. Only perfect practice does.”

He continued to focus on the competition successes and practicing with purpose by design. The best way to practice is prioritize on the things you need to practice, and knowing which tasks should get top priority, then act to get maximum returns. Progressing consistently in a way that lets you maintain present skills, but also allows to move to the next level continually is a priority, while keeping yourself motivated and maintain focus so you can stay in the best possible state of mind for achieving results.

The sit-down classroom setting began first before feet on the pegs riding, by covering the most important aspect of motorcycle trials, the proper stance. Motorcycle trials has always been a very unique form of off-road riding which requires certain techniques that do not always apply to riding a “normal” dirt bike, especially when it comes to the fundamentals. Many aspects were demonstrated during what Schreiber calls “Impact Zones” throughout two full days of instruction.

Schreiber also covered what gave him an advantage over his rivals, that being the technique which he introduced and perfected, the floating front wheel turn. Also known as the “Pivot turn”, Schreiber used this to great effect in winning the World Championship and showed exactly why this technique is just as effective today.

During each day of the school, each individual student was given one on one instruction on the techniques of this challenging sport and an insight into what actually makes a World Champion, the attention to detail, leaving no stone unturned.

The Current State of Modern Trials

This article has been reproduced from the world famous trials website, todotrial in Spain. Permission given by todotrial owner, Horacio San Martin to Trials Guru.

(Main photo: Rene Opstals)

30 points to understand the decline of the sport of Trials

The sport of trial is currently not going through its best of times, but it is not something new, rather it has been declining slowly for no less than two decades. In this article we will try to analyze the causes by giving 30 points to help us understand what is happening.

We have been hearing that the sport of trials has been in crisis for 20 years or more , and although it is true that the trial situation is difficult, it is also true that depending on the places and areas the situation may seem less dramatic . And it is that there are areas and sectors in which the sport enjoys good health or trial competitions with plentiful entries.

However, these bright spots should not distract us or mislead us, the reality is that the trial market has been in decline, little by little, but inexorably, giving rise to concern.

Undoubtedly, this widespread news that shakes the motorcycle press each year does not go unnoticed, especially those in which the decision of prominent young riders, to abandon this discipline is revealed , mainly due to lack of finance. These are not just a few cases in which riders who aimed high have decided to switch to enduro in search, no longer of greater fortune, but simply to earn a minimal living without going bankrupt.

This has been happening for more than a decade, but the problem has been getting worse , since now even pilots who are among the best in the world are seen in this situation , such as the recent case of Toby Martyn , world champion. Trial2 in 2021 and British trials champion in 2021 and 2022, or his compatriot, Jack Dance , who was Trial 125 world champion in 2021. Dan Peace’s move to enduro this year does not go unnoticed either, or that of no less than one of the World Cup top, Miquel Gelabert , although the latter is a more special case due to his personal complications. There are many more cases like those of Jack Price ,Eric Miquel , or Sergio Ribau to name just a few of the most recent.

But let us not fool ourselves, trials has always been and will always be a minority sport, in which there has never been more than 15 or 20 official or semi-official riders, what happens is that as things are, now there is hardly any room for 5 or 6 professional riders and in the highest category of the TrialGP World Championship it continues to decline.

When this type of news is made public, the comments posted on social media are many and varied, logically there are opinions of all kinds, but the reality is that few get close to the real substance of the matter, and that is where we will try to achieve in this article, where we will analyze the situation in the most objective way possible.

1- The volume of trials machines sold has been stagnant for almost two decades and has dropped in the last two years. This factor is critical, since to assess the health of an activity, be it sports or of another type, the main measurement factor to take into account is the market, the volume of business it generates, is ‘sales’, the true measure. This is the base that sustains everything, and if it fails, the rest will follow.

2- The current volume of trial fans is much lower than that existing in the 70s, 80s and 90s. This factor is what determines the stagnation of the previous point, and therefore it is the most important. We can see the causes that cause it in the following points, but it is also essential to analyze what that mass of fans is like today.

3- The average age of most current trial fans is well over 40 years of age. This is because they started trial in the 70s, 80s and 90s, therefore it is a “mature age” hobby. The positive part is that in this age range their disposeable wealth allows them to renew their motorcycle regularly. This also indicates that the trial of that era had more power to create fans.

4- The young riders who entered the sport in the last 30 years, do so mostly by “inheritance”. That is, because they are children, nephews, friends of older people who practice it and who influence them to take part. They come to the sport by external influence, not by their own decision, becoming an “inbred” sport.

5- The current leisure options are endless and the culture of the “online” is significant. Being the “son of a trials rider” does not guarantee that this young man will also be a trials rider, many are not attracted to this sport and adopt other hobbies, also today there are many leisure options and the emergence of video games and other online entertainment captures the youth more effectively. This point together with the two previous ones makes the possible growth factor zero or negative.

6- The pressure of a misunderstood radical environmentalism. The current fashion of environmentalism is actually a big business, so it has gone from being something logical and recommendable to something absolutely disproportionate, radicalized and even harmful to society. The pressure exerted by environmental groups has “brainwashed” the population based on speeches that are often false, aided by politicians and the media that are not very objective, with a background of economic interests. We trial riders know that our sport is completely compatible with sustainability and respect for the environment, but our image has been badly damaged.

7- Environmental laws harm, but not globally. From the previous point derives the creation of very restrictive laws, which on many occasions simply prohibit instead of regulating, making clear the incompetence of a political class at the service of the pressures of environmental and economic power. This has undoubtedly harmed the practice of trial in many places, but its influence is not as important as it might seem, since Enduro has the same problem, and yet the volume of practitioners and motorcycle sales is enormous compared to trial . On the other hand, there are many countries without these problems, where it is clear that there are hardly any trial practitioners, but the enduro market is very broad. This indicates that this is a problem existing only at the local level.

8- Few trial practice areas in certain places. Like the previous point, this is a problem that occurs only at the local level. In those places where there are restrictive laws for the free practice of sport, it is necessary to have places where you can practice legally. In some countries it is very easy to create private areas as you only need the owner’s permission, but in other countries with more intrusive governments, creating an area can be enormously complex in terms of permits, bureaucracy and conditions, as unfortunately happens in Spain.

9- The volume of new potential clients is very low. All economic and business activity is based on attracting new customers, the advertising and promotion of brands is based on that foundation, being the basis of its growth. Currently, potential trial clients are very scarce. Where they could be most popular is among those who are already fans of off-road motorcycles and already practice other more widespread modalities, such as enduro, motocross or trials, but very few of them show interest in trials.

10- The power of attraction of current trials is much less than previously. In the previous point we have said that the volume of potential clients is very low, however we have mentioned enduro, motocross or trail practitioners as such, which are quite numerous, why this contradiction? Well, because today the number of fans of those other off road disciplines who are attracted to trial is very low, despite the undeniable advantages of mastering the trial technique to improve off road driving in general. Because? We see it in the next point.

11- The Image of elitist, static sport and only available to a select few. This is the reason why in the previous point we say that the power of attraction of the trial is much less than before. The evolution towards a more “indoor” and acrobatic trial presents a very elitist image of the sport, that is, extremely technical and difficult, which is only available to a few, distancing it from the potential public. To this are added other keys that we see below.

12- The empowerment of trials as a spectacle, causes a loss of interest as a sport. From the previous point we come to this one, Trials seems to have evolved into a show, in which it seeks to impress the public with bigger and higher obstacles. This can cause a greater attendance of the public who occasionally go to see a high-level event (World or National) with the intention of seeing a show, but at the same time it prevents them from being interested in becoming participants. Like when you go to a circus to see trapeze artists, these can cause the sale of many tickets, but not the interest in becoming a trapeze artist, because it is something extremely difficult, dangerous and elitist.

13- Indoor trials have clearly become a show, whose main objective is to sell tickets. Initially, the objective of indoor trials events was to bring the trial sport, which was conducted in the natural environment, to a larger public, in order to try to increase the number of participants of this sport, increase potential clients and thus increase machine sales. However, now, as has been said in the previous point, the objective is to increase ticket sales and it is difficult to generate interest in trial participation.

14- The Indoor has greatly influenced the natural trial or “outdoor” changing its characteristics. This influence has made outdoor trial areas much more indoor in style, with large steps, very tight turns and very little space, demanding riding techniques from Biketrials, even in regional amateur trials. It has completely changed the layout of the zones making it an even more difficult and demanding sport than it was before.

15- Passage from a sport of dynamic balance to one of static. The previous point has meant that trial has gone from having an image of a dynamic sport of overcoming moving obstacles, to an image of a much more acrobatic and static sport, in which much of the time the pilot is standing in balance or doing lateral movements without advance. We die-hard trial riders may like it, but the number of people that this type of trial attracts is much lower than the dynamic trial that was able to attract. Here we return to the previous points. Many off road fans prefer enduro or hard enduro (very similar to trial) because their preference is to “ride a motorcycle” and not“standing every little while placing and balancing” , which gives an image of a “boring” sport . This point is very important, since it makes many potential clients dismiss their interest in the current trial.

16- The stopwatch in the section does not solve the image of trials as a “static balance” sport. Yes, the time limit in the sections adds dynamism, but it doesn’t change the fact that the current basis of the sport is static balance in which Biketrial techniques must be mastered equally, with the added stress of having to do everything as quickly as possible. In summary, it does not solve the lack of potential clients who are interested in trial, although it may please some of the current fans. However, another large part of current fans reject the inclusion of the stopwatch in trial, since it is something that was never part of this sport. Trials is not strictly a ‘race’.

17- The No-Stop attempts to regain the dynamic image of the sport, but its application is difficult. Aware of all of the above for years, the motorcycle manufacturers and the FIM are trying to recover a less static, less indoor, and more dynamic image of trial “for riding a motorcycle”, which is closer to the origins and essence of the sport of the trials. For this reason, the old No-Stop regulation was re-intriduced, with which it wants to give a closer, less elitist image, which once again attracts potential new participants and followers. Regardless of whether or not the current youngest participants who have grown up in the “indoor” style like this regulation, the objective is to ensure the future of the sport by making it feel closer to the target audience again, and therefore have more ability to attract new participants. The problem is the difficulty of applying equally by all the section observers, which provokes the rejection of many riders and fans. In addition, for many, their personal interest prevails over the general interest in the subsistence of the sport itself, as is logical.

18- The evolution of trials has made the figure of the minder necessary. This did not exist in the early 1980s, but it was gradually introduced and its presence was recognized. As the sport changes with the incorporation of Biketrial techniques, becoming more static and with more indoor, more difficult areas, and with higher steps, it ends up becoming a fundamental safety element. The positive point is that it provides security, but the negative is that it currently represents one of the biggest expenses for each rider, leading to the impossibility of sustainability due to lack of finance. Today there are top riders who earn significantly less money than their minders, or who earn nothing.

19- The expenses for the competitor are increasing. Competing in trials is now much more expensive than previously, since the expenses are numerous: motorcycles, spare parts, tires, travel, accommodation, training, licenses, registrations, coaching, minders. Comparatively, the cost of licenses and registrations has skyrocketed, especially in countries like Spain. The expense increases notably in international events.

20- Motorcycle brands and importers cannot afford several official riders. The current volume of riders contributes sales of around 7,000 new motorcycles per year among all brands , with no growth but stagnation or decrease in recent years (in 1984 only Fantic sold 15,000 trial motorcycles). The figure is ridiculous compared to other off road sports such as enduro or motocross, and even more so if we compare it to mountain biking, for example. Despite everything, brands and importers make a huge effort to have official pilots and be present in world and national championships, and they can hardly afford to have more than one or two official pilots or increase their aid to semi-official pilots.

21- The low volume of sales of trials motorcycles causes the price of motorcycles to rise. To make its manufacture viable in such a reduced market, the only option is to raise the price, which harms us all. That is why it is essential to try to attract new fans to this sport, and try to ensure that its evolution is oriented towards it, making it a more accessible, more practicable sport, with a closer and less extreme image, regardless of the trial that each one we like it.

22- The mistake of comparing Biketrial to Trials. The motorcycle trial has an obvious parallelism with the evolution of the Trialbici or Biketrial. In view of all the points seen in this article, following in the footsteps of an even more minority and declining sport, “practically dead” for some, would be a serious mistake. More and more people maintain that when a top rider publishes videos doing zones on one wheel, they will get many “likes” on their social networks, due to the admiration that this high mastery of the motorcycle causes, but at the same time causes distancing from trial with their potential customers and therefore undermines its growth.

23- More specialized and less versatile motorcycles. Trial bikes have evolved to become extremely competitive and specialized, which has meant that they are only usable for increasingly extreme competition and therefore less valid for use at an amateur level that does not compete. In other times, the same motorcycles with which the professionals competed were used to make excursions through the countryside comfortably. This caused many trials bike buyers to switch to other options. Aware of this, the brands have recently begun to release their ‘Trial Excursion’ models, with larger capacity tanks, seat and even electric start.

24- The mistake of considering World Trials Championship as a show. The main objective of the world championships remains the same as the 70s, 80s and 90s, to show the image of this sport to the public with the aim of promoting it and making it grow, facilitating the sale of motorcycles and the entire related industry. This function cannot be forgotten or transferred to local amateur trials. Motorcycle brands are only interested in being in the World Cup or National Championships if it helps them sell their products. For this, it must be shown as a feasible, accessible, attractive sport, difficult by its nature but not impossible, without ever losing sight of its essence or its origins. It is true that it must continue to be the elite of the sport, but not become something that only 10 people in the world can do, because we would be back to the example of the trapeze artist.

25- It has been late to control the evolution of sport and motorcycles, which must be done by establishing limitations.The two previous points lead to this one, so that the trial does not end up becoming something else, something that for many has already happened. It is necessary that the evolution of the sport and its motorcycles be logical and not free, and for this to establish limits in the sporting and technical regulations. If this were not done, tomorrow the trial could be something like a fusion between the Biketrial and an EBike and it would stop being a motorcycling sport to become completely different. The entities that watch over the subsistence of a sport must try to maintain its essence, its origin. That is why measures arise that may not be understood but are necessary, such as the minimum weight limit on motorcycles, which also help to keep costs from skyrocketing.

26- Little interest from sponsors in a championship without possibilities, with a “fixed winner”. The current maximum level of the world championship is only achievable by no more than 10-15 pilots, of which only 5 have podium options and there is an almost absolute dominance of one pilot, which subtracts emotion and therefore interest. This decreases the chances of other pilots and therefore the interest of possible sponsors in them. Result: it takes away the interest, the emotion, and with it the money from the sponsors.

27- Low economic return of the sponsors in the trial. When a company decides to sponsor a rider, a team or a brand, it usually does not do so for charity, but in exchange for an economic return on their investment. A minority sport has less impact, but also a lower cost for sponsors. Therefore, the companies that can obtain a return that compensates them in the sport will hardly be the large corporations that seek to reach a massive amount of public, but rather those that have a direct interest in trial participants, such as accessory brands, motorcycle stores, insurance, sports or food products. Therefore, to feed this income generation, it is necessary for the volume of the trials market to grow.

28- Competitiveness and emotion, few options to fight for victory.A sport that attracts the public is a sport with uncertainty, with emotion, with an open struggle for victory among the greatest possible number of participants, representing the greatest possible number of countries. A company that decides to sponsor a professional pilot needs to have options to fight for victory, or at least to be in the leading positions. If the difficulty level is so high that only three drivers can fight to win, sponsors lose interest in sponsoring drivers other than those three. Therefore, the chances of fighting for victory should grow and for this the level would have to be lowered, making it more accessible to other pilots, as well as facilitating the incorporation of new young pilots, even if this harms a few.

29- Media and television. In the 80s and 90s the presence of trial on television was much higher, but the media broadcast what the public asks for, and if there is hardly any public interested in trial we cannot expect it to go back to the way it was before. Aware of this, federations such as the Spanish RFME are making a notable effort to broadcast summaries of the Spanish Championship events on television. Also along these lines, the FIM announces that it will broadcast the Trial World Championship via streaming on Youtube, this being a very good decision, as long as it does not become paid content, which would destroy the objective of doing so to spread the sport of trial and generate market.

30- Little support for specialized media and clubs. In line with the above, the work carried out by specialized trial media by fans of this sport, such as Todotrial, is little valued by some federations, brands, shops, since only a few support this dissemination work. Hiring advertising campaigns. In the same way, Motor Clubs often receive little help. This is the reason, together with the lack of a greater number of fans, for which there are so many motocross or enduro magazines, but hardly any for trial. Today, both clubs and magazines (on paper or digital) bring together the few fans who are willing to continue fighting for this sport, investing their work and time, which deserves a little more support and recognition that allows them to continue forward.

To conclude, there is a ‘Rupture’ between classic and modern Trials fans. This is a worrying and increasingly frequent symptom. Many veteran riders, and even some young people, feel less and less identified with the high level competition that is shown in the World Championship or even National events, losing all their interest. Many veterans think that today’s events are no longer trials but a different sport, and prefer to participate exclusively on classic motorcycles. Some young people also say they prefer this type of “classic” trials, whether on a modern or classic bike, and some declare that they are only interested in trials such as the SSDT or Santigosa 3 Days Trial. The case is even more evident when you discover that many trials fans have no interest whatsoever in the results of the World or even National Championships, so they are not even interested in going to see any of these events, and even less so if it is an indoor event. This leads to major opinion differences on issues such as regulations or even the inclusion of minders. This division is undoubtedly detrimental to trials in general.

Many thanks to todotrial for allowing their permission to reproduce their original article, published on 13th April 2023.

Gearhead Alert 015

Jon Stoodley of JSE Trials, Muskogee, Oklahoma talks us through….


Let’s talk about Carburetors. They can be fairly simple, like the pictured flat slide Keihin PWK or the Dellorto PHBL, both common on Trials bikes today. Or, they can be fairly complicated, Like the electronically controlled Mikuni on a YZ250 I modified. For this post, I’ll try to keep it simple and helpful for new riders.

Here’s one of my old articles about basic carburetors and jetting that might be helpful to newer riders. Trials engines are probably a little more difficult to properly jet and adjust because they must perform over a wider range of throttle settings, engine loads and ambient conditions than just about other form of motorcycle competition in my experience.

Here’s a couple of tips to get started. There seems to be some controversy surrounding adjusting the air/fuel screw for some reason. I’ve had riders argue with me that the factory setting (number of turns out) is what it should be set at, period. Other riders tell me that they read on the Internet that so many turns out is recommended by an “Expert” and that’s what it is supposed to be.

Here’s how I do it before each ride. The air/fuel screw “fine tunes” the low rpm circuits to handle the low-speed throttle response by compensating for changing ambient weather conditions (temperature, barometric pressure, humidity etc.). I warm up the engine to operating temperature, place it in Neutral and quickly “blip” the throttle (quickly open the throttle and let go of the grip) and adjust the air/fuel screw in or out to get the best engine response. For ever how many turns out I end up with (no matter how many turns out), that is the best setting, for this specific day, and under these specific weather conditions. This is why the screw is adjustable. I add knurled knobs to the air/fuel and idle screws so I can adjust them easily with gloved hands. When you bottom out an air/fuel screw, do it very lightly as they, like suspension adjusters, can be delicate and easily damaged.

Engine idle speed is generally a matter of personal preference, but I would suggest that you set it this way. Put the warmed up engine in gear, with the clutch lever pulled in normally the way you would ride which is usually back to a knuckle and not fully back to the grip. Then adjust the idle speed and in this way, you compensate for any “clutch drag” (GasGas riders take particular note). If you set the idle speed in Neutral, and you have too much clutch drag, when you are in a section stopped, or close to stopping, clutch drag will pull down the rpm below where you set it and you will have a much greater chance of stalling the engine.

A slight amount of clutch drag can be a positive thing as it keeps the engine’s drivetrain “loaded” (mechanical slack taken up) so that clutch modulation is much smoother than if the clutch released totally. This is particularly important under less-than-ideal traction conditions and slow going. Say you were in a tough section almost completely stopped, full-lock turn, off camber, muddy with roots, the clutch modulation (if it totally released) would result in a “jerky” take-up (and loss of traction) as the drivetrain loaded and unloaded.

One of the most frequent questions that riders ask me about is how they can properly set up their jetting. It seems like a lot of riders put up with poor performance from their bikes without realizing that, with a little time, effort and most important, a basic understanding of how that nasty little piece of aluminum and brass that some engineer stuck on their engine works, things could be a lot better. I’ll try to give a crash course (excuse the term) on what the carburetor is required to do and how you can help it do its job better.

Why would we need to change jetting anyway? Jetting doesn’t change by itself unless there is a mechanical problem in the carburetor. Conditions outside of the carburetor change and they have an effect on the engine’s air/fuel requirements.

For example, most bikes are jetted rich from the factory when they are assembled because they are shipped to various countries with a wide variety of conditions and fuel. The engineers can’t possibly anticipate and jet for all the conditions and areas they ship to, so they put in “safe” (ie rich) jetting with the idea that the individual rider or dealer will make the final adjustment to the engine requirements.

Riders who travel to different Trials find that their engines don’t operate as efficiently as they desire unless they adjust the jetting to suit the area. You may have bought a used bike that is jetted incorrectly (jetted for high altitude and brought down to sea level) and want to set it up for the area where you ride. Temperature, humidity and altitude have a direct effect on the amount of oxygen available to the engine. Ask any Ute Cup rider how much of an effect altitude has on engine performance. Fine tuning an engine to maximize performance is so important in racing that years ago when I was campaigning fuel dragsters, we would build special engines just for high altitude competition and we would refer to them as our “Denver motors”.

What is a carburetor and what does it really do? A carburetor is a device that atomizes fuel with air and meters that mixture to the engine over a wide variety of throttle openings. The stoichiometric (or, chemically correct) ratio under perfect conditions of the air and fuel is 14.7 pounds of air to one pound of non-oxygenated gasoline, although AF (air/fuel) ratios in the range of 12/1 to 14/1 seem to produce the best power in motorcycle engines.

Trials engines seem to work better on the lean end of the A/F ratios due to the conditions that they operate under. You can see that if your carb had only one metering orifice (jet) it wouldn’t be able to maintain that ratio from closed to full throttle opening. That’s why they have all those other fuel and air metering gizmos, in order to adjust the amount of fuel to the amount of air allowed into the engine by the slide opening from almost shut, to wide open.

Most modern carbs have six (and sometimes seven, a “power jet”) different air and fuel metering jets that affect the fuel mixture over the range of throttle openings. Those are the air screw (sometimes this a fuel metering needle), throttle slide, air jet, pilot jet, needle jet and main jet. Most riders can just replace the pilot and/or main jet to get the desired performance and fine-tune the engine with the air/fuel screw and needle clip adjustments.

Let’s look at where those little thingies do most of their work. The throttle settings and the air/fuel jets that affect the air/fuel ratio at those openings are:

-Closed to 1/8 throttle opening – air (or fuel) screw, pilot jet

-1/4 to ½ to full throttle opening – throttle slide, jet needle

-1/2 to full throttle – jet needle, needle jet, main jet, air jet

As you can see, most of the air/fuel circuits overlap in their functions so it’s not a black/white decision as to what to change and how far to go rich or lean. A savvy tuner spends a lot of time looking for the signs that the engine exhibits in order to make a well-educated guess, and its not unusual to see such tools as exhaust gas analyzers, air/fuel electronic sensors and relative air density meters used at the professional level of racing.

What do all those numbers and letters stamped on the parts mean? In the pilot and main jets the larger the number, the richer the jet. On the slide, the larger the number, the leaner it is. Needles have various codes, but as a general rule the smaller the number (if it doesn’t have letters), the richer the needle. To richen the needle setting when it is installed in the carburetor, lower the circlip one groove at a time. And to lean the needle, raise the circlip in the grooves (lower clip = raise the needle and vice versa).

Air/fuel screws are a little trickier. Although they may look the same, an air screw is turned clockwise to richen the mixture but a fuel screw is turned counter-clockwise to richen the mixture. To tell if its an air or fuel screw, look at the carb from the side. If the screw is located on the carburetor towards the front of the slide (manifold/reedcage area), it’s probably a fuel screw. If it’s located towards the back on the carburetor (air box side), it’s probably an air screw adjuster. Air screws usually have a blunt end and fuel screws have a sharp needle-shaped end.

The air jet, and sometimes the needle jet, are usually not replaceable on some carbs. For example, the needle jet is replaceable on most Keihin carbs and on most Mikuni carbs.

The numbers on jets, throttle slides and needles will allow you to tell how rich or lean they are from stock settings. The jets are stamped with their numbers but don’t be confused by the radical difference in the numbers between models of carbs as some jets are rated according to flow rate and some are rated according to the metric size of the orifice. For example, a 172 Keihin jet is roughly equivalent to a 350 Mikuni jet in Motocross bikes.

Needles have the number or letters stamped at the top by the clip slots. Those numbers or letters relate to the thickness and taper of the needle which will dictate how much fuel it will allow to flow around it as it is retracted out of the needle jet by the slide as the throttle is opened.

As the needle is tapered, the more it is pulled out of the needle jet by the slide, the more fuel it will allow to pass into the throat of the carb, relatively speaking. A thinner needle will pass more fuel around it than a thicker one, and it therefore a “richer” needle. Some needles have compound degrees of taper that allow individual adjustments to various throttle settings. Slides are usually stamped on the bottom front of the slide. That beveled cut on the front of the slide, near where the needle comes out (called the cutaway), has numbers that usually relate to the height of that bevel from the bottom of the slide. A #4 slide will have the top of that bevel 4mm from the bottom of the slide, a #5 slide will have a bevel 5mm high, etc. The higher the number, the leaner the slide as higher bevels allow more air to be funneled over the needle jet tower (that little protrusion that the needle retracts from in the center-lower part of the carb throat).

Before we set out jetting, we must eliminate the possibility that other problems exist that could have an effect on the jetting requirements of our engine. The engine must be in good shape with no leaking crank seals, broken reeds, air leaks in the intake system or crankcase, weak ignition system, cylinder head coolant leaks or blown-out packing in the muffler. The carburetor float level must be a factory specification, the fuel inlet float level needle must not lead and the vent hoses should be replaced if there is any possibility of clogging. Also, check to make sure that the air cleaner is clean and the engine has fresh pre-mix.

As far as special tools are concerned, you should have a good metric scale short ruler (for float level), a small magnifying glass to read jet/needle stampings accurately (Mikuni jets are notorious for being hard to read because of shallow stampings), a long, narrow screwdriver for pilot jets, a long 6mm socket for hex jets and good sharp screwdrivers, as the screws and brass jets are soft and you’ll have a hard time extracting them after you’ve rounded them off with poor tools.

As far as jets are concerned, I usually buy one size larger and three sizes smaller than stock on the main jet, and one size larger and two sizes smaller than stock on the pilot jet. I’ve usually never needed to go out of this range when jetting bikes from below sea level to about 8500 feet. A good way to store jets is in a film canister between layers of foam so they don’t rattle around.

Now for the actual jetting ritual. First, try to figure what throttle setting is not responding well by riding the bike in a practice section. Atmospheric changes have a dramatic effect on the amount of oxygen available to the engine, as mentioned before.

Higher temperature, altitude and humidity will sometimes require going leaner on the jetting. Lower temperature, altitude and humidity sometimes call for richer settings. Decide what jet to change according to what throttle setting needs adjustment. Only change one jet at a time. If jetting is a new experience for you, always start by going rich at first. This is safer than initially going too lean and it will give you a direct experience of how an engine acts when it’s running too rich.

Diagnosing jetting by listening to the exhaust note takes experience as even practiced ears can sometimes have a problem discerning the difference between a “surging” (lean) and a “bogging” (rich) sound coming from the exhaust pipe. If the engine runs worse with your change, then go two steps leaner, which will actually be one step leaner than where you started. The engine will tell you if you’re on the right track. Test the bike again to see if that solves the problem but keep an eye on spark color (it should resemble a milk chocolate color with most grades of gasoline) with any changes of the needle or main jet.

Let’s look at some common conditions and possible adjustments, starting with what to try first.

-ENGINE RUNS “FLAT” AT MID-THROTTLE – Adjust the needle, change main jet

-ENGINE STUMBLES WHEN THROTTLE IS OPENED FROM IDLE TO 1/8th – Adjust air/fuel screw, change pilot jet

-THROTTLE OPENED QUICK, ENGINE BOGS THEN CATCHES – Adjust air/fuel screw, change pilot jet, change needle clip position

-ON LONG UPHILL, POWER STARTS OUT OK, THEN FALLS OFF – Check for blocked vent tubes


Here are some hints and tips that might prove helpful:

-Gray, thick wall Tygon fuel line is the best I’ve found. Some small engine repair shops can get it for you. Be sure that it’s Tygon type, as that’s the tubing they make for use with fuel. The clear is not as good. For dusty, dry conditions, keep an extra, clean/oiled air cleaner in a sealed plastic bag to use in the Trial in case practice has gunked up the one on your bike. This will keep the engine from running rich. Run the vent lines of the carb relatively short (about 4-inches), as fuel can collect in longer lines and a hard hit, like splattering rock step, can cause the fuel globules to quickly drain out of the lines (creating a partial vacuum), and lower the float bowl pressure, making the engine bog. If you like long lines, run a “T” fitting at the vent hole and run the top line up under the fuel tank. This will allow the fuel to drain out without lowering the float bowl pressure.

-Check the spark plug color often to monitor mid and upper range jetting. Run a fuel filter. I like the small cone-shaped, sintered brass, clear ones. You’d be surprised how much gunk can collect in your fuel can and make its way into the fuel tank and then clog the float needle and possibly the jets. Don’t forget to clean the filter on the sides of the Dellorto carbs once in a while.

-Clean the throttle often and make sure there are no kinks. It’s a good idea to safety-wire the ends to the housings. Drain your floatbowl after wet weather Trials. Most standard bike service manuals have altitude/air temperature jetting correction charts with instructions for use. Ask a buddy who has one if you can copy it and keep it in your toolbox. They can come in handy. Keep a notebook in your toolbox of any jetting changes (along with ambient weather conditions) when you travel to a different Trials area so when you return, you have a good place to start when setting up the bike again. This goes for any other changes like tire pressure and suspension settings, too.

This should give you a good place to start. Take your time. Properly jetting an engine isn’t as esoteric as a lot of riders seem to believe it is.

That’s it for now… or have a look at my other Gearhead Alerts

Jon Stoodley, Muskogee, Oklahoma

Suzuki Made in Canada

The title is perhaps a little misleading, but here we have a custom-built 125cc Suzuki trials machine which has been made in Japan, re-engineered in Canada, by a Scotsman.

The machine is the proud possession of exiled Scottish superenthusiast, Stuart J. McLuckie who lives in Thunder Bay in the province of Ontario, Canada and it is probably better described as the Mark 2 version of a machine he built and developed in the early 1970s when riding trials in his native Scotland as a member of the Edinburgh based Melville Motor Club.

Born in 1951, Stuart studied on day release at the old Napier Technical College in Edinburgh and took up employment at St Cuthbert’s Co-operative Society in the city. In fact the same company that gave Sean Connery of James Bond fame a job as a milk delivery boy!

Stuart worked as a mechanic on the company vehicles based at their Fountainbridge headquarters. At the time he lived in the Comiston district of Edinburgh and took up trials riding in 1968 riding a Greeves at the annual Edinburgh St. George Evening news Trial, progressing to a Cotton. He shared transport to events with Douglas Bald and on occassion, Ernie Page. He rode the first of his Scottish Six Days Trials in 1970 on a 247cc Montesa.

Stuart met his wife to be, Wendy Kingon-Rouse at the RAC/ACU Motorcycle training scheme at Edinburgh’s Gorgie Market, the scene of many SSDT first day starts. Wendy was a keen motorcyclist and was learning to ride on an Excelsior scooter, then progressed to a brand new 125 Suzuki, supplied by Graeme P. Chatham’s Abbeyhill dealership. Stuart also took up riding motocross in 1970 on a 250cc CZ.

The outgoing, effervescent McLuckie was also one of a gaggle of trials, speedway and motocross riders who took part in Scotland’s Ice Racing venture in 1972. Using modified 175cc Greeves/Puch Pathfinder trials machines, sourced from dealers in Scotland, they raced indoors at Edinburgh’s Murrayfield Ice Stadium and at Aviemore. Wendy and Stuart eventually married and emigrated to Canada in 1974.

Around 1971, Stuart had struck up a friendship with Edinburgh dealer, Graeme P. Chatham, who was the main promoter of the Scottish Ice Racing venture along with Trevor Hay. It was from this friendship that spawned the special Chatham Suzuki trials machine, developed from the 1972 TS125 Trail model.

Stuart McLuckie: “We took a brand new TS125 from Graeme’s showroom in Abbeyhill, it was registered YWS11K and loaded it onto my Mini pickup and I set about stripping it all down at home. The bits I didn’t need were returned to Chathams and sold off as spares or used in their workshops to repair damaged machines.”

The TS125 was powered by a 123cc five speed motor which pushed out a creditable 9.7 BHP at 6,400 RPM.

Handily, the TS125 came with 21 inch front and 18 inch wheels which was ideal for trials use, but the little Suzuki had steel rims as standard, so an Akront flanged rim was fitted which took a 4.00 section trials tyre on the rear and an unflanged mudshifter style Akront with a 2.75 section up front. The original metal side panel ‘125’ badge was retained fitted to hand made alloy side panels and the original TS125 fuel tank was gifted a couple of sculpted indents at the nose to allow for tighter full lock turns.

McLuckie: “I admired what Peter Gaunt had achieved with his first Suzuki based on the 120cc Trail Cat, then another later version using the TS125 and I wanted one just like it, the TS125 was easily sourced and I got to work making a trials bike out of it.

The idea also came from a Suzuki (JOV198E) that Trevor Hay had from 1968 until 1971 which came from Suzuki GB and had been an ISDT bike converted at Chathams for one-day trials use.” Trevor handled Chatham’s advertising, so that was the original Chatham connection I suppose.”

McLuckie rode the Chatham Suzuki, called the ‘TC125’ in all the Scottish national events including the Loch Lomond Two Day trial. He made improvements constantly and the bike created much attention at the time and useful publicity for the Chatham dealership.

Time goes by and Stuart makes his living as a skilled machinist in Canada, but retained his love of all things motorcycling and embarked on various projects, building trials specials to amuse himself over the years. But there was a hankering to recreate the little Suzuki he enjoyed riding in his twenties in Scotland. Over the years, he kept a vast photographic collection of his engineering exploits and is always happy to show them to those that have an interest in trials machines.

The original Chatham Suzuki has long since disappeared having been sold into private hands in the mid 1970s.

How the ‘Mark 2’ Chatham Suzuki was created:

Having retired from the Port Arthur Shipbuilding Company working as a machinist for thirty-seven years, the winters can be long at Thunder Bay and Stuart McLuckie gets restless if he hasn’t got a project to keep him busy.

So, to keep him out of mischief, in 2019, a worn out 1973 Suzuki TM125 motocross machine was sourced as the supply of TS125 model was, by now, virtually non-existent in Canada. This was to be married with a 1976 TC125 motor which was pretty much worn out. The TC motor had a four speed high/low gearbox.

McLuckie: “The frame has been modified front and rear,  steeper fork angle, and the rear subframe this all new. The wheels and hubs are original, rebuilt with stainless spokes and a lot of polishing. The forks are original but need some work on them, a wee bit on the stiff side. I hope that Peter Gaunt is up there smiling as he was the original inspiration?”

Stuart sourced the opaque white plastic mudguards from the UK through InMotion in Egham, Surrey as they looked better than other plastic guards on the market. The original Chatham Suzuki sported the popular VF (Vaccum Formers) black plastic guards of the period, now unobtainable.

Finished in a lovely metallic blue, as a nod to the Mark 1 Suzuki of the 1970s, Stuart has adorned it with tasteful decals which reflect the Scottish/Canadian connection and his trademark ‘Up Yer Kilt’ decal is on the front number plate.

A small decal on the tank spine, proclaiming ‘Made in Japan, Re-engineered in Canada’ is typical of the fun-loving Scotsman who is known for his quick witted, highly amusing comments.

Without a doubt, the Chatham Suzuki Mark 2 is a stunning little trials machine and if it performs as good as it looks them Stuart J. McLuckie’s time has not been wasted. No doubt this will not be the last of his winter projects, because you can’t keep a good Scot down!


AJS 37A-T Too Little Too Late



AJS, the brand purchased by Associated Motor Cycles in 1931, were known for their long-stroke single cylinder trials machines, which partly dominated the competition scene in the late 1940s and throughout the 1950s.

This culminated in Gordon Jackson’s historic Scottish Six Days win on one solitary mark in 1961, achieved with a factory-prepared 16C with a special short-stroke motor.

Associated Motor Cycles (AMC), the group which also owned the Matchless, James and Francis Barnett brands, hit financial difficulties around this time and the writing was firmly on the wall; all these brands had a competition history.

The root of the problem lay with the directors at AMC having taken offence at a critical report published on a road test on one of their machines.

Their response was to refuse permission for the motorcycle press to test their machines and their advertising campaigns in the weekly papers ceased, so not surprisingly they lost valuable sales, year on year, through lack of exposure to the buying public.

It was a case of cutting off one’s nose to spite one’s face.

Words: John Moffat (Trials Guru) – Tony Davis – Norman Edgar – Colin Dommett – John Pye.

Pictures: Yoomee Archive/ Malcolm Carling – Yoomee Archive/Alan Vines.

AJS Two-Strokes:

Two-strokes had been gaining popularity and in late 1964 Sammy Miller announced that he was moving to Bultaco from Ariel, which in itself was to become a game changer for the trials scene and heralded the Spanish invasion by Bultaco, followed by Montesa in 1967 and eventually Ossa. Two-strokes were here to stay.

The AJS brand, along with the others in AMC, had been taken over in 1964 by Manganese Bronze Holdings which had already bought Villiers Engineering.

After the AMC Plumstead factory closed in 1966 with the creation of Norton Villiers, this involved restructuring of the group and AJS moved to Wolverhampton.

The plan was to continue in the competition market, producing only off-road AJS machines at a new purpose-built factory at Andover, but due to planning permission delays the new factory only became operational in mid-1969.

The AJS Y4 ‘Stormer’ motocross machine which was powered by the Villiers ‘Starmaker’ motor and developed over the 1968 season and would take Malcolm Davis to British Championship victory on the works prototype.

They signed Chris Horsfield, Malcolm Davis, Andy Roberton, Sweden’s Bengt Arne-Bonn and Scotsman Jim Aird to field a strong motocross contingent.

They also had an eye on the trials machine market which was buoyant, and they had access to the Villiers two-stroke motors, being under the same group of companies.

Malcolm Davis was not only an excellent motocross rider but also an exceptionally talented trials rider.

Starmaker Engine:

The Villiers 37A powerplant was to be used for the new AJS trials machine in 1969.

The Villiers ‘Starmaker’ engine was to be the basis for the new motocross machine. It was developed from Peter Inchley’s 1966 ‘Villiers Starmaker Special’ TT racing machine which came home third in that year’s Lightweight race. Inchley’s prototype for AJS was based on a Bultaco racing chassis.

The Starmaker had previously been developed by Cotton in their Cobra motocross model and subsequently installed in the factory prototype AJS motocross model first raced by Andy Roberton.

Further developed, it carried Malcolm Davis to victory in the 1968 British MX Championship and from this the Y4 ‘Stormer’ was born. The 250cc Y4, launched in 1969, was followed by big-bore Starmakers, the Y5 Stormer at 360cc in 1970 and eventually the ‘410’ Stormer of 410cc in 1972.

Inchley was a former BSA employee who moved to work at Ariel on two-stroke development followed by a move to work with Dr Joe Ehrlich at EMC, joining AMC in 1963.

Reynolds Tubes constructed the new road race frame, constructed by ace welder Ken Sprayson. An AJS was entered for the 1967 TT but while in fifth position his bike was filled with neat petrol instead of two-stroke mixture and Inchley was forced to retire with a seized engine.

Cotton involvement

A year later AJS commissioned Cottons of Gloucester to make a frame for trials use loosely based on the existing Cotton trials frame but incorporating the large diameter top tube of the Y4 motocross design. For trials they had access to the proven ‘37A’ trials motor.

Cotton had used the trials version of the Starmaker as early as 1964 – more on this later.

John Pye was After-Sales Manager at Malcolm Davis Motorcycles in Gloucester: “I remember Malcolm Davis, ‘Fluff’ Brown of AJS and me travelling to a local farm to test a new AJS trials machine that the factory was experimenting with. It was basically a Cotton but the main difference was the top tube, which made its way into production by late 1968”.

Tony Davis, Malcolm’s brother was an accomplished trials and motocross rider who had ridden the factory BSA B40 and for Greeves, and he was enlisted to ride an AJS supplied by the factory. Issued with a standard 37A-T registered TFH22G it came equipped with Metal Profile telescopic front forks, British Hub Company ‘MotoLoy’ six-inch alloy full-width hubs and, of course, the 37A 246cc Villiers engine with an iron cylinder barrel. It is surprising that AJS did not incorporate an aluminium barrel and cylinder head combination as Greeves had done many years previously, and the now well established Bultaco Sherpa and upcoming Montesa Cota both used all-aluminium engines.

Tony Davis: “I rode exactly what the AJS factory supplied us with in 1968. AJS boss Peter Inchley was a stickler for using only factory products, no other components were allowed”.

John Pye: “I remember when Malcolm was in the shop when Peter Inchley arrived and Malcolm hid from him for quite a while. It transpired that Malcolm had bolted a set of Spanish Betor front forks on his motocross AJS. Inchley took one look at the AJS and asked what all this was about. Malcolm explained that he found the Betors helped the front end, but Inchley would have none of it; he insisted that the AJS forks were re-fitted immediately!”

Heralded as the ‘AJS 37A-T – Britain’s latest trials model’ Malcolm Davis was to be credited with the development work for the new machine, as highlighted in the company sales literature, and it was launched in time for the 1969 trials season.

The Edinburgh Connection:

Up in Scotland the appointed agents for AJS were Edgar Brothers in Leith Walk, Edinburgh. They were already sponsoring Jimmy McRae for the 1969 Scottish Championship season on the new Y4 Stormer.

McRae later went on to become five times British Open Car Rally Champion and, of course, the father of 1995 World Rally Champion, Colin McRae MBE.

Dealer principal Mr Norman Edgar was keen to sell as many AJS models as he could, and both his sons were accomplished trials riders. His son Norman FW Edgar was at that time twice Scottish Trials Champion and had entered the 1969 ISDT to be supplied with a works-prepared AJS Y4 ISDT machine for the event at Garmisch-Partenkirchen. He had been campaigning a 37A-T in Scottish and national trials.

It was registered NFS21G in the October 1968 and competed with it into the spring of 1969.

Former Scottish Trials Champion, Norman F.W. Edgar in the 1968 British Experts trial on the first of his AJS 37A-T machines, previously he rode Puch trials machines.

He and his younger brother Derek J Edgar were also experienced SSDT competitors, and both had entered for the event to be held in early May.

Scottish Six Days 1969:

AJS were keen to push their new trials model 37A-T in the Scottish Six Days, and to field a team of three riders comprising the Edgars plus one other competitor.

Mr Edgar noticed that Yorkshireman Ray Sayer had entered on his four-stroke 500cc Triumph so an approach was made to enlist him on a 37A-T to make up the three-man team.

Sayer saw the sense of riding a lighter two-stroke and agreed. AJS were to pay for the three team member entries but as for the machines themselves, that was a different part of the story.

Edgar contacted the AJS factory and enquired what would be available for the SSDT to be informed that, due to workload, they could not guarantee to build three suitable machines in time. Could the Edgar Brothers build bikes from parts supplied? Mr Edgar agreed to the offer, and boxes of components were despatched to Edinburgh from Wolverhampton and three AJS 37A-T machines were assembled by Derek Edgar in the dealership’s workshop.

Norman FW Edgar: “It is over 50 years since I rode the AJS in the Scottish, so apologies if I can’t remember full details or the sequence of events, but somehow we decided to change the specification. We obtained new front forks and front and rear wheel hubs from the scrambles Y4, which not only looked much more purposeful but were also lighter than the standard full-width items fitted to the production models. We also fitted longer than standard aluminium side panels to protect the air cleaner. As was always the case, if we could get something to work better, we did it. When I rode the ISDT later that year, I changed the motocross piston for a trials component before the event and the machine’s power delivery was much more suited to the ISDT. Derek built the three SSDT machines, and these were registered in Edinburgh and tested just immediately prior to the Scottish”.


The Edgar-built 37A-Ts were registered OWS 11, 12 and 13G. Derek rode 11G, Norman was given 13G and Ray Sayer rode 12G.

Another AJS, OWS14G, seemed to be registered at the same time, but this was probably a standard 37A-T machine for a customer.

One of the three SSDT machines ended up with the Kingston & District club in Surrey as a loan motorcycle for those wishing to sample the sport, the machine having been traded in to Comerfords at Thames Ditton and failing to sell through the shop around 1974.

Looking at close-ups of Derek Edgar’s SSDT AJS, which he used again in 1970, it would appear that he had fitted a German-made ‘Bing’ carburettor for his attempt at the Scottish for the second time on the 37A-T.

Derek Edgar was an innovator and had also ridden Puch machines in trials and the ISDT for a period prior to building the AJS. He later went to work for Puch in Austria as a development rider and technician.

Norman continued: “I do remember Ray Sayer mentioned something about the steering lock being restricted and, indeed, he took a hacksaw to the front end at Gorgie Market during the SSDT weigh-in on the Sunday. Both Derek and I did not really notice anything untoward, so we just rode the machines as they were built”.

At a wheelbase of 51.5 inches, by utilising the Y4 forks and alloy yokes with the leading axle it would stretch the AJS 37A-T to around 52.5 inches – more in keeping with the Bultaco Sherpa – and assisting stability on straightforward rocky sections, which was a feature of the Scottish Six Days. Fortunately the Y4-style fork sliders were not ‘handed’ and had sufficient lugs to accommodate front mudguard fixtures.

Norman Edgar in the 1969 British Experts on OWS13G, one of the Edinburgh built AJS factory bikes, note the ‘Stormer’ wheel hubs, front and rear.

And so AJS fielded a team in the SSDT, the first time since 1965. Too late to be printed in the official programme, and Ray Sayer shown as riding the 500cc Triumph, it was not to be a ‘dream team’ situation, with Sayer dropping out of the trial on the Wednesday with gear selector problems. His machine was repaired post trial and retained by the Edgars and used again in 1970, this time piloted by American Bob Ewing who flew over from California. Derek Edgar took up employment with Ewing after he left Puch and before he went to work for Montesa USA.

Modifications and Improvements

Having informed Tony Davis that the Edgar brothers and Sayer had ridden heavily modified 37A-Ts in the Scottish, he commented: “I find this surprising in that Peter Inchley was such a stickler for us riding what we were given, and yet the Edgars changed the machine materially. Perhaps because they used AJS components and the fact the factory could not supply prepared machines meant it was acceptable”.

Photographic evidence confirms that Malcolm Davis used the Y4 alloy conical front hub on his AJS, SFH96G, in the Cotswold Cup Trial in 1969 but retained the standard Metal Profile forks with the axle at the bottom of the slider.

Malcolm Davis on his factory AJS before he secretly changed the front hub to that of the ‘Stormer’ conical version.

It would also appear that he went against Peter Inchley’s instructions by fitting a Greeves aluminium barrel and cylinder head to his 37A-T!

Even though the Edgars changed the geometry of the 37A-T they were not in a position to change the most obvious component, the cylinder barrel; this was still the iron unit.

Greeves achieved it, why not the AJS factory? After all, the owners of AJS, Norton Villiers, intimated in 1969 to Greeves that supply of Villiers power units would cease, which inevitably forced the Thundersley firm to source engines from Puch in Austria.

Why the 37A?

AJS had all the development work done on the all-alloy Starmaker unit, could they not have further developed the trials version of that power plant?

Bultaco for example developed their Sherpa trials and the Pursang motocross motor from older applications, the motocross having different porting and gear clusters, but benefitted from common components and were all-alloy construction.

As already mentioned, the Starmaker trials version had been used in the factory Cottons with one issued to their supported rider, Colin Dommett, in 1964.

Colin Dommett: “I didn’t like the Starmaker engine, for example the gear ratios were too wide, and it was eventually sent back to Villiers as I think they owned the engines. It was replaced by a 37A engine. They tried all sorts of exhausts, but everything they did just made things worse, not better. I think they even tried a 37A crank in a Starmaker and that was a slight improvement”.

The Villiers ‘Starmaker’ all alloy motor which was used by Cotton and also AJS for their ‘Stormer’ motocross machines. Three versions were produced for racing, motocross and trials.

Cottons also fielded a team in that year’s SSDT fitted with Starmaker motors, comprising Arthur and Alan Lampkin and Blackie Holden. All three riders finished with special first-class awards.

The belief was that the 37A, although using appreciably heavier components, was the better engine for trials use even though it looked old fashioned compared to the compact-looking Bultaco and Montesa power plants.

As well as being second best Edinburgh & District club member, receiving the Henderson Challenge Trophy at the SSDT, Norman Edgar Jnr won the 1969 Scottish Trials Championship outright on his 37A-T, making him a three times champion in the process.


It’s all well and good having factory machines entered for major events like the SSDT and British Experts, you still need sales to private owners to make it financially worthwhile.

There were six private entrants on AJS 37A-T who rode the 1969 SSDT: M.K. Fulcher, North London; R.E Chapman, North East London; Jack Young, Edinburgh; Roger Davy entered by Comerfords (WPD4G); and Chris Watts of the C.S.M.A. (TAE411G) who also had fitted a Y4 front hub on his 37A-T.

Chris Watts on his 37A-T AJS showing that he too favoured the lighter front hub from the ‘Stormer’ motocross model.

There was one other AJS entered that year, but it was a 350cc four-stroke 16C ridden by JL Smith from Edinburgh, a nephew of Scottish born AJS director Bill Smith.

American Bob Ewing had entered in 1969 but was classed as a non-starter so the best guess is that he would have ridden OWS14G, either that or Jack Young could have obtained it just prior to the event.

The following year there were four AJS mounted riders in the 1970 SSDT: Eddie Henderson from Bangor and member of the Knock MCC Ireland; Bob Ewing, who flew over from California to ride the OWS12G supplied by the Edgar Brothers; Jack Young, from Edinburgh; and Derek Edgar, back on OWS11G. But most of the entry by now consisted of Bultaco and Montesa with a couple of Ossas.

Tony Davis Talks AJS:

“It was Malcolm who talked me into riding the AJS trials machine; ‘fly the flag’ he said. So I agreed to ride it for a year. We spent many hours practising in the quarry and woods up the hill near the Air Balloon. We both found it ‘gutless’ from plonking in a section, and the carburetion was unreliable. After many hours’ tuning we got the carburetion more exact. Malcolm did a lot of work on the engine and got it to respond better and rev out more, which suited his style of riding. Peter Inchley wanted my machine to stay as standard as possible. It handled reasonably well; it was better in mud than on rocks but was never going to be a world beater, especially against the Spanish armada. I won some centre trials and the Western Centre Championship was mine once again. The AJS was far too late to win any National trials, and the ‘powers that be’ knew that. Now the Y4 Stormer motocross model was exceptionally good, as Malcolm proved”.

Studying old national trials results, it is evident that Tony Davis’s overall performance improved when he switched to Bultaco in 1970. It was by then a tried and tested product, which had benefited from not only Sammy Miller’s input but that of riders across the globe who enjoyed support from the Barcelona manufacturer. Bultaco and Montesa were taking trials very seriously, and with Mick Andrews developing the Ossa they too were ready to capitalise on the success of their prototype.

Tony Davis on his factory supplied 37A-T AJS


Sales of the production AJS 37A-T were disappointing; trials riders are consistent followers of fashion and the AJS just did not inspire them.

The tank was quite bulbous and was the bright orange – the factory called it ‘Bushfire Red’ – fibreglass unit taken from the Y4 model. The frame was superbly finished in metallic silver but had an unusual plate which joined the large-diameter top tube to the footrest tubes, and it had a full cradle, single down-tube frame.

Chain adjustment was not made at the back wheel but at the swinging arm pivot, with an eccentric cam arrangement that was an attempt to keep the chain line as straight as possible.

It was used on the AJS motocross model and also used by Rickman on their motocross Metisse frames, but it was unusual for a trials machine. Carburetion was taken care of with a Villiers S.25, which is the type of carburettor that would become popular with the Pre-65 brigade in the 1990s.

Again this was a departure from the trend, which was to use the modern AMAL MK1 concentric which was fitted by both Bultaco and Montesa at this time, the instrument made in Spain under licence from the UK company.

Remember, the AJS was competing for sales against these two Spanish brands which had already gained a foothold in the UK, North American and European trials markets.

The engine, as stated, was the iron-barrelled Villiers 37A model which had a bore of 66mm and stroke of 72mm, giving a displacement of 246.33cc and a claimed 12.4 BHP at 5,000 RPM. Compression ratio was quoted as 7.9:1.

In comparison, the 1964 trials version of the Starmaker pumped out 15 BHP at 5,000 RPM. Utilising a 58-tooth rear wheel sprocket, the 37A-T gave a 29:1 bottom gear, with a four-speed gearbox giving ratios as 3.6; 2.4; 1.56 and 1.00.

The wheels were built using Dunlop chrome steel rims whereas the Spanish competition were using Akront alloy components at this time. Mudguards were plain polished aluminium alloy, with front mudguard bracketry fabricated from sheet alloy and an alloy chainguard, standard fit for trials machines of the era.

A heel/toe gear lever, chrome plated ‘Peco’ style exhaust and Girling rear dampers finished the package off. List price in 1969 was £228 and ten shillings, in kit form thus avoiding Purchase Tax.

AJS Today:

John Moffat of Trials Guru makes comment:

Information on the 37A-T is very scarce on the internet, purely because of the short production run and the low numbers produced and sold. However, the model is featured in Gregor Grant’s ‘AJS – The History of a Great Motorcycle’ published in 1969, revised in 1974 by Patrick Stevens Ltd, Cambridge (ISBN 0 85059 186 4). It gives a potted history of the marque from its creation and covers the Y4 Stormer and 37A-T models. It does lack, however, any detail of the trials model’s development, undertaken by the late Malcolm Davis, his brother Tony and of course the Edgar brothers in Scotland. Perhaps this article has covered the gaps left by a fellow Scot; his book is well written and researched as he was a professional journalist, but perhaps he did not have the connections to fully research the trials model or perhaps in 1969 thought it wasn’t important enough to save information on the new model for posterity! You simply cannot cram too much information into a book though! On a personal note, when I was 10 years old I started saving up my hard-earned pocket money with the intention to buy an AJS 37A-T. This was probably an idea cultured by my environment, because my Father had ridden an AJS four-stroke twice in the SSDT and then owned an ex-factory Matchless. I saved up the princely sum of £1:10s:6d by the September of 1969. However, my Father bought me a Dalesman Puch in the October, so the money went towards buying fuel! I was quite taken by the AJS which looked different from the selection of trials machines on sale, but it was not to be. I did come across OWS11G in November 2019 when I enquired if it was for sale, the owner lived in Carlisle. The owner, realising its history, wanted several thousand pounds as it stood. I found this over-priced; having been laid up for many years it was in poor condition. To its credit, it did look quite complete and still had the Y4 front end, but the cost to restore it would have been excessive. There was no question that it was Derek Edgar’s 1969/70 SSDT machine. I turned the deal down at the time as I felt it was a pointless exercise for me, but deep down I wanted to own the motorcycle, given its SSDT and Edinburgh history. I knew Derek Edgar very well and had a lot of respect for him. I have also subsequently heard that restored versions are being advertised more than that figure, due primarily to their rarity! With the BSA trials competition effort now defunct and Greeves already losing its way, I often wondered what AJS could have achieved had they invested more into the trials project and even recruited Sammy Miller, letting him have the trials version of the Starmaker engine, a clean sheet of paper and a free hand? Even as late as 1970 when Sam was just about over his riding peak, we can only speculate how the brand could have fared. The question must be asked, did the AJS management really take the trials market seriously, as they did not seem to act on the improvements made by the Edgar and the Davis brothers? The Spanish manufacturers were always taking serious note of what their supported riders told them and would make improvements for the next edition of their production models.

Production of the 37A-T AJS ceased and the model was discontinued in 1970.

Today, the AJS name and famous monogram lives on with the company ‘AJS Motorcycles Ltd’, run by Nick Brown and his family. Nick is the son of ‘Fluff’ (real name David) Brown; they manufacture homologated 125cc road-going scooters and motorcycles primarily aimed at the learner rider market. They operate from Upper Clatford, Andover, and still carry spare parts for the old Stormer motocross models, but not the ill-fated 37A-T.

Maybe the AJS 37A-T was, as Tony Davis said, ‘far too late’?

This article first appeared in Classic Trial magazine, Issue 34. For more information on Classic Trial Magazine, click HERE

Terry’s Dalesman Manx win

Words: Nigel Megson

Fifty years ago, the Manx National Two Day trial was held on Saturday 29th August and Sunday 30th August 1970.

The solo trial had two hundred and one starters and was over two circular routes that started at 8.15am from the famous TT Grandstand.

The Saturday route traversed the south of the Island and had thirty-four sections  and the Sunday route went over the North of the island and also had the same number of sections.

On paper, the favourite looked to be Gordon Farley who had travelled all the way from Kent and who would be riding his works supported 250cc Montesa Cota. He would be up against Expert riders from West and South Yorkshire, many of whom were riding ‘mini’ 125cc bikes. Riding numbers probably favoured the top runners, who were starting from the middle of the field as the riding order was reversed for the Sunday.

Dave Thorpe on the 250cc OSSA ‘Pennine’ was riding number 68, Terry Wright on his Dalesman was riding number 92, Gordon Farley with number 126, Gerald Rathmell on the works 125cc Sprite with number 142, Jim Sandiford on a 250 Bultaco 66, Paul England on a 125cc Dalesman, number 160, a young Nick Jefferies was number 75 on the ex factory Triumph Tiger Cub, next to the popular Stan Cordingley on a 250cc Bultaco, who finished in 8th place on 24 marks, riding number 76.

Notable absentees from the event included Alan ‘Sid’ Lampkin who was riding a 400cc Husqvarna at the Bucks Grand National down at Brill, whilst Malcom Rathmell and Martin Lampkin were riding their Moto-Cross bikes in a Craven club scramble. Several other top riders included Ian Haydon, Derek Adsett and Rob Edwards.  

John Hemingway and Scott Ellis were riding in the Clayton Trophy Trial in Wales.

On the Saturday, Dave Thorpe had a good steady ride losing three marks, Terry Wright on his Dalesman lost five on the slippery hill at Billown and Gordon Farley finished up losing nine including , in what for him,  must have been a disastrous day with a maximum at Poylvaaish and several dabs at the Arragon River.

On the Sunday, Dave Thorpe went pretty much to pieces losing thirteen marks whilst Gordon Farley had the best ride of the day losing four marks. Terry Wright suffered a five on the vicious sections at ‘Tholt-Y-Wil’, but he did retain his composure and nerve for the rest of the event including the ultra steep rock climb at Sartfell Park.

The final results of the trial were:

1st  Terry Wright  125cc Dalesman.  10 marks                  

2nd Gordon Farley  250cc Montesa.  13   

3rd Dave Thorpe  250cc Ossa.  16                            

4th Paul  England  125cc Dalesman.         17

5th Gerald Rathmell  125cc Sach Sprite.  20

6th Jim Sandiford  250cc Bultaco.              22

The team prize went to Wetherby ‘A’ which comprised Terry Wright, Gerald Rathmell and John ‘Killer’ Kendrew  (who finished in 9th place on 24 marks)

A fantastic result for the popular Yorkshireman Terry Wright giving the Dalesman concern possibly their first and only ‘National’ win .

Fair bet that it was a good party that night!

(Front cover of 1970 programme by kind permission IOM Centre ACU)

BKS Remembered

Fifty years ago, Barry Kefford built and rode a lightweight sidecar outfit which spawned many sidecars to be produced for the chairmen of trials. The BKS chair was the piece of kit to have in the 1970s.

Here are two photos supplied by Barry’s passenger of the era, Geoff Bridgwater who is a Trials Guru website reader.

Taken at the Beggar’s Roost trial in 1970 in which they won the sidecar class on gtheir BSA Victor powered outfit with the innovative narrow, light weight sidecar and the 1969 trial at Hawkstone Park.

Factory AJS comes up for sale

Words: Trials Guru & Ben Butterworth

Photos: Jack Butterworth

A unique opportunity has arisen to purchase a true ex-factory AJS from the late 1950s!

Jackson 1957 SSDT Kinlochrannoch
Gordon Jackson pilots TLP686 in the 1957 SSDT on ‘Kinloch Rannoch’

The machine once the issue of former British Expert and ACU Star rider, Gordon L. Jackson, registered in 1957 by Associated Motor Cycles as TLP686, a 347cc AJS 16C.


The machine was ridden by Jackson in the 1957 British Experts trial and Scottish Six Days. The vendor has written confirmation from Gordon personally of the machines authenticity.


Lancashire’s Ben Butterworth is handling the sale for a close family friend who has owned the AJS for many years.

Ben said: “I’ve been asked to help with the sale of the Ex-works trials AJS 350 which was Gordon Jackson’s machine, the owner is open to sensible offers and would consider a part exchange.

Loads of history, letters from Gordon himself stating it was his bike, it is road registered, has the correct engine and frame numbers. This was the bike which won The British Experts Trial 1957, he also rode the SSDT on this machine.

The bike runs and rides very well, I’ve been lucky enough to have a ride on it myself after my Grandad has worked on it for the last two weeks, making sure it runs and polished it up for sale.”



The AJS has been put up for sale as the current owner stated to Trials Guru that “I’m not getting any younger and will never use it so I’d like it to go to somebody who would appreciate it for what it is with the history.”

The ex-factory machine is expected to fetch a high price and it has generated significant interest by both private collectors and museums.

Trials Guru’s John Moffat a enthusiast of the marque added: “This is indeed a unique opportunity to own a piece of SSDT, AJS and British Trials history that doesn’t happen very often.”


John Shirt and Gas Gas are back

Words: Trials Guru

Photos courtesy: Gas Gas Motorcycles & John Shirt Motorcycles Ltd

For many years the UK importer for the Gas Gas brand of trials motorcycles, John R. Shirt has formed John Shirt Motorcycles Ltd to become an authorised Gas Gas UK dealer.

Previously Shirt supplied trials dealers the length and breadth of the British isles with Gas Gas trials machines, but following the take-over of the Spanish brand by the Austrian based KTM organisation, matters have now changed dramatically.

KTM tested the trials market back in 1975, when they built a small number of prototype KTM trials machines and engaged Austrian Walther Luft and German Felix Krahnstover as development riders. Shortly after, the company decided to end the project and concentrate on development and production of both motocross and enduro machines.

John Shirt told Trials Guru: “I am excited by my new venture, Gas Gas had real financial problems since 2015, but now that the KTM organisation is fully in charge, matters have been resolved and now I am trading as an authorised Gas Gas dealer, selling bikes direct to the trials buying public at large. As an authorised dealer, we at John Shirt Motorcycles Ltd interface direct with the manufacturer, there is no official UK concessionaire any longer. I was very keen to continue with the brand which I have been loyal to for 30 years. I am looking forward to engaging with direct customers, many of whom I know are similarly loyal to the Gas Gas brand. I have already a team of great people at JSM raring to go.”

For more information, have a look at John Shirt’s official website: HERE

Photos of the new GAS GAS trials model:

Gas Gas 1

Gas Gas 2

Gas Gas 3

Gas Gas 4

Gas Gas 5

Gas Gas 6

Gas Gas 7

Gas Gas 8

Gas Gas 9

Gas Gas 10