Best of British: Cheney / Triumph Tiger Cub built to battle the two-strokes…
If you dig very far into the history of motocross and scrambles, you’re sure to come across the name Eric Cheney, an off-road racer and genius builder whose machines became legendary in their own time.
“In the hands of the best riders, Eric’s original machines and the modern reproductions, which his son Simon hand-builds today, still win many races and championships, not only here in the UK but all over the world.” —Classic Dirt Bike Rider
Cheney is particularly known for his purpose-built racing frames, developed in an era when engine performance was quickly outpacing that of chassis and suspension development. To fill the gap, boutique shops began to turn out their own chassis designs in the 1960s, tailored to fit various British or Japanese power plants.
Many of those frame builders, such as Eric Cheney and the Rickman brothers, were based in the UK, where off-road racing was so popular. Working out of small shops, they managed to create frames that performed light-years ahead of the stock factory designs.
In the early ’70s, Cheney began working on a twin-shock cantilever frame, constructed of high-quality Reynolds 531 tubing and bronze-welded by Eric himself. As the story goes, Cheney was unhappy with the performance of the original prototypes and sold them.
A year later, he received some newly designed gas and oil shocks from Girling, which completely transformed and perfected the frame’s performance, and he went on to produce cantilever frames built to house Honda XL250/350 engines with much success.
That’s where the unique “Cantilever Cub” you see here comes into the story. The bike is owned and raced by our new friend Graham Watson, whose late father, David, wanted to build his twelve-year-old son a four-stroke British race bike that could battle and win against the foreign machinery quickly rising to motocross supremacy in the 1970s:
“In the back of my dad’s mind he was still convinced he could build a British bike to compete with the growing input of Japanese and European bikes.” –Graham Watson
Through an ad in the back of a motorcycle magazine, the elder Watson spotted a frame for sale that might just be the ticket. On a whim, he grabbed his son and they headed 300+ miles to the south of England, where they purchased something quite special — one of those original Cheney cantilever prototypes:
“The frame was confirmed as one of the first three prototypes that Eric and his team designed and fabricated back in 1973.”
The Watsons matched that 1973 Cheney cantilever frame with a 1964 Triumph Tiger Cub engine, and the rest is history — a father-and-son saga of racing, wrenching, and the two-wheeled ties that make our sport so special.
Cantilever Cub: In the Owner’s Words
The full history of my Cheney cantilever prototype Triumph Tiger Cub — by Graham Watson.
Part 1: The vision and the frame
My father had always built his own bikes when he sand-raced and grass-tracked back in the ’40s, ’50s, and ’60s, as did most riders of that era.
So when I showed an interest in motorbikes, my father converted a triumph Tina scooter, cutting the frame to lower it, removing the petrol tank from under the seat and mounting it in front so it looked like a motorbike, and it was small enough to fit a five year old.
I progressed to larger bikes, and as soon as I was old enough joined my local motorcycle scramble club (as it was called in those days), riding a converted Suzuki k10p 80cc, then a Suzuki TS90 and so on and so on to the first RM’s, etc. But in the back of my dad’s mind he was still convinced he could build a British bike to compete with the growing input of Japanese and European bikes.
So back in the early ’70s, my father noticed an ad in the motorcycle news advertising a frame for sale down in Hants, UK. After Dad had spoken to the guy selling it on the phone, and on a complete whim, we set off down to see it (we lived in the north of England — Windermere to Hants was quite a journey).
This is what I remember being told when my father bought the frame. I was 12 at the time! The man down in Hants had bought two or all three (not sure, as it’s a long time ago now) of the prototype frames from Cheney to do basically what my father wanted to do.
The frame was confirmed as one of the first three prototypes that Eric and his team designed and fabricated back in 1973. This is the same time Cheney was determined to build a world-class bike to compete in the world GP’s, so there was quite a bit of design work going on from 1971 to 1974, which is well documented.
The cantilever frame was “near perfect,” giving good ride height, ground clearance, and excellent suspension travel. The first test wasn’t up to Eric’s high standards — it didn’t handle that well, the rear wheel spent more time off the ground than on it. So back to the drawing board, some improvements were carried out but still not good enough. At this point the frames were put to one side and more important work took over. This could have been the end, never to see the light of day.
About 12 months later, Girling of Birmingham gave Cheney some newly designed rear shocks — “they had gas in them as well as oil.” One of Eric’s engineers suggested it might improve that little cantilever frame we made a bit ago. What a transformation, perfect! I believe 20 new modified larger frames were built to house the new Honda XL 250/350 engines. Most of my information on the Honda XL version has come from France, where most of them were sold — I think to one company — back in 1974.
My father bought one of the original prototype frames, took it home, and at this point we had a frame and a pair of front forks and Dad’s vision. The rest as they say is history.
Hopefully this has confirmed to all the cynics that my little Cheney Cub is pre-1974 eligible.
Part 2: The build and the many years riding her
The interesting bit for all the bike builders.
Recap: We had a frame, a pair of front forks, and my dad’s vision — that was it!
First to find a British engine — there were only really two four-stroke options: BSA C15, but these would need to be sleeved down, or a Triumph Tiger Cub. We found a Tiger Cub engine in a breakers yard in Preston!
Now we needed wheels, petrol tank, etc. So a trip up to Egremont, Cumbria to Bill Brown’s, where he kindly showed us a room full of all sorts. We found a petrol tank, front and rear wheels, mud guards etc.
The engine was stripped to find not a lot we could re-use (remember this is before the internet). So magazines were bought and letters sent out, and over the next 6-9 months we managed to find a new 9:1 piston, oil pump, barrel and cylinder head, phosphor bronze bearings, carburettor, electronic ignition. Basically everything had to be replaced.
Once the engine was re-built, it was time to fit it into the frame. Engine mounts were fabricated and the engine fitted. Then aligning the rear wheel so both front and rear sprockets were in alignment. The front wheel hub was identified as a CZ, so new brakes were bought and fitted. Dad machined both wheel spindle, chain guard, engine mountings, etc. Then wew 12” rear shocks, new rear sprocket, and we were nearly there. (Note 12″ shocks mainly due to me being a short arse back then.)
That just left the fine tuning. Hours up Garburn green lanes (when you could still go up on a bike) until my father was happy. My first race was at the Cumbria youth club on the Broughton Hill side track. Due to my previous experience, I was in the 125cc expert class (Fulton, Mcneice, Lewis, etc.).
The bike got a lot of interest because of its looks, but no one thought it would be any good against the now dominating Suzuki, Honda, Kawasaki, and Yamaha machines.
First race: First into the first corner. By the third lap, I was still fourth, but going down one of the hills flat-out, I dropped it down two gears (riding it like a two-stroke) and dropped the exhaust valve straight through the piston — back to the drawing board.
The new valve springs supplied were meant to be sport springs — they weren’t. Had to have a re-bore, new piston and new, confirmed sport valves and springs. Also, Dad had to fabricate a new oil tank, as we could not be sure if any metal had gone into the frame! Had to remove the airbox from under the seat to accommodate the new oil tank. Oh, and I stopped riding my two-stroke!
All done and out again. This time took four teeth out of second gear! Basically we had a couple of issues — too much strain on the gearbox, valves bouncing, and engine getting too hot.
Gearbox issue sorted — Dad built a cush-drive Greeves hub into the rear wheel and re-spoked it slightly off centre to get the chain 100% inline. Extra strong valves and springs were fitted and a homemade barrel with larger fins was fabricated.
I then raced it for 1.5 seasons in the 125cc expert ACU class, finishing mid-field, annoying a few dads who’d bought their sons brand-new Japanese machines. After finishing in the schoolboys class, I did a couple of grass tracks and senior 250 meeting. Then drink and girls came along, then wife and kids, so the bike was covered up in the garage.
In 1994, my father and I were invited to what was then the Westmoreland Motorcycle Club’s nostalgia meeting to go round in the interval with other older riders from the ’40s, ’50s, ’60s, and ’70s. This is when it all started again. The following year I entered the meeting in the pre-74 up to 250 class and enjoyed every minute — “pure nostalgia.”
Over the last 27 years, we fitted a new gearbox, new rings, converted it to methanol, broken down a couple of times, spent far too much money on it, and probably used about 30 liters of polish. Thanks, Dad.
So in summary, the engine is from 1964 (the same age as its rider). At this point, “no fancy magical modern parts inside.” It was a standard 199cc with a 9:1 piston, close-ratio gearbox, 17-tooth front sprocket has and 57-tooth rear. The rear hub is a Greaves cush drive; it has sport valves and springs, Betor forks, an electronic ignition (STK-202 Electrex), a 13mm carb (Amal 626 L301), and I run it on methanol. The frame is one of three prototype Cheney cantilever frames designed and manufactured in 1973.
It’s not quite quick enough to win a pre-74 up to 250cc class, but I don’t disgrace myself or my dad. For me it’s pure nostalgia, and as it’s unique, it always gets lots of attention, especially when it lasts a whole meeting.
We sadly lost my father early in 2020 from dementia. Unfortunately, I didn’t watch him enough when he was building it or keeping it going. So when it needs major TLC, my good friend and excellent bike builder Chris from the Triumph Tiger Cub workshop helps me put it back together.
In 2017, Chris completely rebuilt the engine. (By this time dad’s dementia had taken over.) It now has a 10:1 piston, new oil pump, new clutch, up-to-date ignition system, 55t rear sprocket, and some of Chris’s special machined parts. It’s still 199cc, and everything else is original from when Dad built it.
I try and get over to the UK and compete in a couple of meetings each year and have done since 1994. Usually the Mosley/Hanbury or the Kendal meetings, depending on the dates. We had a few teething problems since the rebuild engine.
Rear engine mounting broke in 2017.
I came over in 2018 to do the Mosley’s, but unfortunately it was cancelled due to the weather. In 2019, we came over and I rode at the fantastic new track at Clun, the Mosley’s classic scramble meeting, but had a carburettor issue, though I managed to finish the meeting in one piece. (Note to self: I need to spend a bit more time on her and ride her a bit more.)
Although not yet fully tested, all known problems sorted — even fitted a silencer/end pipe to please the scrutineers. Last year, 2020, I was entered the two Acorns meetings, as the dates in June and August were perfect for me. Unfortunately with everything going on in the world in 2020 both were cancelled. Fingers crossed for later this year.