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 America to Mr. F.H. Royce concerning high-speed wobbles, gyroscopic couple and tire design.
| Identifier | ExFiles\Box 29\1\ Scan205 | |
| Date | 28th February 1926 | |
| COPY. ROLLS-ROYCE OF AMERICA, INC. SPRINGFIELD, MASS. Cyl-M-22-26. February 28, 1926. Mr. Claude Johnson, Rolls-Royce, Ltd., London, England. (Copy for attention of Mr. F.H. Royce). Dear Sir: Re: High speed wobbles. We think that Mr. Royce may be interested in the attached print on which we have shown the theoretical gyroscopic couple due to 'tramping', as observed in high speed wobble. We have assumed that the wobble occurs at 60 m.p.h. and that the track left on the road shows that the wheel turns from 5° inward inclination to 5° outward inclination in 3 feet. The corresponding gyrostatic couple we find to be the equivalent of 380 lbs. at each wheel. We also offer a suggestion why round tread tires of the Dunlop type are observed to run in a curve when they strike the road at an angle, while this effect is apparently less with the United States tires which have an almost flat tread. Scalloping at the edges is also found to be less with the U.S. than with the Dunlop tires, for the same reason. Yours very truly, (Sgd) Maurice Olley. MO/J.S. | ||