Small but perfectly formed
Three decades ago, bike racing’s teeniest motorcycle World Championship was consigned to the dustbin of history. The 50cc series survived for 22 seasons, during which time it remained resolutely unglamorous while providing some of the most fascinating engines ever seen on a Grand Prix grid.
The series enjoyed its heyday in the latter half of the 1960s, when Suzuki and Honda fought a frenzied two-stroke versus four-stroke duel for supremacy. By the time the FIM called time on this arms race in a toy box, the fastest 50s were generating 360 horsepower per litre, revving to 22,000rpm and using 14-speed gearboxes.
Suzuki’s 32.5mm x 30mm twin was the most successful bike of the era and was about to be replaced by a 28 x 26.5mm triple when the FIM decided to end the madness by restricting the class to single-cylinder engines. The Suzuki’s final derivation, the RK67, had 18 horsepower at 17,300rpm through a 14-speed gearbox. Honda’s twin RC116 made 14bhp at 21,500rpm through a nine-speed gearbox.
The bikes weighed about 50 kilos and ran two-inch tyres. Some used bicycle brakes.
The engines were wonderful things, with pistons like espresso cups and gearboxes like watches. Just as remarkable were the techniques used by riders to eke the best out of these machines.
“You never had more than 500 revs to play with, so you were constantly monitoring the revs, using the clutch, trying to find another hundred rpm – it was minimal stuff,” says New Zealander Hugh Anderson, who won the 1965 and 1966 50cc world titles on Suzuki’s twin.
“A little made a big difference. I enjoyed riding them because you were mentally active in a different way – you had to work very kindly and very sensitively with the engine to allow it to do its best.”
Riding a 50 was not unlike riding a bicycle: maintaining momentum was everything, never losing a single rev through the corners or on the straights.
“The most important thing was carrying speed, because losing any revs would lose you a lot of time,” recalls Stuart Graham who won the 1967 50cc TT for Suzuki. “The twin had power between 17,000 and 17,500rpm, so you were literally playing a tune on the gearbox and keeping tucked in behind the screen to the bitter end.”
Anderson was particularly good at contorting himself into an aerodynamic shape on these Lilliputian devices. “I was very flexible. A party piece of mine was getting one foot behind my head. I could get the second one there too, but then I couldn’t breathe…”
Screwing yourself into a ball was also tricky on the track. “I had bloody great water blisters on my elbows because they were tucked in against the cylinder heads and my calves got burned on the expansion chamber shields,” recalls Anderson, who made detailed circuit notes to help him get the maximum out of the angry little engines. “I wrote it all down: change down 12 gears for this corner, 10 for that corner and so on. You had to make the effort to get the best from the engine.”
Some 50cc racers wore boots a size too small – to marginally improve aerodynamics – and most did whatever they could to keep their weight down. They were all jockey-sized anyway – they wouldn’t even fit on the bikes otherwise – but every ounce counts when you’ve got less than 20 horsepower beneath you. East German Ernst Degner, who won the inaugural 1962 50cc World Championship, kept himself on a permanent diet, took regular saunas and forbade friends from eating chocolate in his presence.
Anderson took his dedication to a whole new level of Zen. “It was important to have consistency and I needed a routine, so I didn’t eat in restaurants and didn’t sleep in hotels,” he says. “I slept in my caravan and ate my wife Janny’s food. I kept away from restaurants – all the talk, too much happening – and in hotels every bed is different. I’d park my van next to the pits so I could be with my bikes.”
Many 50cc riders had engineering backgrounds, because the better you understood the intricacies of the engines, the faster you were likely to go. Although Anderson rode for the Suzuki factory, and therefore had Japanese mechanics working on his machines, he took a close personal interest in his engines, filing down the high spots on pistons to help prevent seizures, the dreaded downside of the super-quick two-stroke.
Honda only won the title once – to Suzuki’s half-dozen successes – because at that time the company wasn’t prepared to resort to two-stroke sorcery to achieve the all-important maximum peak power.
“Once Suzuki brought out its twin, we were hammered, we couldn’t even slipstream the bugger,” says Ralph Bryans, who won Honda’s only 50cc title in 1966. “We were lucky because we had a wider power band than they did, but we still had to keep the thing absolutely on song the whole time – anything between 19,000 and 21,000rpm. If you were out of the powerband you weren’t going anywhere. To get the thing off the line you used the clutch a lot – you got it up to 18,000, you feathered the clutch to find the grip and off you went.”
Honda engineers tried everything and anything to close the gap on the two-strokes, including bicycle-style caliper brakes.“The big advantage was much less unsprung weight,” adds Bryans, who won the title on Honda’s bicycle-braked RC166. “It worked so well that Honda tried it on the 125 four, but the rim got so hot that it melted the tyre bead.”
After their 1966 success, Honda knew the game was up and withdrew from the class. Then when the FIM restricted the category to singles, Suzuki also withdrew. The Japanese factories were replaced by smaller European concerns whose race shops were run by garagiste engineers who never received the respect they deserved, because the world’s attention was always focused on the bigger, more glamorous classes.