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).
The rear springing and tyres of the 7-EX R&S car at Le Canadel, suggesting improvements with semi-balloon tyres and hydraulic shock dampers.
| Identifier | ExFiles\Box 47\1\ Scan248 | |
| Date | 4th February 1926 | |
| Hs.{Lord Ernest Hives - Chair} To BY.{R.W. Bailey - Chief Engineer} } FROM R.{Sir Henry Royce} DA.{Bernard Day - Chassis Design} } LE CANADELHenry Royce's French residence. c. to CJ. BJ. RG.{Mr Rowledge} +4117 R1.AM4.2.26. RE. REAR SPRINGING - TYRES. X. 8410 X. 457 X. 8992 X. 8820 X. 4117 X. 235 7-EX R&S CAR AT LE CANADELHenry Royce's French residence. I find the springing on this as sent out, to be the best possible. Anymore flexible springs will allow it to bump because it is down quite to the limit with average load. My bad impression was due to bad roads. I have now tested Mr. Minchin's car which called here. This has the same springs, with a smaller and lighter body, and ordinary sized tyres. It does not ride nearly as comfortably as my car. There is nothing to be done except to see that all cars delivered have the most flexible springs possible, just to prevent too frequent bumpings on the rubber buffers, then use the shock dampers sufficiently tightly adjusted to prevent excessive rebound (and unsteadiness.) We hope for improvements by using semi-balloon tyres (which should be recommended at once, pointing out the difficulties of supplies). They are well worth the trouble. I would not be without them on these roads for any disadvantages I can see. We have purposely run them at 35 lbs. per sq.in., and up to 74 m.p.h. without signs of wobbles. In future we hope for advantages by the use of hydraulic shock dampers - urgently needed for both front and back axles! R.{Sir Henry Royce} [Watermark: CROXLEY] | ||