THE MOTOR

Evening Post, Volume XCVIII, Issue 38, 14 August 1919, Page 11

THE MOTOR

NEW MOTOR-CYCLE DESIGNS

EXPECTED DEVELOPMENTS.

(By "Chassis.")

A' great deal of thought is being expended at the present time on motorcycle design and possible further developments in'connection therewith. The majority of British firms are content for the time being to perpetuate their 1914 or 1915 models, with perhaps a few improvements here and there, whilst continuing their experiments and preparatory work for the introduction of new designs, next season. The demand for motor-cycles at the present time is sucli that that purchasers are not too particular so long as they are able to obtain machines of a generally up-to-date character, and which represent' the latest practice in their own particular field. A few English firms have introduced entirely new models for this year, and probably will perpetuate these types in 1920 with such modifications as may then appear necessary. There is reason to suppose that one or two of these firms will market four-cylinder designs. It is not anticipated, however, that any revolutionary methods in general design will result, but it is thought that there will be a wider tendency to adopt twin-cylin-der in preference to single-cylinder engines. A type that would appeal very strongly to many, if manufactured on a wider scale, is the twin-cylinder two-stroke. As regards transmission, it seems almost certain that the chain will continue to play an all-important part, but with the introduction of four-oyUnder models there will be an extension of the shaft and bevel-gear drive, with, a« alternative, a worm drive, or- even one in which friction discs are used, MOTOR LORRY TRANSPORT. Nothing could have demonstrated'the f possibilities of the motor lorry for trans. \ port more than the work performed by these vehicles in France during the war j period.. When it is considered that a large proportion of the chassis were designed for use on good roads, the manner in which they stood up to work under active service conditions is remarkable. I Under no other conditions could such experience have been gained, Vehicles were worked usually under the worst pc# sible conditions—bad roads, heavy loads, many inexperienced drivers, and lack pf. time for attention and repair facilities., Under such circumstances'it is natural that defects showed, and a. certain nu.m= ber of failures occurred, At the same, s :ime, much valuable information, was, ob, tainabla from such defects as developed? ' Though under normal conditions many pf these failures would not have occurred, it will no doubt be the aim of the designers to obviate the possibility of similar troubles in the future, During the TO?» motor transport from a commercial point of view has not progressed in Australasia, In fact it has had a considerable setback, but with the advent of the post- | war vehicles the motor lorry should soon take its right place as a moat efficient and economical means of transport in Aus'iralian commercial centres, TIPS FOR MOTORISTS, [ In vulcanising inner tubes a bit of f the fabric known as Holland cloth! I miake3 a good substitute for the commonly used newspaper, It is difficult to get the paper off after the job is done, while the cloth pulls off very easily. The cloth should oe trimimed, so that it just covers the vulcanising plate, and will-not catch fire and burn the rubber. It serves quite as well as the paper to prevent the plate sticking, and has the advantage of coming away easily .vfterwards. If a set of inside and outside micrometers is no tavailable, and the repairman is in doubt as to whether the new piston is too tight a fit in the cylinder, the next nearest accurate operation is this : Place the piston in a rather slowheating fire, and let it come .to heat of about 600 degrees Fahrenheit. While it is in this condition place it in the cylinder, and work it up and down. If the piston works freely, it is evident there will be little danger of its sticking in the cylinder from heat expansion. While this cannot be regarded as accurate; it will serve. One of the most useful things to carry in the car on tours is twenty.five feet of half-inch manila rope, which has almost endless uses, In the first place it is an admirable tow rope. It can be draped around axle and spring after some of the spring leaves have been broken, to get home without breaking, the rest of the leaves. It can be cut in two and. wrapped around the rear tires to give traction in some mud hole 3 where it would be impossible to fasten the i chains. The rope can even bo*l used as ■a. tire when the last 'spa-re has blown out, and will save the rim on the jourley home. i When a motor-car is running' fifteen miles an hour, and is brought to an abrupt stop, the impact is equal to that of a body striking the earth from a height of thirteen feet. When a car is running fifty miles an hour, and is atop;ed in its tracks, the impact is equal to 7 ■ that of a 120-foot fall. Draw your own '. conclusions. I It is possible to .get increase am- , perage from partly run-down dry cells by crowding down the material near the carbon element with a small piece of wood and a hammer. This lessens the obstructing material from around the carbon and permits free chemical action. The asphaltum on top of the cell may be sealed again, by application of a little taat. Valve springs that are too stiff may close the valves with so much force that the heads may be broken from the stems or they may break the stems at the key ■ slots. On the other hand, valve springs • that are too weak to hold the valves on the cams will make the engine weak at high speeds and produce chattering owing to belated seating of the valves. In this connection it must be remembered that too-stiff valve stems, even if they do not injure the valves seats by constant hammering, are consuming power that could be better used eleswhere. The motorist is sometimes puzzled to know just what shape his bearings are in and does not know how to test them. Connecting rod bearings should be tested by tapping them very gently with a hammer and watching for play. For the crank-shaft bearings, try rocking the shaft a little by hand with the petcocks open; if you can do this the bearings a-re all right.