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).
New tyre models from the Dunlop Rubber Co.
| Identifier | ExFiles\Box 65\2\ scan0289 | |
| Date | 1st September 1928 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to SG.{Arthur F. Sidgreaves - MD} x7820 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}3/LG25. 9.28. DUNLOP RUBBER CO. x4050 x7820 x5820 x8005 x2446 We visited the Dunlop Rubber Co. on the 24th. inst. We discussed with them the question of tyres. Their opinion at present is that the 6.75" tyre for the 40/50 and 6" tyre for the 20 HP. which we are using as standard are too susceptible to variations in tyre pressure. To overcome this they have strengthened up the casing of both tyres, the modified samples of which they term 'Fort' models. Unfortunately, in doing so, they have increased the effective rolling radius of the tyres by about .250 / .375" and the weight by 6 lbs. or so per tyre, the cost of the tyre having gone up proportionately. We propose to try these tyres, but except for Colonial and Continental conditions it seems questionable whether they are really necessary. In addition to the 'Fort' series, the Dunlop Co. are introducing a still heavier tyre termed the 'Super' model. This might prove of interest in India where Rolls-Royce cars are used for hunting and so far balloon tyres have proved too vulnerable for cross-country work. In connection with the 'Super' tyre, it is interesting to note that on a 20" rim its rolling dia. is only very slightly less than our present std. 6.75" tyre on 21" rims. One point which we wish to determine is whether the 'Fort' and 'Super' tyres on the 21" rims will contd... | ||