Cycling and Motor Notes

Otago Witness, Issue 3215, 27 October 1915, Page 58

Cycling and Motor Notes

BY DEMON.

bility trial to Timaru and back during tht week-end. Thirteen competitors loft Dunedin on Saturday. The first man left at 10.30 and tho remainder at one-minute in torvals. Checks were bold at Palmerston, (fcimaru, and Timaru. The club captain (Mr A. E. M'Dougail) preceded the men, and arranged secret checks between the above-mentioned places. Some two or three riders failed to reach their destination on Saturday to time. The following arrived at the railway station on Monday bet ween 5 and 6 o’clock F. M'Donald, S. It. Mcddor, H. Markham, H. Paul, J. Decide, E. Strain, 11. Burrow, J. Dunne, T. W. King, and F. Drake. As tho checking cards from Timaru and Oamaru arc not yet to hand, tho winner will not bo known for a day or two. There is one adjustment of a fourcylinder engine, which, if properly carried out. ma kes an enormous difference to the running of the vehicle, and yet it is one which is to a largo extent neglected by motorists —namely, the adjustment of tho tappets that raise and lower the vales. In all modern cars the height of those tappets is adjustable, and their height will determine the height to which the valve is lifted from its seat. This adjustment will not, of course, alter the maximum lift and fall, which arc determined by the contour of the cam ; but where the tappet does not reach to the valve when the latter is on its seat, and tho tappet is at the bottom of its travel, the space interval will represent a certain loes cd areas of opening, and in that respect the gases—ingoing or outgoing. as the case may be—will bo throttled. weather certain conditions arc brought about in an automobile which calls for alteration in treatment if the best service is to be secured. Thicker oil can be used with advantage when tho temperature is such that there is no danger of it failing to reach the bearings. This i& especially desirable if the cylinders and pistons are inclined to leak gas. It is a bad plan to run tho engine idle in hot weather, as it overheats more quickly than under ordinary conditions. In coasting, the engine can bo cooled a great deal by cutting off the ignition and opening the throttle, thus allowing the cool vapour to enter the cylinders. Tho better plan, however, is to have an extra air inlet on tho induction pipe, which can bo opened to enable the cool air to rush through the cylinder's without wasting petrol or causing explosions in tho _ silencer when the spark is switched 1 on again. The high gear should be used as much as possible, and when country touring tho cutout may be opened to allow the hot exhaust gases a quicker passage to the open air. In hot weather more air can be mixed with the petrol. This will save fuel and

lessen the chances of the engine overheat ing. “How to Keep Down Tyre Expense is the title of an interesting booklet issued by the United States Tyre Company. A number of hints are given concerning the j treatment and care of tyres, and helpful tables show the air pressure and the weight which each tyre should carry. The use of a pressure gauge is strongly recommended, and the suggested pressure for the various tyre sizes is as follows: —Four-inch, 801 b; 4iin, 901 b, sin, 1001 b; siin, 1101 b. The booklet emphasises the fact that no motorist can hope to obtain the best results from hjs tyres unless he drives his car with a certain degree of caution and avoids the numerous abuses which aid in shortening the life of the tyres. A fierce and unnecessary strain is imposed by rounding corners at high speed, while running in ruts, tram rails, or against kerbs chafes the rubber, and in time exposes the fabric. Quick starting and stopping should also be avoided. Extra- covers carried on the car should be covered to protect them from the sunlight, which has an injurious effect on rubber. Spare tubes should not be stored where they will come into contact with tools or oil. It is a good plan to tie a piece of cloth around the valve stem before placing a tube in the tube-bag. This will present the stem from injuring tho rubber. Heat, light, and oil arc natural enemies of rubber, and when grease comes in contact with tyres it should be immediately removed with benzine or petrol. EXPLOSIONS IN THE EXHAUST BOX. When explosions are continually occurring in the exhaust-box of a car, tho vehicle becomes a trial to its owner, and a nuisance to the general public. Tho main cause of the trouble is that unfired charges from tho engine collect in the exhaust-box, and if a slow-burning charge in one of the cylinders follows the ejection of those charges, it is hound to explode them. In this, as in the case of back-firing along the Induction pipe, the gas is tho principal factor contributing to the trouble. If. when on tho road, a car suddenly develops the defect of persistent, “banging” in the exhaust-box and loss of power (which will follow as a matter of course), it will be safe to assume that there is something wrong with the carburetter or the petrol supply. A block in the jet or petrol pipe, or the tank running short of spirit, are almost invariab'v indicated by explosions in the silencer. These explosions may vary in intensity a great deal: that depends largely on the typo of silencer fitted. The more resistance that is offered to tho exploded charges the louder the report will be, and in somo cases the ends of the box may be blown out. A good idea, which, however, is rarely put into practice, is to fit a safety valve in the silencer which will open under any unduo internal pressure. If this wore done, many a silencer would have been saved from destruction, Another reason why these explosions

occur is switching on and off with the throttle open—a practice some motor; sts adopt when descending hills through having no provision for throwing an air-port open so that the cylinders can draw in air instead ’ of mixture for compression to obtain an engine-braking effect. When switching on again, there is always the risk that the exhaust-box, full of unexplodcd mixture, will go off, especially when the spark is retarded, for then tho charge will still bo in process of combustion when it is ejected through the exhaust valve. A badly-fitting exhaust valve, which allows the mixture to leak past on the compression stroke, sometimes has the same effect. AUSTRALIAN-MADE TYRES. To-day tho average Australian motorist is fully aware of tho real importance of supporting home industries. In tho past a considerable number of foreign-made tyres have found a market m this country, resulting in large sums of money going overseas. In” the 12 months previous to the war over £350,000 of manufactured Rubber goods, mostly motor tyres, were imported into tho Commonwealth. There was really no sound reason why those imports should ha ye been so high, for tho Australian-made article has no superior in tho world, either for quality or service. In this direction Australia is well able to bo self-supporting, thereby keeping thousands of Australian workmen employed. One lesson the war has taught is that Australians must make this country as self-contained as possible. Industries must be built up and supported in lieu of importing goods. Motorists can materially help by using Australian-made tyres. In this connection it is interesting to note that the recent Sydney deputation of rubber workers to Mr Tudor. Minister of Customs, asked for a duty of ICO per cent, on imported rubber goods. Such a tariff was net asked) for, nor is it desired by the leading manufacturers; but use is being made of the incident to influence Australian motorists, inference being made that tho con- ' snmers would have to pay. At the present time Australian-made tyres cost tho consumers less than the imported—a fact that is appreciated by most of our motorists. Such action is hardly likely to discourage | Australians from using Australian-made : goods. 1 The substitution of motor fire engines in I the Commonwealth capitals for the oldtime horse-drawn vehicles has been gradual, 1 but sure, and to-day the major part of the ; fire-fighting plant is petrol-driven. In Melj bourne alone" the approximate value of tho 1 motor engines, etc., is £26.000, and similar ; large amounts have been expended through- ! out the Commonwealth in modernising the fire brigades. THE ART OF DRIVING. With the evolution of the simple fixedgear motor cycle to the heavy three-speed ( side-car macHine have come cei-tain difficulties and complications in the art of driv-

ins. With the previous machine, when a hifi was encountered, tho throttle was opened wide, and beyond a certain amoiint ot juggling with the throttle and air-levers and ignition control, the motor cyclist could only trust that the machine would bo able to surmount at tho least the majority of the gradient, the remainder of the climb being as often as not carried out with a panting motor cyclist pushing alongside, the twospeed gear, with its great reduction from top to low, does not present many duvmg difficulties. The engine is kept on top gear for, as long as possible, owing to the tact that the speed when on low gear falls oil eo greatly. With a three-speed gear-box, however, an entirely n&w set of complications arises, and to get the best results out of a machine, and especially a heavy sidecar machine, the outfit must be driven more or less as one drives a car. . Undoubtedly the commonest mistake made in gear-changing on a motor cycle is to hold on to the top gear too long, or, in other words, until tho speed of the machine has become very low. The middle gear then has to be requisitioned with the outfit hardly moving, and consequently the rcduction to middle gear is not great enough to allow the engine to pull the outfit up the gradient; consequently the low gear has to be engaged far earlier than it is really necessary. . Gear-changing is considerably simptiliea for the beginner when a speedometer is fitted. On many machines it will bo found that a speed of 25 to 30 miles per borncan be obtained on middle gear without tho engine racing or vibrating unduly. It stands to reason, therefore, that when on a gradient with top gear engaged, there is no necessity to allow the machine to labour on this ratio when by changing down the same speed can be attained. Almost exactly the same argument applies to the low gear, although this can hardly be said to be exactly the same, owing to tho fact that low gear is a good deal lower in relation to tho middle gear than tho middle is to the top.

LIGHTING OF VEHICLES.

The Lights on Vehicles Bill, or, to give it its full name, “An Act to render compulsory tho carrying of lights on vehicles at night,’ is, it is understood, now law. It commences: “Subject to the provisions of this Act, every person who causes or permits any vehicle to be in any public highway during the period between half an hour after sunset and half an hour before sunrise shall provide that vehicle with a lamp or lamps in proper working order, and so constructed and capable of being so attached as when lighted to display to the front and rear a light visible for a reasonable distance, and so that the light to the front shall be a white light. “If only one lamp is so provided, it shall be placed on the off or right side_ of the vehicle. Every person diyving or being in charge of any vehicle in any public highway during the period aforesaid shall keep the lamp or lamps so provided properly trimmed, lighted, and attached. In providing such light care must be taken that the light exhibited shall not be of such dazzling brilliancy that it will affect the vision of drivers of vehicles approaching from the opposite direction. “Every person who offends against any of tho provisions of this section is liable to a fine of £l, and in tho case of a second or subsequent conviction to a fine of J 63: provided that if a person driving or being m charge of a vehicle is charged with an cffcnce under this section he shall not be convicted thereof if he proves to the satisfaction of the court that he was placed in charge of tho vehicle at a time or place when or where it was impossible to procure a lamp or lamps, and that ho had r.o subsequent opportunity of procuring such lamp or lamps, or that tho offence arose through the neglect or default of some other person whose duty it was to provide the vehicle with a lamp or lamps. “A local authority may make by-laws providing for the exemption from the aperation of this Act of any vehicle while engaged in carrying any inflammable goods of a kind specified in the by-law. This ct applies to every kind of vehicle except amy vehicle drawn or propelled by band. This Act applies to any machine or implement of any kind drawn or propelled by animal or mechanical traction in the same manner as it applies to vehicles. In tho case of a bicycle, tricycle, or other similar machine where only one lamp is provided, the provisions of this Act as to the position of the lamp shall not apply.’’