WHEEL WOBBLE

Sun (Auckland), Volume 1, Issue 88, 5 July 1927, Page 12

WHEEL WOBBLE

AND A REMEDY

“Wheel wobble” is an expressivi term describing a trouble which many motorists have experienced and mart have heard about, but which may be a new thing to the hundreds of peopl* who are now taking delivery of the: first cars.

The disease existed before the day? of balloon tyres—in fact, I remember a Ford which was peculiarly addvtei to developing a fit of uncontrollabilitr at about 25 miles an hour. Although the first experience of wheel wobbk on this Ford was rather embarrassing we soon found that by accelerating a quickly as possible to a speed in ex cess of the critical one the trouble was either non-existent or negligible But when the steering wheel of a ear starts oscillating in one’s hands anc gives more and more powerful tugthe harder one tries to check it, a good deal of pluck is required to “step on the gas” instead of on the brake THE SECRET That, however, is the secret— eithe: go more quickly or more slowly, buanyway, get away from the critic* speed as rapidly as possible before th< oscillations at the front wheels an steering wheel have time to build up into a serious movement. And it usually means going faster, since to slow down means going too slowly fo: convenience. A variety of things may render ? car subject to wheel wobble, faulty steering machanism being a generic description, but as the majority ol these causes are probably beyond the beginner’s diagnosing, and certainly beyond his curing, I will limit myseli to the simplest and most likely one. This is incorrect inflation of balloop. tyres. It has to be realised that while these low pressure tyres give oat greatly increased comfort, they need a lot more accurate attention in the matter of inflation pressure than the old “board hard” type. So long as the latter were really hard, and showed little spreading on the road when th' car was loaded, it did not matter much what the pressure was. But with balloons a pound or so one way or the other is a serious matter. Not only wheel wobble, but heavy steering and undue petrol consumption are amony the possible results, not to mention undue wear of the car if the tyres are too hard, and of the tyres themselves if they are too soft. POINTS OF PRESSURE And it is not merely that all the tyres must be kept pumped to a predetermined pressure, .\ctually the best pressure may be different for each the four wheels of any given car; while the varying load—the difference to weight between the driver only an ( the complement of driver and feur passengers — really ought to be provided for. Still, I do not want to make the of balloon tyres seem a more laborioa* matter than it really is, and if the beginner makes sure that the four tyres are pumped to the pressure recommended by the tyre makers, he will not usually be far wrong, so long' bb, b) constant testing with a properly sensitive balloon tyre gauge, he sees that the correct pressure is maintainedAnd if this course does not prove entirely satisfactory a little experiment with each individual tyre will soon show what variation from the average gives the best results. That does not dispose of the question of wheel wobble, however. Tb ir may develop even though the P res ' sures are quite correctly maintain# after painstaking experiment to arrrw at the best figures, and simply provethat compromise is necessary. KEEP COOL The important thing when the iron wheels first seem to be getting out o. control is to keep cool and either slo* down or speed up immediately and af rapidly as your car’s power* of deceleration or acceleration will permit. If you choose tn former, as you probably will the m** time, do not forget in the heat of to moment that there may be a car behind. Hospital is a pool place m which to reflect on the surprising power of modern four-wheel brakesand even if you like it the occupaniof the other car may not be able spare the time. . . At the first opportunity, try the front tyres an extra pound eae ■ and deliberately seek for the speed which the wheels begin to wobble. may have cured the tendency time, or you may find that hig» pressure makes matters worse. A«' way, it is possible to cure wheel vrol)t ? by this method, or, at least, to raise rot critical speed at which the trouble <Develops to a, point beyond that w ftl . the car can reach, which amounts the same thing. hr Finally, if you are not successful w juggling with your tyre pressures, * is obvious that some more scrlo o f mechanical defect is at the bottom the trouble, and you should consw the agent from whom the car was P chased.