Symphony for the Devil / 2020
To follow the AJS Stormer story, ‘The Commando, the Cobra and the Mongrel’ I was fortunate enough to bring together a small group of people, they or their fathers, were involved with the design and development of argueably the best British two-stroke engine ever built, ‘The Starmaker’.
Fifty years ago in 1970, AJS won, first and second place in the British Motocross Championship with this machine, ridden by Malcolm Davis and Andy Roberton, using the decendant of this engine, the ‘Stormer’, this article may also introduce you to several machines that you have not seen before.
Its ancestry lies with Villiers, which including AMC was taken over by Manganese Bronze, which in turn would become Norton Villiers, all during the time that the AJS Stormer, went through its development program.
So the AJS Stormer’s birth was quite difficult, but if you take the time and combine the story of the Starmaker and the Stormer, you come up with something quite extraordinary, something we should all be very proud of, so lets start at the beginning, the swinging Sixties.
A motorcycle design starts its life, as an idea in a person’s head, at some point that person starts sharpening their pencils; they don’t know the impact their design may have on the world of motorcycling but occasionally something very special emerges.
We invited one such composer, our ‘Keith Richards’, a motorcycle visionary, to our celebration, 50 years on.
John E Favill. A few words from a true Gentleman.
Thank you for inviting me to join this project. I enjoyed reading your history of the AJS Stormer, which brought back many memories. I now live in the US in Wisconsin, having come to work for Harley-Davidson on their Evolution Engine and Transmission, in 1979.
Well retired I am now in my 88th year.
John, how did your career start?
As an apprenticed, to Henry Meadows Ltd of Wolverhampton, a maker of internal combustion engines and gearboxes, in 1950.
I first met Bernard Hooper, when I started working for Villiers Engineering, along Villiers Street, in Wolverhampton; of course this was also the original hometown of A J Stevens.
Bernard Hooper began working for Villiers Engineering in 1958. He was an acknowledged expert on the design of two-stroke engines.
Early in his career he had met and worked with Hermann Meier, from this association, Bernard had gained substantive know-how of two-stroke engine design.
A little background, in 1898 John Marston, the owner of a small tin plate and Japaning manufacturing company, decided he wanted to buy a bicycle, but he found because he was a small man his legs were too short to reach the pedals.
The foreman of his tin plate shop, offered to make him a bicycle, of the appropriate size and his offer was accepted. The japanned black finish, with gold lining, of the resulting bicycle made it gleam in the sunlight, leading to the name Sunbeam Cob, this beautiful looking prototype suggested to John Marston, that it would be more profitable to make bicycles, than continue to just tin plate products.
One difficulty was the supply of pedals, so John Marston sent his son Charles to Pratt and Whitney in the US, to purchase machine tools to make pedals. Buildings were purchased in Villiers Street in Wolverhampton and the Villiers Company was formed, making bicycle pedals. Soon it was realised that production of pedals, was greater than the Sunbeam bicycles would need, so other bicycle manufacturers became customers.
The next step was for Villiers to make free wheels, for bicycles and over the years, production of these free wheels reached the point, soon after WWII, that the production rate exceeded 80,000 per week.
Then came another important turning point for the Villiers Company, in 1912, Frank Farrer began to work for the company, he persuaded Charles Marston that there was a market for engines, to power motorcycles.
The first motorcycle engine was produced in 1912 and it was a four-stoke, then in 1913, the first two-stoke engine was produced.
Original drawings for the Starmaker engine / 1962
It was at this time that it was decided that Villiers, being closely associated with the Sunbeam Motorcycle Company, should not produce motorcycles, but separate and concentrate upon supplying engines for companies making motorcycles, and also for products that required engine power.
The Villiers Company followed this policy even after the Sunbeam Company was sold.
In 1959 I was offered employment at Villiers, to take responsibility for the design of gearboxes and transmissions for the Company.
How did your work together on the Starmaker engine start.
After a few projects Bernard and I found we worked very well together and in 1961 we were asked to design a new engine and transmission, which was to became the Starmaker. Bernard concentrated on the engine and I designed the primary drive and gearbox.
The first thing I found, was I could not comfortably pull the clutch on the machines then using the Villiers engines, so I immediately began my research for a solution. On a small car made in Germany, with the memorable name, Goggomobil, they used a clutch made by the Hausserman Company, which used a diaphragm spring that reduced the hand effort, but increased the pressure to the clutch plates.
At the time there was a move to remove the use of asbestos and this fact plus the high pressure of the diaphragm spring to the clutch plates, allowed me to use friction plates using powdered metal surfaces, with its much lower coefficient of friction compared with asbestos based materials.
Original drawing for the Starmaker Road Race engine / 1962
I had been invited to join Villiers because I had gained knowledge of gear engineering taught by an English expert, H.E. Merritt.
The power that Bernard’s new engine promised made it obvious, that a totally new gearbox was necessary, so this was a challenge I very much enjoyed.
What support did you and Bernard receive from Villiers at that time?
Both Bernard and I had our own drawing boards and work areas in our office; also we were supported by the Villers Design Team, which were a group of talented designer/draftsmen, so we had all the help we needed. We also had, in-house pattern makers, they had the expertise to produce prototype castings, an excellent machine shop and then the prototype testing technicians. Plus, expert advice on choice of material specification, heat treatment, etc. Numerous individuals were involved; you can’t do it alone, they are all necessary, if a design of competition specification is to be successful.
Bernard and I enjoyed our work on the Starmaker project, it was also very successful, our friendship grew, so in 1965 when we had completed our work, we decided to leave Villiers and form a design consultancy of our own, so that we could patent our own engine designs they would then, for the first time belong to us.
But things didn’t go as planned?
No, at this moment, the Villiers Company was taken over by Manganese Bronze, headed by Denis Poore and unknown to us, Monty Denley of Cotton Motorcycles, told Denis Poore, “If you wanted a future using Villiers engines, you will need to employ, Bernard Hooper and John Favill”.
Following a phone call from Denis Poore, Bernard and I returned to Villiers, to form an Advanced Design Department, working on our patents, but again plans quickly changed.
The company was expanded further, as Denis Poore took over the AMC motorcycle group, and that included AJS, Matchless and Norton Motorcycles. Poore told us that the company desperately needed a new Motorcycle. So Bernard and I dropped our design and patent work and formed a new design group, which included the existing Villiers designers, plus several new engineers that we recruited.
Where did these changes lead?
The result of this work was the Norton Commando and the AJS Stormer.
John Favill’s original sketch for the six-speed gear-box / 1962
What is it like when you start with an idea on a piece of paper, and finally you produce machines like these.
When one eventually handles parts that have been made in accordance to one’s design and your ideas then pass all the development tests, and produce comments of approval from users, it is a feeling that I find difficult to describe. In a way I get a similar feeling looking back at my motorcycle career of being involved with the Villiers Starmaker, the AJS Stormer and the Norton Commando, it’s an amazing feeling.
What moments stand out, 50 years on?
Derek Minter was to me, one of the greats. He rode for Cotton and he did this for free, completely content with the race prize money, awarded when he won a race.
He came back after taking out the Starmaker for the first time and asked for more gears, my response, was, I immediatley got to work, and designed him the smoothest six-speed gearbox I possibly could.
What about the Villiers Special, and the Starmaker AJS?
Peter Inchley, who I knew very well, took the six-speed gearbox, in his Villiers Special, to a third place finish in the 250cc IOM TT, it was all incredibly satisfying.
This was the preliminary work for the Starmaker AJS, and the first time for 16 years that a British machine had finished in the first three, and the first time a single cylinder machine had lapped the TT course at an average speed of over 90 mph. (91.43 mph), and this record still stands today.
John Favill’s six-speed gear-box / 1962
The most treasured remark ever made to me about my six-speed gearbox was at one time I was at the IOM.
I met Tommy Robb, who had ridden a bike with a Starmaker and with a six-speed box. He told me the gearbox was the best he had ever ridden.
The last question I would like to ask John, why the central position of the exhaust port, when most machines at the time were constructed with a single down tube frame?
Bernard followed his design know how, on two strokes, by putting the intake port to the rear, so the carb and air filter could be located below the seat. Then he placed the two transfer ports, sufficiently large, each side of the intake, with the fresh charge from the pressured crankcase directed towards the far wall, this scavenged the exhaust gas up, and into the exhaust port which was located central, at the front of the cylinder.
Peter Inchley / Starmaker AJS / Debut
Another point, which highlights Bernard’s objective for performance above all else, was the introduction of two carbs, with a control box, so that one carb opened fully, before the second one began to open.
Dynamometer testing demonstrated that the single carb at low R.P.M gave high torque, and then with the second carb open, the output increased.
Full of confidence, the twin carb set up was introduced but soon problems arose, because riders could not sense the effect that the dynamometer testing had shown, so the single carb layout became the norm.
Earlier Villiers single cylinder two-stroke engines, such as the 34A, had the exhaust port in the central position on the front of the engine.
Motorcycle frames, designed with a single front down tube, like Greeves and DOT, certainly had difficulty with the layout of there exhaust systems, but Cotton and DMW used twin front down tubes, the frame of the AJS Stormer followed there design, it’s a Villiers engine, but as you know, the frame decides the marque.
John, thank you very much for providing such an insight into those early years and providing us with such fabulous motorcycles.
Peter Inchley / Starmaker AJS / Debut
Peter Inchley, who worked for Villiers on the Starmaker project and Fluff Brown, who worked with him at Cotton would come together at Norton Villiers and create the new AJS motorcycles, the Starmaker AJS, the Road Racer and the Scrambler, the AJS Stormer.
The mechanical ‘Symphony’, of this story, is the Starmaker AJS, it was the outcome of two years intensive engine development and revolutionary thinking on frame design, the result being this outstanding 250cc Road Racer.
Starmaker AJS frame / 1967
The engine was a vastly improved 247cc Starmaker two-stroke single cylinder unit, which Peter Inchley, Norton Villiers development engineer and British 250cc Road Race Champion, had developed and raced over an 18 month period.
It developed 32 bhp at 8,400 rpm at the gearbox – a power output equivalent to a road speed of 120 mph, and he used it to lap the Isle of Man TT circuit, at an average speed of a fraction under 93 mph.
Redesigned transfer and exhaust porting, a new pattern piston and an entirely new exhaust system contributed to this increase in engine performance. In addition, the engine had a new race proven big-end assembly and a modified all-metal diaphragm-spring clutch, giving 50 per cent more capacity than the earlier versions.
The six-speed gearbox is identical to the prototypes that had stood up faultlessly to four years of race testing in many parts of the world.
“Cliff you may recall that in 1966, Peter on the prototype, finished in third place in the IOM TT this was, a modified Bultaco frame, for commercial fairness, powered by a Starmaker, ‘The Villiers Special’.”
“I had designed that six-speed gearbox for Derek Minter to use, in his Cotton Telstar, but Peter was to take it on and prove in ‘The Villiers Special’ that the Starmaker was the fastest 250cc single”.
“He was then to show that the Starmaker AJS, it was even faster than that, the only bike to beat it was the extraordinary, six-cylinder Honda 250cc, introduced for the first time that year”.
“At this stage it was the intention to produce 2,500 of these gearboxes, but in the end, due to unforeseen circumstances, only a fraction of that number were sold.” John Favill / 2020.
These gearboxes are now highly sought-after, only just over one hundred were ever produced.
Ken Sprayson designed the frame, and the design is similar to the AJS Stormer frame in as much as, it is also built around the idea of a large diameter backbone spine. Weighing only 15.5 lb, the all welded frame is immensely strong, its sound geometrical configuration, based on a 2.5 in diameter tubular backbone, ensured extreme rigidity.
The engine is cradled in twin small-diameter down tubes and the swinging arm rear suspension, is controlled by Girling adjustable oil-damped units. The lightweight teledraulic-type front forks were of Norton Villiers design and manufacture, as were the special lightweight hubs.
The standard fuel tank had a capacity of 2.75 gallons, but also housed in the frame beneath the riders seat is an additional fuel tank with a capacity of 1.75 gallons, an arrangement that also lowered the bikes centre of gravity.
The Starmaker AJS would have been supplied with a range of jets for the Amal GP carburettor and different sized rear-wheel sprockets, it was also available with an aerodynamically designed lightweight fairing, when fully equipped, it weighed only 198 lb.
Starmaker AJS frame / 1967
“There was an interesting artifact in the competition shop when I started working there”, reflects Frank Damp, who later went on to work for Boeing, in the US.
“A grid made up from masking tape was mounted on the wall, with inch markings from a felt-tip pen, I asked what it was, and my boss Peter Inchley’s assistant produced some photographs”.
“They showed the TT bike on an axle stand with Pete on the seat in a racing crouch. One of the pictures had a hand-drawn fairing on top of the image.”
“Apparently, they took side and front views, drew on a fairing shape, then produced some engineering drawings. These were taken to a local fibreglass firm to make up the fairing, which we then took out and tested on the track.“
Pete came in, “Wind tunnel?… We don’t need some stinking wind tunnel!… when I was coming down hill on the TT course, in a full crouch, going just about as fast as the 250cc would take me, I sat up to get a better look at the corner, and I got another 5mph!…”
Peter Inchley’s son, Graham, has now lovingly restored this extraordinary machine; he takes up its story.
I have returned the bike to its original 1967 livery, from the only clear picture that I have, of dad passing through Parliament Square in that years Lightweight IOM TT.
I was able to carefully cut back the paint and determine the perfect colour match.
Starmaker AJS / James Everett / 2020
When I received it, the bike had been altered with a square-section swinging arm, I removed this and an engineering genius, Dave Davis, built a beautiful original specification, replacement.
Fortunately the frame was straight and the engine miraculously, complete. I stripped it down and rebuilt it but I left the port timing set at, ‘Safe’.
When it came to starting, for the first time in many years, we were quite cautious, we had fitted it with a new Electrex ignition to give it the best chance and literally, on the first throw of the piston, it exploded into life.
In 1964 Derek Minter riding a works Cotton Telstar, which had gained John Favill’s six-speed gearbox, had taken the ACU Star. Minter, Inchley and Bill Ivy continued on into 1965, to notch up many more victories.
In 1966 Peter Inchley on his ‘Villiers Special’ accomplished an average speed of 91.43 mph for the 264-mile distance of the IOM, and no British-built ‘250’, had come anywhere close to lapping at that sort of speed, and none had come in the first three since 1950.
Essentially Norton Villiers then took over the project at this point, and decided to develop Peter Inchley’s machine and back him in the 1967 Lightweight IOM TT.
The two-stroke projects were then given the AJS name, these were after all, competition machines, and the frames were to be built around the backbone design.
Starmaker AJS / James Everett / 2020
For the TT model they retained the six-speed gearbox and planned a new engine.
But unfortunately at this time, 1967, Norton Villiers attention was taken up by the development of the Norton Commando, it was felt that the big four-stroke had the largest market potential, so the Starmaker unit that Peter Inchley had raced at Mallory Park, Snetterton and set the lap record for a 250cc at Brands Hatch, was used.
Inchley went on to average 92.89 mph, he was running second when he had to come in for fuel, he gassed up and flew out of the pits, he was now in fifth place but owing to a serious error by the fuel company, the engine seized after about 5-miles. When Peter had stopped for fuel, his tank had been refilled with neat petrol, bringing his race and the project to an abrupt end.
Nevertheless, there was little doubt in anyones mind; the AJS single-cylinder was as far advanced as any of the equivalent continental two-strokes.
I certainly enjoyed the restoration, and I sincerely hope James enjoys the finished bike, in whatever way he chooses; I can always tweek the engine. Graham Inchley / 2020.
So who is James, who would choose to have this thoroughbred rebuilt?
Well it turns out, there’s a book about him, ‘Rocker to Racer’, Reg Everett had brought the bike to Graham Inchley, the person who had persuaded Greeves to part with one of their engines and proceeded to create the Greeves Silverstone.
A ‘Ton-up Boy’ who took it to the track and successfully competed against the likes of Mike Hailwood, Phil Read and Bill Ivy, he had followed in Peter Inchley’s footsteps, and he clearly, held this machine in very high regard.
Starmaker AJS / James Everett / Reg’s Grandson / 2020
Freddie Mayes, our ‘Mick Jagger’, started working for Norton Villiers on the 1st of January 1967; he was the British Motocross Champion, after winning the series for Greeves the previous year. His brief was to develop the new AJS Scrambler, which was to become, the AJS Stormer.
A Metisse frame was chosen for the initial machines, this, as with the Starmaker AJS prototype, “The Villiers Special”, was for reasons of commercial fairness, it kept the project neutral for the benefit of other manufactures, using Villiers Starmaker engines, at the time.
Freddie Mayes / Greeves / 1966
I asked Freddie about these first days?
“I was happy with the choice of frame, I had discussed this with my initial contacts at NV, who were Peter Inchley and Ron Price”.
“For the first engine, Peter and I built one using the cylinder from the 1966 TT bike, which we thought would provide us with a reliable starting point. The Stormer truly was setting out as a direct decendent of the Road Racer, albeit with the ports heavily modified, with fibreglass!”
As reported in the MCN on the 11th January, “Freddie Mayes will contest this year’s 250cc World Motocross Championships with the full backing of Norton Villiers. He signed a 12-month contract last week and intially he will race the ‘Villiers Metisse Special’.
It was NV public relations officer Ron Price who broke the news of the Norton Villiers tie-up with the Rickman brothers.
Greg Radley’s / Villiers Metisse / 2020
“The Rickman’s have been very co-operative, working with Freddie they have pulled out, all the stops, to build him two machines with the new Starmaker scrambler engine. The machines were completed at the weekend and will be tested at Hawkstone Park this week”.
Freddie added, “Yes, my first race was straight in at the deep end, at the BBC Grandstand meeting. It was high pressure, but the Rickman brothers and Norton Villiers managed to completed the first competition ready machine, in time for testing, and we just made it, to its debut, at the TV scramble that Saturday, at Cuerdon Park, Preston, on the 14th January”.
The Bultaco Metisse frame had to be modified to take the Villiers unit, the most difficult bit being the bottom frame rail, which was gapped, to make way for the gear lever. The huge expansion chamber was housed, but would be tucked away a bit more, later on.
Freddie Mayes / Cuerdon Park / 1967
The race went well, with no real trouble, considering this was only after two weeks, Freddie was in third spot in the 250cc race, when he unfortunatly missed a gear on the hill.
Peter Inchley said “It is giving as much as anything out there”, this statement being backed up by the fact that Freddie, in practice found he was always gaining on Bickers on the straight.
Freddie continued, “I was disappointed to finish just outside the points in 7th, I think it was my fault for trying to over rev that engine, when it had really been set up, to pull in mid-range.
“At first we had a very long tail pipe to the exhaust system, to make it pull, eventually we cut the tailpipe in half, which helped it rev more, this was more like what I had been looking for, it suited me much better”.
“At the next round of the BBC event, it was brilliant”.
“I led almost the whole 250cc race, it again was going really well, and then I, stupidly, hit a hidden tree root two laps from the end”.
“So the bike was already performing quite well, I felt it was as good as any of the British competition, but not quite up to the Husky or CZ standard, yet”.
But Freddie was right, the break through wasn’t far off, the bike had come on a long way.
“The works Villiers Metisse has had its first taste of victory”, wrote John Brown, MCN.
“This encouraging step forward for its developers came on Sunday, 22nd February, when Fred Mayes forced his way through the Somerset Mudbath at Stearts Hill Farm, Sparkford, to win the last race”.
Freddie Mayes / Somerset Mudbath / 1967
“He was backed up in fine style in this race and throughout the afternoon by team mate Andy Roberton who claimed two seconds, one third and fourth placings”.
“Although the sun shone through most of the meeting, the previous day’s rain had turned the course into a mass of thick, sticky mud”.
“Alterations had to be made after the practice session when most riders found it impossible to climb a steep hill shortly after the start”.
“All eyes were on the young Norton Villiers signing, Andy Roberton, he gradually wore down the opposition and after securing second place on lap four, he actually started to gain on the leader and wasn’t far behind at the finish”.
Experts Only; 1. Freddie Mayes (Villier Metisse) 2. Andy Roberton (Villiers Metisse) 3. Malcolm Davis (Greeves)
Bryan Goss and Freddie Mayes / 1967
“Local man Bryan Goss was the star of the show but Freddie was the one making the news”.
“Coming home 1st in the Experts only race ahead of his new teammate Andy Roberton and Greeves mounted Malcolm Davis”.
This was an exceptional achievement for just two months work. Andy had won the Tweseldown Championship in early February, at the age of eighteen on his own CZ. A week later Norton Villiers signed him up as their second development rider, both he and Mayes had raced with Fluff Brown before, as Cotton works riders.
MCN 6th June 1966, “Fluff Brown introduced newly- signed Cotton works rider Andy Roberton to the Dartmouth club on Sunday. Just how good Roberton is became increasingly evident during the course of the meeting, for he won three great races against very stiff opposition”.
Then for the opening round of the British Championships, 5th March, Chard, Freddie achieved a very decent 3rd place behind Alan Clough on his Husqvarna, and Dave Bickers on his CZ.
Freddie takes up the story, ”My first GP was the Spanish GP in March, so I was away, I came in 9th overall, which I was quite happy with”.
“I honestly can’t remember for sure, but I think we took up designing the new Norton Villiers frame on my return, in April or May. The first part of this was, Andy and I, being asked which bike we thought was the best handling 250cc at that time”.
“We both answered, the twin-port 250cc CZ”.
“So a CZ was bought, and measured up at the factory in Wolverhampton, and a frame was built”.
“The engineers obviously had their own ideas, because the first frame we tested had a wheelbase some two or three inches longer than the CZ”.
In 1964 the 250 World Championships were won by Joel Robert on the CZ single down tube twin-port CZ, he was followed in 1965 by the Russian, Viktor Arbekov, this was a dream machine.
Twin-port CZ250 / 1965
Andy No23, still entered as riding a CZ, had made his debut on the Villiers Metisse at Naish Hill on the 11th February, in front of the BBC TV cameras, where he finished an excellent 4th place in his first 250cc Grandstand Trophy race.
Andy Roberton No23 / Villiers Metisse / Naish Hill 1967
Fluff Brown, who had earlier moved from Cotton to work for NV, recalls that despite such a promising start, it wasn’t a fairy tale relationship.
“Andy didn’t get on so well with the Metisse framed bike and he was disappointed with his results”.
“So I built up a bike using the Y4 engine in a Cotton frame, and he soon returned to his winning ways”.
Andy unveiled the new Villiers Cotton prototype, on the 30th May at Farleigh Castle in the Maybug Scramble, riding No38, and he immediately liked this machine.By September the Villiers Cotton, was put into production as the Cotton Cossack, as announced in that months Motorcycle Sport.
“The prototype 247cc Villiers Cotton scrambler ridden by Andy Roberton during development of the latest Villiers Starmaker MkII engine, has now gone into production, as the Cotton Cossack”.
Peter Inchley and Freddie Mayes / 1967
“It has a single-down-tube frame with top and front-down members of 1 5/8 in tubing and a rear assembly of 7/8 in diameter tubes. Either the Ceriani or Metal Profile moto-cross front forks can be supplied, pivoted on Timken taper-roller steering-head bearings. The Cossack’s high-level exhaust system built to Norton Villiers specification has a lengthy tail pipe”.
Freddie continued, “I must admit, the first prototype handled brilliantly over the bumps at Hawkstone, but I found it wouldn’t go round corners, especially the left hander coming down from the hill”.
“So then, back to the drawing board”.
Andy Roberton (Centre) / Villiers Metisse / Somerset Mudbath / 1967
“From then on I was pretty much away doing the GP’s, for weeks at a time, so Andy did a fair bit of the testing on the new frame”.
I never rode one at a meeting until September, when I was back from the circus, by which time Andy had returned to ride for CZ”.
In July, Roberton, No45, had taken the Villiers Cotton to Wakes Colne for his GP debut, and put in an amazing proformance, at one point he was fourth behind Joel Robert, Torsten Hallman and Victor Arbekov, he managed to finally earn a championship point, by coming an outstanding sixth overall.
Villiers Metisse / Rickman Brothers / 1967
Ian Berry – ‘Out Front’, Mayes rode well in the GP’s in 1967, gaining valuable experience, though he was plagued by mechanical problems all season.
Typical of this was his bad luck at the Wakes Colne meeting, when an oiled plug eliminated him in the first race and he was also forced to pull out of the second race, mid-way through, whilst well placed.
Freddie Mayes, “I did all twelve rounds of the GP’s, my best result was 7th overall in the Dutch round, and a 6th in one leg in Poland. My most disappointing GP was the British round when I had a plug oil up on the start line in the first leg and then ignition failure in the 2nd”.
“I never had any complaints with the Metisse framed Starmaker though, but I know Andy prefered the Cotton framed machine, that he continued to used for quite a while”.
“I can’t really remember when exactly Fluff joined NV, I don’t think he was there at the very beginning, but with him the next frame was pretty much ‘on the money’ and not too much was altered after that”.
Andy rolled out this second prototype, No47, on the 30th July 1967 at Farleigh Castle, in the programme it was listed that he was riding, a Cotton. By September 1967 the bike was given the ‘AJS’ name and at Hawkstone Park, Mayes took the Midland Championship to give it, a winning debut.
Ian Berry – ‘Out Front’, He also lead the Brian Stonebridge Memorial race at the same meeting, until a stray rock hit the timing cover causing the AJS to splutter to a stop.
This did little to help him in his struggle to retain his British title, but had Lady Luck smiled more kindly on him, Fred believes he might well have done just that.
In the final race of the 250 British Championship at Cadwell Park in October, he finished 5th and was edged out of runner-up spot in the Championship by Dave Bickers, who took the tie breaker only by virtue of winning the previous Hintlesham Park round.
Freddie Mayes, “In the British Championship I scored points in every round, and finished equal 2nd in the standings, not too bad for a new development machine”.
“I must have raced the Metisse framed machine for the first three rounds, and the AJS frame for the last two”.
Villiers Metisse / Cuerdon Park / 14th January 1967
Maybug Trophy Scramble 1967 / daveriley.weebly.com
Freddie Mayes No8 / Norton Villiers / Farleigh Castle / May 1967
Andy Roberton No38 / Villiers Cotton / Farleigh Castle / May 1967
Andy Roberton No45 / Villiers Cotton / Wakes Colne / May 1967
Andy Roberton No47 / Cotton / Farleigh Castle / July 1967
International GP Great Britian July 1967 / daveriley.weebly.com
Andy Roberton No47 / Cotton / Farleigh Castle / July 1967
Freddie Mayes, “By the time I left Norton Villiers, in October, I think the AJS Y4 Scrambler was handling really well, it was on par with any other 250 out there at the time. Peter was always in charge of the engine development, and apart from those few ignition problems the engine and gearboxes were always good”.
Freddie, thank you for sharing with us the story of your year at Norton Villiers, the result has given me a machine I have enjoyed for over forty years, and it’s still going strong today.
So again thank you for providing some very insightful details on the development path you and the team all followed.
“You’re very welcome, I had a very enjoyable time at Norton Villiers, and as an example of this, I always got on very well with Peter, and at my wedding in that September, he was my Best Man”.
“And here Cliff, is a photo of me on the AJS Prototype at Cadwell Park 1967, scoring as far as I know, the first British Championship points for the AJS two-stroke”.
Freddie Mayes 2020
Freddie had completed his task at AJS and for the next season he took on a ride with Montesa, but before that, Dave Bickers lent him his machine.
His twin-port CZ, Freddie took this to Canada Heights for a test, and won the Grandstand Trophy in October.
He rated this machine as his favourite of all-time.
So finally, as a true gauge of how well the AJS development team and Freddie, had really done. In competition, only Alan Clough had beaten Freddie, on his Husqvarna, but Freddie had just equalled, Dave Bickers on that very same CZ world-beater.
The next year, in a full season of Championship racing, the AJS beat them both, and even Don Rickman on his Bultaco Metisse, to take the title for the first time since 1954, with the then named, AJS Stormer.
AJS Scrambler Motorcycle Sport, August 1968
Norton Villiers have secured the future of the AJS project by establishing the AJS Motor Cycle Division as an autonomous manufacturing and trading unit. The Division will operate from Woolwich until the autumn, when a move is scheduled to premises in Andover, Hampshire.
So also, the AJS Stormer project roots be traced back to the old AMC plant, in Woolwich.
“I was a little dis-appointed, when I opened my August copy to find your piece on the Norton Villiers, as the machine featured, was purely a “one off” experimental device, which was used in only one meeting and then withdrawn”.
“This was bad enough in itself, but extra salt was rubbed in the wound when I realised that it is some five months since this machine was made ready for you, for testing!”
Malcolm Davis No16 / Farleigh Castle / May 1968 / EricMiles
This was the so called Norton Villiers scrambler, being taken to that “one off” meeting at Farleigh Castle.
Motorcycle Sport continued: Development is also nearing completion of the new 360cc scrambles engine, production of which was planned before the end of the year. Together with the Engine Division at Wolverhampton, and the Norton Matchless Motor Cycle Division at Woolwich, overall responsibility for the AJS Motor Cycle Division was put in the hands of Philip Sellars, who was appointed managing director of Norton Villiers Ltd in December 1967.
Malcolm Davis No37 / AJS Scrambler (note front forks) / Farleigh Castle / 1968
Heading the list of priorities of the new Division is the production of the 250cc scrambles machine, which is now in the final stages of testing by the three works riders, Malcolm Davis, Chris Horsfield and Dick Clayton. The first models are expected to be available later in the year. This machine, in orange, black and chrome finish, will be equipped with the new AJS forks and hubs.
And just in case we’re still hazy about the AJS Scrambler, Mr Inchley enclosed this photograph.
I think this is the first published photograph of the completed machine.
Motorcycle Sport, August 1968
May Bug Scramble 1968 / daveriley.weebly.com
Malcolm Davis No37 / AJS Scrambler / Farleigh Castle / 1968
Motorcycle Mechanics. Engine Analysis, July 1970.
Chris Horsfield / AJS Y4 Stormer (Earliest colour photo) / EricMiles
The claim of being the most developed scrambler in the world sounds a bit risky. But applied to the works Y4, it could well be true.
A quick look at the competition results will confirm this; from racing the prototype in 1967, AJS have now won the British 250 Championship and Malcolm Davis proved that the machine, now known as the Stormer, can easily hold its own at the International level.
The development of the complete machine, shown here with Chris Horsfield at Doddington Park, 1968, powered by a derivative of the Starmaker has been in competitions and in full view of a critical public.
All the issues found during this period have been rectified and now AJS are confident that they have a winner. Not one, but rather two, as they have produced a 370cc version, the Y5.
Replicas of these remarkable machines are now available generally and with a good dealer network, AJS are aiming to change from ”most highly developed” to “most highly successful”.
Keith Browning’s / Starmaker AJS
Stormer Engine Analysis No13.
(This is a Historical Document, seek up to date information about your engine).
This AJS motor is simple, even for a piston-ported two-stroke and embodies a lot of ingenious features. Work on the motor couldn’t be easier but nevertheless a couple of special tools are needed and there are one or two points where you have to be careful or there could be disastrous results.
The clutch, with its sintered-bronze friction facing and diaphragm spring, is a most advanced and robust unit. Two circlips are used, one to locate the centre and one to retain the spring. The small one in the centre has to fit precisely in its groove and so a new one should be fitted each stripdown. It should also be fitted with a good pair of circlip pliers to avoid any distortion.
The large circlip holding the spring has to carry quite a load and it is a risky business trying to dismantle the clutch without the right spring compressor. On reassembly, tap the ends of the circlip to ensure that it is well and truly in its groove around the clutch housing.
The crankshaft has to be set up quite accurately. End-float, is easily controlled by shims, but the shaft itself has to run to within one thou. This obviously needs a dial gauge, to get this kind of accuracy, so if you haven’t got one, don’t disturb the shaft!
This brings us to another point; a strap-wrench should be used to lock the flywheel when tightening the nut. Don’t scotch the sprocket on the other side of the shaft or you will twist the crank out of true. The tightening torque on the nut should be 90 lb.ft. The works mechanics put a trace of Loctite EV on the crankshaft taper when assembling motors. It isn’t essential, but it’s a good idea to follow their practice.
As the cylinder barrel has very large ports, there is a risk of a piston ring jumping into the ports when the barrel is being fitted. To avoid this, remove the cylinder head studs from the crankcase, and turn the cylinder barrel roughly 45 degrees to one side. This ensures that the ends of the rings don’t go over any ports. When it comes to fitting the studs, it is not always possible to tell how far they have been screwed into the case. With this problem in mind, one of the holes has been made open at the front of the crankcase. The procedure is to screw one of the studs into this hole until there is one thread protruding. Then screw in the others until level with the first one. There is no primary chain adjustment provided as such. When stripping the motor, check the chain tension, if slack, it can be tightened on reassembly by adding gaskets between the engine and gearbox. About four is the recommended maximum.
Lubrication is quite straightforward, except that AJS recommend a castor-based oil for the engine. As this is mixed with petrol, it is worthwhile to make sure that the mixture is thoroughly shaken up before starting the engine, especially if it has been standing for sometime. Either a castor or a mineral oil maybe used in the gearbox, but once you make your choice, stick to it. Remember that castor-based oils must not be mixed with mineral grades. A mineral oil is recommended for the primary chaincase.
AJS Chinditz / Terry Pickering
The Stormer went through further development after the 250, there followed the 370 and 410, and but this wasn’t the end, this year at the Classic Dirt Bike show, an enthusiast called Terry Pickering put quite an amazing machine on display, you could say, the ‘Charlie Watts’ of our band. The last time it was seen, was almost certainly when it was being ridden by one of its developers, over 45 years ago, at a televised motocross meeting at Cadwell Park, and this is what he had to say after his days racing;
“This is the first time I have raced it, but it will be the machine of the year in 1973”.
Vic Eastwood had just gone out and won, both the Castrol and World of Sport finals, on his stealthy newcomer, and he hadn’t just beaten anyone or just anything,
Castrol Trophy Final 1972. World of Sport Trophy Final 1972.
V Eastwood (500 AJS) V Eastwood (500 AJS)
V Allan (400 Bultaco) B Wade (400 Husqvarna
B Wade (400 Husqvarna) V Allan (400 Bultaco)
J Banks (380 CZ) B Goss (400 Maic
R Wright (500 CCM) J Banks (400 CZ)
D Nicoll (380 Greeves) B Wright (500 CCM)
When you look at these results, you know something special had just taken place.
So what was this machine?
Terry told me, “I have a copy of the design drawings which calls it the ‘Chinditz’. I also have a second frame, and all the casting moulds, boxes and boxes of spares, so I could almost make a second one, I was amazed that so many parts had survived”.
Vic Eastwood, was and is one of the most respected names in British motocross, he rejoined AJS in February 1971, as a development engineer and works rider.
He said at the time, “My job is not necessarily to win races, but to develop the new AJS 410 Grand Prix, through to production.”
His surprise move came, only weeks after the departure of Peter Inchley and their British riders, Andy Roberton, who had gone to ride for BSA, and Malcolm Davis, who had returned to Bultaco, and these two were at the peak of their careers, they had just won, first and second place in the 250 British Motocross Championships of 1970, on their 250cc AJS Stormer’s.
AJS Stormer 410 / Vic Eastwood / Halstead 1971
At this time Vic Eastwood, was 29, and had been racing works Husqvarnas, as a professional freelance scrambler, for three years. He had won huge admiration for his fight back from a crippling injury in 1968, when he smashed his kneecap and had to quit his permanent job, with the AMC factory team at Plumstead.
By November 1971, Vic had the production version of the AJS 410 Stormer, ready for its final shakedown in Irvine, California, at Saddlleback Mountain; this was its preparation for its public review, in the UK, in January 1972. The 410’s actual capacity is 406cc, and the engine is derived from the original double British Championship winning 250cc machine.
Vic, at that US meeting, blitzed all comers in the CMC’s 500 Experts, he cruised around the Saddleback course with an inspired Dave Smith dancing in his shadow, and in all three motos, Eastwood had won the drag race to the top of the start hill.
In the first moto his quick lead allowed him to spend the first couple of laps learning the berms and ruts created by the earlier 250’s in their ten races. Morris Malone on his AJS 370cc Stormer, held second place, with Smith just keeping up in third.
Then, Smith, Open Class winner at the previous weeks CMC, made his move on his Maico during the third lap. He shot past Malone and set his sights on Eastwood’s thirty-yard advantage. On the last lap Smith put on a super burst of speed and almost caught the Stormer 410 but Dave’s challenge didn’t catch Eastwood off-guard and the AJS Ace countered by teaching Smith the art of the 180-degree turn.
The second moto saw Eastwood slide gracefully through the first corner into a precarious lead. Smith was hot on his heels with his Maico flat out, and Feet’s wasn’t far behind on his hungry Husky.
Dave managed to pass Eastwood as they headed for the Liveoak Grove Switchback, and gained about a ten-yard lead over the Englishman as they left the bend.
After two unsuccessful chess moves, Eastwoods new Ajay lived up to its name, and stormed past Smith after hitting the throttle early, out of the bend the next time round, Smiths Maico had nothing left and Vic drove the lead home.
He then encored the first two races, in the final, his machine leaving the others, humbled, by its superiority, combined with Eastwoods masterful riding.
He had shown the Americans, “how”, and the general consensus of opinion at the end, was that this brilliant machine, “Was just a tad, faster…. “
The 250 Stormer, has a bore and stroke dimension of 68mm x 68mm. The 370 Stormer, the first 500cc Class model, obtained its capacity by being bored out to 83mm.
This bore size was retained, but the stroke was lengthened to 74.5mm for the 410, motocross development at this stage was very rapid, and as you can see from this experience at Saddleback, the 410, was already needed to replace the 370 but even then Vic Eastwood was thinking ahead, he didn’t stand still for very long.
Vic Eastwood / AJS Chinditz / 1973
But the ‘Chinditz’, is something very different, this is ‘the Son of Stormer’.
The secret invader from AJS, which terrorised Cadwell Park in 1972, when Vic Eastwood bolted from the gloom and scored a super silent double. Was an all-new British “500” and was the final prototype of a planned, production scrambler.
Eagle eyed viewers, who had watched Eastwood win those two events, may have noticed that his machine had a left foot, gear change. Even the great Malcolm Davis on his 400 Bultaco, could only have been enviouse, as he watched this new Ajay, vanish into the mist.
AJS Chinditz / Left-foot gear-change
Other innovations, Malcolm may have noticed, were the rubber-mountings for the new power unit, very similar to the Norton Commando, and the huge new stealth silencer, with flexible bellows, on the same side as the gear lever and kick-start.
This prototype had quite obviously been based on the 410 Stormer, but it started life almost by accident. The ex-Plumstead racer had been ‘playing around” with a new idea for a frame, when he discovered that Graham Evans, was also playing around with a big engine.
The two naturally got together, and as the plans went beyond the playing around stage, Martin Jackson was roped in to draft out the new designs and the magician Robin Clews welded it together. Suddenly Norton Villiers had got them selves a new racer.
Basil Knight, “If I’m correct, then this was at the race shop at Thruxton, about 25 yards from where I’m sitting now. The name Robin Clews is mentioned as being the one who welded the frame. I believe it is actually Robin Clist who did all the welding in the race shop, and subsequently, the for John Player Norton team”.
“It’s always interesting to see and hear about a bit of your own past. I was asked one day in about 1971 to look into the radial fit of the porting for this barrel, and the person who asked me was Peter Inchley. Pete also put together the exhaust system as that was one of his forte’s”.
“The bike was constructed at the race shop at Thruxton and Vic Eastwood test rode it around the field outside the workshop. I’m sure it only needed a 4 speed gearbox because it was so torquey….”.
“Those were the days, and that was in 1971, just before we became the John Player Norton Team”.
The original motor was a bored and stroked 410, using the Stormer gearbox. The unit vibrated, an issue that Fluff Brown said “diminished the competitiveness of the 410” it caused rider fatigue, and so they decided to use a modified Isolastic set-up pinched from the Commando, to isolate the frame. This system was retained even though they eventually ended up with a completely new engine.
This motor was a conventional piston-ported two-stroke brought up to 500cc, which drives through a Stormer all-metal clutch and a Norton gearbox. One unusual feature is the type of chain used for the primary drive, where they’ve reverted to an inverted-tooth type.
This was because a triple row chain roller was necessary for reliability, but it was just too wide, and the inverted tooth design was the only way the drive could be made strong enough and compact enough. That is, without completely redesigning the whole transmission and using a gear drive.
They didn’t play around with reed valve induction for the simple reason that “they had more than enough power”. Vic explains, they were getting 47bhp, the new motor gives 39bhp, but it’s quicker. The power starts from tick-over upwards and runs on through the 7,000 rpm peak, to 8,000 rpm, the 410 gave out 35bhp.
There is so much low-down torque that they don’t need to change the exhaust systems to suit different courses and Vic added that the motor is more like a four-stroke as far as riding is concerned. The exhaust itself is an interesting point – inside the box is a series of tubes and chambers, which gave the expansion box effect, with a silencer in the end.
Vic added, we have a chap named John Favill working out of Wolverhampton, who is a wizard. He’s responsible for silencing the Nortons, and he’s also done a great job with the AJS, he originally built the Stormers excellent gearbox, and now the Stormer finally gets a left-foot gear-change, one of the features that held it back in the US, and the American’s have been screaming for…
At the moment we are running a system at 96 decibles, which is well within regulations but we can also run it at 90 decibles without any real loss of power. In another effort to keep the level of noise down, the decompressor was designed to blow out into the exhaust down pipe.
Carburation and ignition were looked after by a Spanish Femes system with a large Concentric Amal carburetor and a redesigned air filter, which again keeps the noise in, while keeping the dirt out.
John Favill was again the gearbox king, and provided the machine with a four speed box, but with the wide spread of power available, Vic said he only needed three, and on some courses he got away with using only two.
One of the reasons for this he said was the lightweight of the machine.
As an indication of Vic’s respect for the competition, every detail was examined, “we’re using the brakes more and more as the bikes get faster”, so consequently the Ajay’s brakes came in for some attention.
This was mainly confined to getting the balance of the brakes set up properly – for example, Vic spent a lot of time experimenting with the rear brake leverage to get it just right.
The machine weighed in at 104kg, which was reasonably close to other works machines, that were then on the GP circuits, Vic drilled out and removed as much metal as possible.
He got the handling just how he wanted it and also had useful power right through the rev range.
Going by the results at Cadwell Park, he had proven that the machine would stand up to the tough life of international competitions, NV had just developed something more than a works prototype.
Added to that, like the earlier models of the Stormer this one also bought innovation to MX machinery, stylist Mick Ofield swept the seat up over the tank, allowing the rider to put his weight right over the front forks, compressing them to adjust the steering head angle, so providing sharper corning when needed.
So, why did this machine never progress into production?
Vic had developed a potent machine, with a left foot gear change, ripe for the US market, but its main competitor wasn’t to be on the motocross track, it was its big brother, who had been living right next door.
Sales of the Norton Commando had taken off and the issue was production capacity, Mike Jackson, then the AJS Sales Manager added, “It was more profitable than the Stormer and the market for the big four-stroke was growing, so it made sense to concentrate on that”, so production of the Stormer was ended.
So with a little irony, finally here is the reason for the demise of the AJS Stormer, the success of the Norton Commando.
The Stormer project itself was progressing and had produced another winner; in an extremly fast moving and competitive market, but at the same time it had also helped to develop the cause of its own downfall, the Norton Commando.
So where has this machine been hiding all these years?
I asked Nick Brown, “I know Terry quite well. We used to hang out together when we were kids. Our fathers were friends. His father, Gordon and his late brother Kelvin started a motorcycle shop in Ross on Wye, called Stormer Moto X sales”.
“I’ve been in touch recently with Terry and know of his Stormer collection. The ‘500’ is amazing, and it’s a real credit to him. I never knew one survived and I think he has most parts to build another one”.
So Terry Pickering has Stormers in the blood, and like a hound he sniffed this one out, with the help of Tony Pritchard, in a Yorkshire salvage yard, in pieces and in a very bad way. Most of those pieces though were there, but a friend for example had to make up some replica side panels, and he had to use a Honda 500 piston, which was the perfect match for size and bore.
He didn’t have the rubber connections for the exhaust bellows, no surprise, these parts would have long ago degraded, but found that the connector for a truck turbo was the perfect fit.
I’m used to this with my Stormer, a Jag part connects the airbox to the carburetor, I think it was often the case to look in a parts bin and repurpose rather than custom make.
But Terry didn’t stop there; he went on and found that miraculously, Villiers Services had a stash of spare barrels and heads, and also another prototype, a water-cooled version.
Then, as I know, a second frame became available on ebay, I had seen it in disbelief, and had thought about bidding on it for my spare ‘410’ engine, but Terry snatched it up.
So well done Terry, an amazing piece of AJS history has been found and preserved, beautifully, and maybe we will even see another, a water-cooled ‘AJS 500’, brilliant.
FB Red Devil / Frazer Inchley
I first saw the Red, Devil of our story, back in 1981, at Flint’s Farm; I thought it was amazing, Frazer, why did you choose to restore this machine over the other Stormer machines?
This is my grandfathers road racing helmet from 1965, we have a few items from his days at the AJS Race Competition workshops at Thruxton still knocking around the house, this one from his racing days on the Isle of Man, his favourite, and particularly means a great deal to me.
I, like my brother Robert, are both over six feet tall, my grandfather and grandmother, Joan, were quite small, so he suited road racing, where we took to the Motocross tracks.
Interestingly my grandfather’s house, in Knights Enham, was called ‘Wyfor’ which brings me to why I chose the FB Red Devil as the version of the Y4 that I particularly wished to own.
Firstly, it has the long travel front forks and extended rear suspension, it’s a good fit for my size, it’s a 360x which will give me a few more horses over the 250, and this is the final and ultimate variant of these excellent machines, so the perfect model for me to learn all about the bike my grandfather obviously loved.
I have been restoring it since last year, finding out all about its unique design, it will never be sold and already has huge sentimental value, I think it looks fantastic, will sound incredible and is the perfect bike for me.
Fluff Brown employed Mike Ridley to build the Red Devil frames, Mike now tells the story.
The Final Frame / Mick Ridley
Mick, why did Fluff start working on a new project, the Red Devil MkI?
The stocks of the Stormer frames, were running out, the last had been modified to enable the use of longer travel suspension, 12” at the front, and 10.5” at the back, so Fluff took this opportunity to explore a new Frame design. Fluff and Brian Curtis worked together designing the new frame, the basic design was to have the same geometry as the Stormer, but one of the aims was to reduce weight, so the heavy long tapered backbone would be replaced.
Another sacrifice would be the concentric wheel adjustment at the swinging arm pivot, which was also heavy, and caused the swingarm pivot to be further away from the gearbox sprocket.
This was a good design when the rear wheel travel was only 4.5”, but when longer travel suspension was used the large gap would cause chain tension problems.
FB Red Devil MkI / Terry Pickering / 2020
What other changes were made?
The footrests were to be moved further forward, to help riders shift their weight forward but the same petrol tank was to be used and this unfortunately led to unforeseen problems. Also the steering head was “waisted”, and 7/8” 16SWG Chromoly tubing was used.
It was an exciting time, Brian built the first prototype frame and the first 10/15 production ones quickly followed. The first bike handled well, and it did come out a great deal lighter than the modified Stormer frame.
So everything was proceeding well?
Yes, but after extensive testing by fast riders, we started to notice the first cracks, they appeared on the front down tubes, where the gusset ended. The gussets were made longer, but the cracks still appeared after time. Different ideas were used to stop the cracking, including Bronze welding the gussets, and using larger 1” diameter tubing, but the problem never went away. Fluff told me, if the frame is not right, you can just keep chasing the problem and it will never go away, so Fluff decided to re-design, take his time, we would bring it back inhouse and build our own frames.
FB Red Devil MkII / Frazer Inchley / 2020
So that’s when Fluff started working on a second version, the Red Devil MkII?
It was, and this time it was decided from the start, a new petrol tank was needed; the current Aluminium tank had been in use since 1978, it was a dated design. The more modern style tanks, that were now being used on MX bikes, were shorter and lower at the back, this allowed the rider to slide up on the tank in the corners, putting more weight over the front, compressing the long travel forks, increasing the steering head angle, which in turn produced better cornering.
We sourced a readily available plastic tank and Fluff decided to go with an old idea, a large diameter single down tube, finishing just above the central exhaust port.
A surface plate was bought to build the frame jig on, Fluff also invested in some tube bending equipment and bought a MIG welder. At that time MIG welding plants had only just become available, so I taught myself how to MIG weld, it was quite different to the Oxyacetylene welding and Bronze welding, that we had been doing up to now, but it was a great challenge and I enjoyed learning a new welding process.
We could have Bronze welded the frames, but that’s a slow, costly process, we needed to cure the problem of the twin down tubes cracking at the gusset ends and keep control over the unit price. I helped Fluff to build the frame jig, he taught me how to bend the tubing and build a frame. That became my job, I really enjoyed it, I was 18 and not only hand building frames, for one of the last, all British 2 Strokes, but also being taught how to design a new frame, by one of the best, a frame master.
How did the final frame project progress, the Red Devil MkII?
Firstly the top tube of the triangulated structure was shortened, and made at a steeper angle to allow for the shorter tank, and then the single down tube was basically put in the same position as the twin down tubes.
Secondly, the lower part of the triangulated section was butted straight onto the single tube, and when large gussets were added, this made the whole triangulated structure, much stronger.
This whole section was made as a sub-assembly, and was then put into the main frame jig; the rest of the frame was then built around it. The longer seat base, because of the shorter tank was also made as a sub-assembly, and then fitted to the main frame jig.
Did Fluff get it right?
On the first frame with the old alloy tank, the triangulated structure had to be quite long. It was thought that by fixing the front tubes, that came up from the swinging arm pivot point to a similar position, as they were on the old Stormer frame, that this would give maximum strength.
Unfortunatily by doing this, it created a weak point, where the seat base attached to the triangulated structure and it was this weak point that was the main cause of the cracking on the twin down tubes, it was a long time ago but we went on to produce 20 or so more MkII machines, including several variants with the Rotax engine.
Yes, Fluff was right, you had to start completely afresh, on the new frame these tubes attached to the same place as the seat base on the triangulated structure, and made that part of the frame much stronger, which in turn with the stronger top triangulated section, gave a much stronger frame, and completely cured the cracking problem.
The MkII single down tube frame was a good frame, it was lighter, and stronger than the MkI twin down tube frame, and together with the plastic tank, and new side panels was a good-looking modern, stylish, MX bike that handled very well.
Symphony for the Devil. Cliff Stevens. 2020