From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Letter from G.E.T. Eyston discussing suspension and tyre wear issues on land speed record cars.
| Identifier | ExFiles\Box 170\3\ img098 | |
| Date | 21th September 1936 | |
| copy G.E.T. Eyston, 16, Hanover Road, N.W.10. 21st September, 1936. E.W. Hives Esq., Messrs. Rolls-Royce Ltd., DERBY. Dear Mr. Hives, Suspension. (a) 'Speed of the Wind' (b) 300 m.p.h. car. (a) The problem is to avoid undue wear of the near side front tyre when using a circle 10 miles in circumference - Wheelbase of car ......... 10' 11" Track ................ 5' 0" Front. 4'6" Rear. Dynamic diameter of tyres at 175 m.p.h - 39" approx. The car has front wheel drive. The pressure in the offside front tyre when running was 78 lbs, but by deflating the near side front tyres to 72 lbs the excessive wear on the nearside of the tread was transformed into equal wear all over. At an average speed of 158 m.p.h. the nearside tread only lasted 1 hour 40 minutes even at a pressure of 70/72 lbs; below which it was not thought advisable to go. I am examining the tyres at Fort Dunlop today, but unless you hear immediately to the contrary it is thought that the front of the car was tilting outwards allowing nearside front cover to spin. The cure would be a solid axle fitted if possible with free wheel device on each sideshaft to cater for a burst tyre. I cannot decrease the weight of the car on the front axle, which is about 3,300 lbs. The suspension front and rear is arranged as per the attached prints. For all practical purposes there is constant track in both cases. | ||