MOTOR AND CYCLE.

Taranaki Daily News, 9 April 1921, Page 11

MOTOR AND CYCLE.

NEWS AND NOTES. DEFECTIVE BRAKES. Many modern cars, in which one might reasonably expect to find the most progressive features are lamentably deficient in many points of design. It is quite true that the' defects in mind are not at all obvious when the car is running; and neither do they appear particularly glaring when the bare chassis is examined prior to purchase. But the unfortunate owner becomes painfully aware of their presence immediately any repairs are contemplated. One naturally expects that when a pair of side brakes fail to fulfil their normal duties and ordinary adjustment does not put matters right, a few hours work at the most should suffice to re-line the brake shoes and put the vehicle in action again. With certain types of brakes, howevet, more particularly those constructed on the internal expanding principle, a series of obstacles confront the repairer; and when the job is eventually finished, the car owner receives a shock caused by the length of the bill. If really good design were adopted, the operation .of re-lining a pair of brakes could be performed quite easily by a chaffeur during a halt for lunch, or before setting out on a day’s run by the owner, himself if no chauffeur is there. What actually happens, unfortunately, is quite a different story. First of all the rear wheels have to be removed, together with the hubs'—and how few motorists are provident enough to include a wheel-drawer in their tool kits? More often than not this operation occupies quite a long time, and if the drum has developed a ridge, the shoes foul the latter, even when the wheel is ready to be drawn. What practical motorist is unmindful of strenuous struggles in endeavoring to remove rear hubs'—and yet why in the name of fortune should the job be made so difficult by our arch enemy, the nonpractical designer? Then, again, the lining material has to be removed by punching out numerous rivets, which cannot be done without a vise; but very little intelligence is necessary to devise a method of securing lirake linings capable of being fitted and remaining secure without all this trouble.

In addition to all these objections we find that brake cam spindles are usually arranged in such a way that they seldom receive an adequate amount of lubricant, and a further difficulty arises in view of these parts having become seized in the bearings. There are many designs of rear brakes, the repair of which entails the car being out of service for at least one whole day, and if things happen to go a wkwardly, this length of time may etan 1 a chance of becoming doubled Ease of brake adjustment is one thing, and is generally well thought out, but the perfect brake should be capable of repair with but very little more trouble. GEAR RATIOS. Before the war there was a distinct tendency among light manufacturers to reduce gear ratios, in order to improve the hill-climbing and top-speed abilities of their productions. Some of them went rather too far in this direction, with the result that in one or two cases the engine had to turn at 1000 revolutions per minute to attain a road speed on top gear of fifteen miles per hour. Apparently such makers have appreciated the fact that they made the gear ratios of the pre-war cars too low, and they have commenced to move in the opposite direction; but some would appear to have- gone too fgr already in raising the gears. For their two-seater models, perhaps, the higher gear ratios are quite satisfactory, giving a road speed of twenty-two miles or So per hour at 1000 revolutions per minute; but these same chassis, when fitted with light four-seated bodies, are distinctly over-geared, and the use of the great level is called for with somewhat annoying frequency in other than comparatively flat districts.

CAUSE OF CAR BREAKDOWN. The Royal Automobile Club of England has for the past twelve months conducted a “Get You Home” road campaign which renders first aid to motorists stranded on the roadside owing to mechanical troubles. Statistics compiled on the assistance rendered during 1920 afford an interesting and instructive insight as to the causes of car breakdowns whilst the automobile is in use:— Analysis of cases dealt with during the year 1920: Per cent. Power Unit — Cylinders and pistons ....... 3.9 Valves 9-® Valve mechanism 2.1 Crankshafts »-s-s 1.8 Lubrication 7.5 Ignition 13.4 Carburation 3.4 Water circulation 1-9 Starting mechanism 0.5 Not stated 4.5 39.6 Transmission— Clutch 5.1 Gear Box* 5.2 Couplings, universal joints & propeller shaft 7.5 Back Axle Shafts 13.9 Differential 4.0 Bevels and worms 2.2 37.9 Front axle and steering 5.1 Road wheels, suspension & brakes 7.8 Electric lighting failures .... 0.8 Accidents 8.8 100.0 While these figures show unmistakably the parts of the car which are most susceptible to breakdown, it must be remembered that the average car runs thousands of miles without an involuntary stop of any kind-