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 detailing the results of tests on tire friction and steering torque on various road surfaces.
| Identifier | ExFiles\Box 154\3\ scan0039 | |
| Date | 15th September 1927 | |
| ROLLS-ROYCE OF AMERICA, INC. SPRINGFIELD, MASS. X-3682 OYI/R/91327 September 15th, 1927. Mr. E.W. Hives, Rolls-Royce Ltd., Derby, England. Dear Mr. Hives: We are typing below for your information, a copy of a letter recently received from our Experimental Department. RE: STEERING "Test were made at Mr. Olley's order on the friction between a front tire and (a) Cold concrete (b) Hot concrete (c) A slippery surface approximating wet asphalt. A United States Cord Balloon tire with a 100" lever was used in the tests. The tire was inflated to 35 lbs. per sq. in. and carried a load of 1300 lbs. The results were :- Surface Load Pull on 100" lever Torque Cold concrete 1300# 18# 1800 in. lbs. Hot concrete 1300# 20# 2000 in. lbs. Slippering road 1300# 8# 800 in. lbs. In the second test - hot concrete -, the tire was hot at the point of contact, but not elsewhere. In running conditions the tire would be hot and the pressure slightly increased, this would decrease the necessary torque. This would indicate that the difference in friction on hot and cold concrete is not great." Very truly yours, Maurice Olley MO/R | ||