SILENCING THE MOTOR-CYCLE.

Evening Post, Volume XCIII, Issue 27, 31 January 1917, Page 11

SILENCING THE MOTOR-CYCLE.

j\losfc people are agreed that the average motor-cycle eugme is much noisier thau it should be. Apart from the question of the exhaust, in which respect the majority of engines are offenders in a larger or smaller degree, there is the noise created by the' valve mechanism, and this is specially noticeable in overhead valve eJigincs where the precaution, is not/ taken to encase the working parts outside the cylinder. It is one of tho penalties of tho retention of air cooling, the practice of which makes it obligatory to a large extent to leave the cylinders and other parts open to receive tho air currents and without any covering to keep the noise within bounds. In a few cases the designers have enclosed' the valve springs and tappets, and this has helped to a small measure to quieten the. engine, and if the plan is combined with adequate silencing arrangements lor Hie exhaust to get what, in the circumstances, amounts to I'easonable quietness. Breaking up of heavy power impulses and violent explosions, such as occur in a large single-cylinder engine, by the method of multiplying the number of cylinders and thus reducing the force exerted in. each individual unit, has tho effect of materially reducing the noise

created by the. engine, but unless there were other important advantages (o bo gained by this multiplying the'• number ol parts and adding to the cost of manufacture, we should not expect anyone to go to the trouble or risk of marketing a. four-cylinder machine. The time has assuredly arrived when there should be a, more concentrated effort on the part of motor-cycle designers to obtain more silent working in an all-round sense, not only where the engine alone is concerned, but in the transmission of the gears as well. To some it almost amounts to a punishment to drive a motor-cycle of the noisier kind, and thp.re is certainly a strong case to be made out against such machines. The problem having been solved to the partial satisfaction at least of some of the most-critical and expert motor-cyclists of the present time, it seems a pity that a larger number of manufacturers are not using'more earnest endeavours in the same direction. Many an otherwise highly successful design is spoiled, and undoubtedly lacks the popularity it might achieve because of the fact that whilst every attention - has been given to the other details, that of the noise created by the engine and,other parts whilst the machine is in motion has not been dealt with on equally thorough lines.