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MOTORS AND MOTOR-DRIVING

Michelin, to be imported into the United Kingdom under licence, as the 'Clipper-Michelin,' and it at once became the standard type of pneumatic tyre among British users.


THE CHOICE OF A TYRE

Assuming that the reader is purchasing a car for the first time, he may reasonably specify the fitting of Clipper-Michelin tyres and leave experimenting, if so inclined, until a later date. This type of tyre is taken as a standard for purposes of description and illustration of the processes of repair.[1] Several items, however, require previous consideration. It is more than likely that though the right make of tyre be chosen the novice may go wrong as to certain points of detail. In the first place it is of the highest importance that the diameters should be correctly apportioned to the weight, and secondly, whatever the size of cover, that it should be of the correct degree of substance. Thirdly, it is advantageous that all the wheels should be of equal size.

As regards diameters, it may be stated that the Michelin tyre is made in various sizes, ranging from fifty-five to one hundred and twenty millimetres, or two and a half inches to four and three-quarter inches. The tendency of makers is to fit too small a diameter, and in most cases it is safe to ask for one size larger than that which is offered. In the 'Guide Michelin,' however, a complete table is provided in which the suitable diameters for given weights are specified, together with the degree of inflation to be allowed, and these data should be studied with due care. The 'Guide,' a most useful volume of 575 pages, is included with the Michelin repair outfits, or may be obtained gratuitously from the firm. With regard to substance, the covers are of three types, the léger, the renforcé, and the extra-fort. The first-named may be discarded altogether, the second fitted to the front wheels if the

  1. Figures 1 to 16 have been selected by permission from the excellent Guide Michelin and redrawn, in some cases with slight emendations.