Motor Road Transport For Commercial Purposes
(Liquid Fuel, Steam, Electricity)

FUEL, SPARE PARTS, ETC. 151 (2) Another detriment is the present inability to protect adequately the walls of the cover from damage due to rimning against Street kerbs. (3) A point which is not so serious, but which. must not be overlooked, is that a mechanically or electrically operated pump must be used for inflation. Considerations of weight and price in contrast to existing types of solid tyres are of importance. In order to get a comparison that is a true one, it is necessary to contrast the respective weights of the fitted wheels, because not only should the weights of the tyres themselves come into the calculation, but also those of the various attachment fittings. More- over, the diameter of the actual wheels for the pneumatic is not equivalent to that for the solid tyre. Taking, as an example, fitted wheels suitable for a 3-ton lorry— Solid. No. of tyres : 6. Size : 1010 x 120 mm. Weight: 850 Ibs. Weight of 4 wheels : 750 Ibs. Total weight: 1,600 Ibs. (approx.). Pneumatic. No. of tyres : 4. Size : 38 X 7 ins., front; 44 X 10 ins., rear. Weight: 680 Ibs. Weight of 4 wheels : 550 Ibs. Total weight: 1,230 Ibs. It will be seen that, on the score of weight, the pneumatic is superior. The respective prices for sets of tyres are as follows— Solid. 6 tyres, 860 x 90 = ^36 6 tyres, 900 x 100 = ^42 6 tyres, 1010 x 120 = ^56 Pneumatic. 4 covers, 36 x 6 ins. 4 tubes, 36 x 6 ins. = £146 2 covers, 36 X 6 ins. 2 tubes, 36 X 6 ins. 2 covers, 40 X 8 ins. 2 tubes, 40 X 8 ins. = ^206 3 covers, 38 X 7 ins. 4 tubes, 38 x 7 ins. 5 covers, 42 X 9 ins. 2 tubes, 42 x 9 ins. = £278