From the December 1933 Issue of Motorcyclist Magazine.
The Motor Cycle Show is back at Olympia. Last year, what with the industrial depression and all, the manufacturers decided to let this annual fixture stand over for the first time since Great War days, but on November 25th the exhibition opened once again. Again, too, it has had the “Best Yet” verdict from every practical judge.
The British Show is the most important of its kind in the world. It would be curious if it were not. Conditions in Britain have favored motorcycle development and just after the war British manufacturers got ahead far more quickly with the job of turning out better motors than did their rivals in other European countries. Olympia became, as a natural consequence, the chief international market place. That position it still holds and to this year’s Show buyers have come from all over the globe.
Good motorcycles are being made I many other countries. We in Britain recognize that. Competition is keen. Great progress has been made in Germany and in Italy, and to a lesser extent in France. But Olympia keeps its lead-even if a German machine does hold the speed record and Italian riders did win the International Six Days’ Trophy.
On the business side then, Olympia is an occasion of standing. It counts in our national commerce.
It is also an event in London life. Olympia itself, the building, is the finest exhibition hall that we have-and considered as a spectacle alone the Show beats the Paris Salon and the other continental fixtures, and does so pretty easily. The Minister of Transport himself was to open the Show, and among the visitors was expected to be H.R.H. the Duke of Gloucester. Prince Henry, as he is still sometimes called, is the third son of H.M. The King, and, like his brothers, has run a motorcycle of his own.
Our Show, then, is a big affair all round. I have tried in the foregoing, to indicate how big. It is the magnitude of it all that strikes the average American first, or so they have told me.
Motorcycling in Britain is going strong, despite the depression. The annual traffic census just completed by our Automobile Association shows a 12% increase in riding, and enthusiasm for racing and the sporting side generally has never been greater. Any curtailment there has been caused simply by the prevailing financial conditions. Even in spite of these, the number of motorcycle clubs affiliated to the Auto-Cycle Union, our national governing body, has reached a record figure during the depression period.
There are about thirty different makes of motorcycles on view at Olympia, and in addition of course there are a few makers in a small way of business who are not exhibiting. The variety of models must prove astonishing to the visitor from the States. Most of the leading makers offer an extensive range; the Triumph company, for instance, markets no fewer than eighteen different types.
This is due to three main causes. One is that the British taxation system is based on a scale of engine capacities, which naturally tends to multiply types. Another is that the sports model is tending more and more to become a specialized product, different from the general-purpose or “utility” model. Chiefly however, the reason is that the European motorcyclist is fastidious-faddy if you like -and demands a mount that is absolutely exactly to his taste. Something merely like it will not do; it has to be correct to the nearest millimeter.
The types offered by the British makers are classified by capacity, cubic centimeters being quoted instead of cubic inches. They begin with the 150 c.c. model, which has a cubic-inch capacity of 9.15. These little machines have gained enormous popularity of recent years. Two-stroke engines were almost exclusively favored for them until two or three years ago, but there are now several machines in this class with overhead valve four-strokes. Reckoning the dollar as being worth 4s. British money, or $5 to the £, prices for this type at Olympia run between $100 and $150.
The new 150 c.c. B.S.A., introduced to the British public at Olympia. It has an o.h.v. mot
These “150s” as we call them give very good service for general purpose solo riding. They will do anything up to about 50 m.p.h. without any difficulty, and of course running costs are very low. As we pay about 36 cents a gallon for petrol (which you call “gasoline”) and around $2 a gallon for oil, operational figures are definitely a consideration with us. Our machines are taxed, too, at anything between nearly $4 and $15 annually, whilst insurance against accidents to third parties is compulsory by law, this costing anything from $5 a year. The 250 c.c. (15.05 cu. in) class is greatly favored for solo riding, and many such machines are now used with sidecars. $200 is an average price for such a mount. Both two-stroke and four-stroke engines may be had.
The 350 c.c. (21.35 cu. in.) size is rather less popular than it was, owing to a change in the taxation scale, and the 500 c.c. (30.50 cu. in.) is the most general type for solo riders who want something bigger than a 250, and for service with a sidecar. The 500 is also the sportsman’s favorite. It is of course the size used in the Senior T.T. and an o.h.v. single cylinder engine is the normal equipment. Such a model costs about $250.
There are a few of what we call “big singles,” of around 600 c.c., and some multi-cylinder mounts of similar size, while the 1,000 jobs are not many. The Britisher, as a rule, favors a fairly light mount, and is therefore inclined to turn down the large machine on the score of weight.
The present Show indicates, in fact, that the very small motor is making the most progress. The typical solo motorcycle of twenty years ago was a 500; by 1923 the 350 was quite as popular, and at the present time the 250 has a good enough performance for the average man, with the 150 as a perfectly possible substitute. Running costs, particularly taxation, are at the bottom of this, the national dislike of weight is a factor. And there is the very reasonable argument that, if the small motor will do the job, why bother with anything else?
The big machine, at any rate for solo work, is really being kept alive mainly by the interest of sporting riders.
Although the two-stroke engine is no longer supreme in the 150 class, as it was until recently, it is by no means a back number. On the contrary, one or two prominent makers who dropped it a few years ago have gone back to the type, while two-stroke engines are now being turned out from, probably, a greater number of factories than ever before. Very considerable improvements have been made, too, in efficiency of late. An important development is the adoption of water-cooling for small, two-strokes.
This improves the stamina of the engine very considerably, and the trend is likely to continue. The Scott remains the only water-cooled twin on the British market, though it is interesting that such engines are being developed in Germany. Incidentally, we have in this country the British Two-Stroke Club, which is active in promoting the interests of riders of such machines.
For general service purposes, there is a tendency to make leg-shields standard equipment and also to encase, as far as possible, the engine and its fittings. Strong efforts are being made, that is, to make motorcycling a cleaner business all round. It is not too easy to enclose the engine and at the same time leave it reasonably accessible for maintenance operations, but the job has been effectively done by several designers.
To go to the opposite end of the scale, the modern sports model is a highly specialized type, and the rider may now obtain a genuine racing job without any difficulty. Equipments, too, can be varied very considerably, and the owner can obtain a mount for use in either trials or racing, according to his hobby. What you would call in the States the “custom-built” model is becoming a vogue. One or two makers specialize in it.
The 150 c.c. New Imperial, which has an o.h.v. motor built up with a three-speed gearbox.
In the details of engine design there are no changes of outstanding importance, or any indications of marked general trends. Both overhead camshafts and push rods are still popular, for example, for overhead valve operation, and single and double-port heads are fairly evenly divided.
What is of far greater importance, however, is the trend towards the multi-cylinder engine. This seems quite definite. The multi-cylinder is desirable from two particularly important points of view. It gives easier starting, which is a matter of great concern to our older and less athletic riders, while it also reduces noise-and the noise nuisance has become serious in Britain, where the public is perhaps specially sensitive to it. Many leading authorities contend, in fact, that the future of the motorcycle may quite well depend to some extent on the dropping of the single cylinder engine except in its smallest sizes. That is an extreme view, but the fact that it is held has significance.
We have on the British market two four-cylinder machines of home manufacture, and it is rather remarkable that neither is of the in-line type. The straight four is the conventional pattern and it seems singular that it should not be produced in this country at the present time. Our Ariel four consists of what is practically a couple of vertical twin units set side by side. There are two crankshafts, geared together, an arrangement that is incidentally common with large aircraft motors, and the overhead camshaft is chain-driven. This type of engine is generally known as the “square” four. The other, made by the Matchless concern, is a V-four, consisting in effect of two V-twin engines set side by side. The whole job is highly ingenious, the cylinders, which are set at a narrow angle, being cast together in a single block. An overhead camshaft, bevel-driven, is fitted. Both these models have gained a following since their introduction for the 1931 season.
The Triumph vertical twin, of 650 c.c. one of the outstanding innovations of the Olympia s
While there are no new fours, the present Show contains two medium-size twins of importance. The makers are the B.S.A. and Triumph concerns, which are among the leaders of the industry, and it therefore seems certain that their lead is likely to be generally followed. The 500 c.c. B.S.A. twin, which was originally developed by the makers for Army service, is of the V pattern, with overhead valves operated by neatly enclosed push rods. It is a perfectly straightforward layout and the machine is rumored as having a remarkable performance. The Triumph twin is of distinctly peculiar design, the cylinders being vertical, with the push rods for the o.h.v. gear set at a considerable angle. The crankshaft is arranged for a firing angle of 360 degrees, which means that the pistons move together. The gearbox is built up with the crankcase, the primary drive being by gearwheels of the double helical type. The capacity of the engine is 650 c.c. (39.76 cu. in.) and the machine is no doubt intended mainly for use with a sidecar.
Dry sump lubrication is general on British engines. For two-strokes, the “petroil” system, in which the lubricant is mixed with the fuel and enters the engine by way of the carburetor, is still common. Magneto ignition is most favored; the coil system has not made much headway. Bowden wire (stranded cable) mechanism is standard for handlebar controls; the bars themselves are “cleaner” and twist grips are now usual. A great deal of improvement has been made in silencing. Clutches are of the multi-plate type and primary transmissions, for which a single roller chain is the rule, are fully enclosed. Four-speed gearboxes are general on all but the smallest and cheapest machines, and foot-operated gear-changes are employed for sport models. Brakes are of generous proportions, 8-inch drums being normal for larger machines, and a number of makers have standardized quickly-detachable wheels. Most machines now have hinged rear guards, to improve the accessibility of the wheel. Larger tanks are common for 1934.
Frame design at present shows wide diversity. Many firms show no sign of abandoning tubes, but on the other hand the use of forgings and pressings is extending, while a few concerns make their frames entirely in pressed steel. Fork assemblies are very much more massive than was the case a few years ago.
Lastly among general tendencies, there is a very great advance in the matter of sidecar design. Two or three years ago it could have been said with some truth that British makers were hardly turning out such attractive sidecars as some of their Continental rivals, but that criticism cannot now be made. In roominess, general comfort and appearance, sidecar bodies have advanced enormously, while there has also been some development of chassis details.