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).
Modifications to the design of SS & India spare wheel carriers.
| Identifier | WestWitteringFiles\T\January1929-February1929\ Scan164 | |
| Date | 19th February 1929 | |
| HS.{Lord Ernest Hives - Chair} FROM DA.{Bernard Day - Chassis Design} SECRET. ORIGINAL. DA{Bernard Day - Chassis Design}4/M19.2.29. SS.{S. Smith} & INDIA SPARE WHEEL CARRIERS. X7600 X5600 Replying to HS{Lord Ernest Hives - Chair}/AJL1/LG12229., referring to the modifications to N. sch.2760:- (a) We have investigated the question of withdrawing the 2nd. wheel and we cannot see the difficulties described. It appears to us that with the amount of parallel portion shewn on N. sch. 2760. it should be possible to withdraw the wheel. We presume however that you have determined by several trials that it cannot be done, and if this is so, we have no objection to modifying the aluminium bracket. We do not think it will be well to reduce the parallel portion to the extent shewn on your print as we think it will make the mounting of the wheel very inconvenient. We suggest instead that you should have a shorter parallel portion somewhat reduced in dia. with a steeper cone as indicated in pencil on the print. We do not think you ought to omit the lead in for the second hub. (b) We also find it rather difficult to believe that sufficient force can be exerted by the small handle to distort the steel cone piece. If it really is so however we have no objection to the cone being made straight instead of curved as indicated in pencil. If this is not sufficient the rim of the cone could be slightly thickened. (c) We suggest that a recess should be formed in the small handle so that when it contacts with the ring it cannot push it out. We have indicated this in pencil. (d) With reference to the clearances we certainly agree that these should be made as wide as is necessary. (e) We agree to the engraving of the lock and release positions on the bracket pin. We also agree to the peg working in the 90° slot. (f) The hinged number plate was R's proposal. We are not prepared to say that the design of the hinge and lock cannot be made simpler and more self protecting by going over the design again, but no doubt if it could be eliminated it would make the better job. It would be possible to use a fixed bar for carrying the number plate if we modified the rear dummy hub in the manner sketched in pencil on the print so that the stud carries the rear end of the rear wheel. We suggest that Derby might like to roughly lay this out and try it. You are of course aware that the whole of this rear wheel design is in the balance; both R.{Sir Henry Royce} and SG.{Arthur F. Sidgreaves - MD} wish to be able to take one wheel off and leave it in the garage, only replacing it when starting out on a long journey. This will necessitate considerable revision in the whole design. DA.{Bernard Day - Chassis Design} Print retained B.Y/F | ||