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).
Inaccuracies, weight, and design concerns of Michelin disc wheels.
| Identifier | ExFiles\Box 181\M11\ img234 | |
| Date | 24th September 1919 | |
| To EH. from R.{Sir Henry Royce} Copy to CJ. " " BM. " " DA.{Bernard Day - Chassis Design} " " G.{Mr Griffiths - Chief Accountant / Mr Gnapp} " " PN.{Mr Northey} " " RN.{Mr Robinson} ORIGINAL 1919 RECEIVED RE MICHELIN DISC WHEELS. <3482 X.682 I am astounded to hear that the holes in the Michelin wheels are inaccurate to the extent of .100". I quite agree with you not upsetting 1 EX. with anything but adopted standard parts, and suggest therefore fitting the Michelin wheels to another chassis such as 7 CA, or preferably something with unsatisfactory present arrangement. I consider you ought not to be too particular about the accuracy of spacing because Michelin wheels have been running for many years very satisfactorily, for instance, all Lancia belonging to the navy. _2651 In comparing the weight, it would appear that our details for the Michelin wheels are unnecessarily heavy, 9% difference in the actual wheel amounting to 3.3 lbs is not much, especially as it should have permitted some weight saving on the hub. It would also be necessary, to make a fair comparison, to include the double disc covers and their fixings, as arranged on 49 GB. While discussing this subject, I strongly object to the Rudge-Whitworth pattern of cover, because it stands out such a long way beyond the tyre, and secondly, it appears to be downright ugly. The sketch hereunder shews the dimensions and the danger of forgetting these projections exist. I am always anxious in passing another vehicle or shunting, that this 3 1/2" projection may catch a similar projection on a passing car. (Contd.) No. 227 C.S.D. of B. 24th Sept. 1919. A.G.Elliot | ||