Bisbee daily review., 1921-03-20
WHY TO CAMbER 'ANO II TUE IN
 WHEELS IS TOLD

The reasons for camberins and
 toelng Tn wheels are not very well
 unuerstood by the average automu- ] ole man Tor that matter there are
 many engineers who cannot give sat
 isIactory explanations of the matter. camper means that the wheels are closer together at the bottom than
 dt the top and the slant is not usu-
 airy more than 2 deg, or about ? 3-S ln- for 3f in. wheels. Toe-in. means
 that the wheels are nearer together aI the front than at the rear this is also known as gather. The amount varies from Is in. to 1-2 in, the cor rect figure for most cars being IA in wheels are cambered in order to make steering easier If it were DOS slole to make the extended axis Of
 me king pin coincide with the ground then. when the wheel was turned
 side to side it would pivot about the king, pin and consequently there would be practically no sliding mo,
 ton under any circumstances. Ir order to accomplish this, however. II would be necessary to slant the wheel a great deal if the ordinary axle construction was used, couse-
 ouently in practice the slant is modi- fled. A method which has been ein- ployed occasionally is to mount the king pin in the wheel. In this ease, the wheel can he without camber.
 Wheel Resembles Com
 Any one who has watched a coin roll over the floor. must realize that when the wheel is slanted, the path is not straight ahead but in an out ward circle. This is the natural
 path for the tire, but instead it is forced straight ahead, consequently, there must be slippaGe between the tire surface and the road surface and wear must result.
 1t is clear that the only way to straignteh out the path of the coin is to steer it in the opposite direc tion in which it is running, in other words toe it in If this is done to the tire the strain due to its natural ten dency to run in a circle is remOveul and there is no wear because of this effect. It is hardly necessary to add that this is exactly what is accnm plished when the wheels are toed-in. It is also necessary to allow a certain amount of camber and roe in due to play in the bearings and steering nc chanism. This is added to that a.! lowed fer easy steering. It may or may not be necessary to allow any camter to compensate for play III the bearings inssmuch as the load oil the wheels. is practically constant and thus the force which tends to spread them apart at the bottom and bring them together at the top $ COI;-1u:. However. wesT in the wheel bearings or king bolt buskings will cause the wheels to sp'cs a; the bottom and this must ts counIeracted 5y little extra camber.
 Wheel Action
 When the car is driving forward. 1, the tesdency is for the wheels to come together at the rear. Any wear in the wheel bearings, in the king bolt. or in the tie-rod bushinss will tend to counteract the effect of the toe in and thie wear must be provid- ed for by increasing the toe-in slight amount so that the wear takes place. the wheels will not be too ! nearly parallel.
 It is often said that wheels are cam ! bered and toed-in on automobiles for | the same reasons that it is done on | carriages, but this not usually thel case inasmuch as a Carriage has | conical axle spindle. The wheel will l attempt to slide out on the spindle | causing wear and friction on the re- taining nut. To overcome this diff | culty, the axle spindle is bent down | so that it's lowest surface is parallel with the roadway. In order that the | spokes may be perpendicular to the | surface. and thus have greater ef- fectiye strength, it is necessary 10 | dish the wheels Also on account of the conical axle spindles. it is neces- sary to toe-in the wheels. If the | wheels were not dished it would be necessary to toe them in anyhow to | the effect of the camber |
 Inasmuch as automobiles do not em rIoy conical spindles. these reasons | do not hold in automobile construc- ] ton. Whenever conical bearings are !, used in automobile wheels any axial | thrust is neutralized by having two bearings set in opposite directions i
 According to Frank Thayer. who has a garage at Lowell. it is a good | idea to have wheels examined at reg l ular intervals, and, If they are out | of line. to have them adjusted, thus | saing time, trouble and money.