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).
Observations and potential solutions for front wheel wobble on cars with front brakes.
| Identifier | ExFiles\Box 29\1\ Scan192 | |
| Date | 22th February 1926 guessed | |
| C O P Y. To Hs.{Lord Ernest Hives - Chair} from OY. RE. FRONT WHEEL WOBBLE. Mr. John Warren Watson of the "Stabilator" Co. mentioned some interesting points in experimental work he is doing in connection with wheel wobble on cars with front brakes. Every front-brake car in the U.S. fits balloon or semi-balloon tyres as standard equipment. Every one of them suffers from high speed wheel wobble. Nash now fit a friction shock absorber almost exactly like our reaction dampers, at the joint between the cross steering tube and the steering levers. (Nash uses vertical pivots and pin joints - not ball joints.) Packard now balance their disc wheels. (Presumably with a standard allowance for the weight of the tyre valve. I can see no actual balance weights such as we use for the individual tyres). Watson says the most fruitful thing he has done is to cancel the toe-in of the front wheels, keeping this between zero and 1/16" maximum. His theory is that with the increased compressibility of balloon tyres and the increased moment of inertia of the front axle, a "tramping" action occurs in the front axle at certain speeds. When this is coupled with a considerable toe-in of the front wheels, the wheel which is momentarily pressed against the ground tries to run across in front of the car. This "precesses" the gyroscope and gives the necessary alternate impulses to the system to increases both the tramping effect and the accompanying wobble. Whatever the explanation he says that reducing the toe-in to almost zero not only cancels the wobble in every case, but actually reduces the wear on the front tyres. I think you will probably want to try this if you have not done so already. OY. | ||