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).
Testing a Bentley's oversteering issue by adjusting tyre pressures and fitting different wheels and tyres.
Identifier | ExFiles\Box 89\4\ scan0274 | |
Date | 22th February 1938 | |
To. Rm.{William Robotham - Chief Engineer} CHATEAUROUX I/.22.2.38. Thank you for the copy of your report to Sg.{Arthur F. Sidgreaves - MD} which I have digested as a guide to the general outlook on the jobs. We carried out a series of tests on Sr's Bentley and found nothing whatsoever the matter with the steering mechanism or chassis, the trouble complained of being the usual Bentley oversteering characteristic aggravated by slightly under-inflated rear tyres. With 30 lbs/sq" (cold) front and rear as instructed, the behaviour of the car was no worse than standard. By increasing the rear tyre pressures to 35 lbs/sq", the oversteering could be reduced to manageable proport-ions but the ride became more harsh. We have in the past found and reported that on Bentleys with standard wheels and tyres, 35 lbs/sq" is required at the rear to make the cars manageable at high speeds. This would not have applied on Sr's last car as it had ultra light coachwork. We then fitted the 6.50 x 17 tyres and wheels off 6.B.IV. for Sr. to try on his car and he found and agreed that this entirely overcame his complaint. They did however make the steering rather heavy at low speeds without the Wraith type box, and there was also a slightly greater tendency towards low speed wobbles. ---------- Rm{William Robotham - Chief Engineer}/IMW.{Ivan M. Waller - Head of Chateauroux} Ivanho. Waller. | ||