A  History of Classic Racing  50cc Motorcycles



This article is from Dave Brierly's scrap-book and was written in 1964. I have scanned it as the reproduction was poor and created this page which I trust you will find interesting. It gives an inside look on how a very consummate racer approached and loved the 50cc racing machine. I have added some images that were not in the published article.

THE development of 50cc pocket-size engines has been steadily increasing since their introduction and many famous manufacturers have been quick to realise the importance of this small engine unit; so much so that the FIM now includes a class for them in the World Championship series.

Up to the present, "the two stroke" appears to have the heals of the opposing four stroke and the speeds achieved on the various circuits have undoubtedly left many people scratching their heads in amazement.

The Suzuki Company, from Japan fought an out and out battle right up to the final round of the World Championship before Ernst Degner was able to claim the title from fellow countryman Anscheidt on a swift twelve speed West German Kreidler.

Both the Suzuki and the Kreidler are two-strokes, while the Honda is manufactured as an OHC four-stroke of both single and twin cylinder design, with a nine speed gearbox, the 1962 Suzuki having been equipped with eight speeds.

NO VALVES! It would appear that since the two-stroke engine does not have the increased weight introduced by the valve gear and the number of moving parts of the four-stroke, that even if the power out-puts of both machines were similar the power to weight ratio alone of the lighter two-stroke gives an immediate advantage

Another interesting feature of this small power unit is the fact that higher revs are permissible than those used by their larger counterparts. In fact these revs are now reaching unbelievable heights. The two-stroke machines developing maximum power at approximately 12,000 rpm and the four-stroke Hondas at 17,000 (in later development the RC116 reached 22000 revs.) . At such revs the engine behaves like a high speed turbine, being remarkably free from vibration, an annoyance commonplace on many large machines.

The actual technique of riding one of these “mighty atoms” differs slightly from that of a machine of larger capacity, in as much as the vast difference in weight, power and centre of gravity, has to be used to the best advantage.

Ulsterman Tommy Robb wraps himself well round the HONDA RC110 50cc racer in the 1963 TT at Governors Bridge. He finished third. This  is the smallest mount in the HONDA stable.

At lower speeds the rider can not use power to drive a 50 through a corner, or even expect power to help counteract any difficulty that may occur when leaning a machine into a bend. Often, on larger machines, that can be an advantage to have good drive when one requires more speed instantaneously, to help pull a motor bicycle away from a corner that tends to double back suddenly.

The importance of good streamlining plays a big part in the performance of a small bike such as a 50, and the more effectively a rider can tuck himself away, the more effective becomes the fairing and the power.

I think everyone must realise that where, on a larger capacity machine, the tendency to raise one’s head and shoulders above the screen is not such a tremendous hindrance, it is exactly the opposite on a racing 50.  Due to the already small frontal area and power output of the engine the increase in wind resistance by these parts of the human frame can increase the frontal area by about 30 percent. For this is me lifting my head going into a corner when riding a Guazzoni 50 at the Ulster GP.

So that if a rider does sit up for any reason and this frontal area is increased, the revs, and automatically the power, decreases rapidly. Then, when the rider flattens out once more, another period of time is required to attain the original maximum, so that from the moment of sitting up to when he can get behind the screen again a considerable time loss has taken place. This is an advantage to the opposing rider who has managed to keep behind the fairing for the duration of the same period.  Tommy Robb tucked low into the HONDA RC112 battles with Hugh Anderson mounted on a SUZUKI RM64 showing how low you have to bend to get behind the fairing.

I must stress that one’s discretion must be used as to when and where it is necessary to remain upright. For instance, if vision through the Perspex screen is not perfect for one reason or another, then it must be essential to look over the screen instead of through it.  Also, if one finds oneself going much too quickly round a corner, then it can be to his advantage to sit up slightly, allowing the machine a human air brake, rather than shut the throttle or touch the brakes. But if this is insufficient then by all means shut off and brake, and never feel cowardly about doing so.

In the actual braking for a tight corner it pays dividends to get one’s upper body as far out of the fairing as possible, so giving so much frontal area as can be made available. This assists the brakes which act very effectively on very light machines.  It must also be remembered that if the brakes are “A1” a rider can go much farther into a corner than on say a 125cc or 250cc due to the effort required to stop such a small weight being at a minimum.

NARROW TYRES! In view of the fact that these lightweights use such narrow section tyres, particular ease must be taken to avoid any unnecessarily bumpy sections of a circuit or places where the surface looks rather unsafe. With such a small surface area of tyre in contact with the road the point of break-away can come much quicker. Tyre width was between 2.50 and 2,75 inches for the rear tyre.

It would also appear that the technique of 'leaning in' further than the machine pays dividends for the same reason, to keep the lightweight as near vertical as possible with a maximum of tyre tread on the road surface.

Apart from the points mentioned above, I think that racing a “50” is similar to any other machine. When one has the spirit to compete against fellow competitors the size of the machine makes very little difference.

But a few final words of advice; If you are about to enter for your first 50cc race, have somebody handy at the finish with a bottle of embrocation to massage your neck muscles

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