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).
Performance of new 'Silent Tyres' on a Phantom III, noting that reduced tyre noise accentuates other chassis noises.
| Identifier | ExFiles\Box 157\2\ scan0131 | |
| Date | 18th February 1937 | |
| [Handwritten top center] RBax Mr Keys for what action please [Handwritten top right] 133 2 ? [Typed top left box] S/W. H.R. c.c. to Sg.{Arthur F. Sidgreaves - MD} c. " Rm.{William Robotham - Chief Engineer} c. " B. c. " S. [Typed top right] Cx{Major Len W. Cox - Advertising Manager}20/KW18.2.37. [Typed title] Silent Tyres - Phantom III. [Typed body] I have now had an opportunity of trying these tyres on our P.III Touring Limousine 3-AZ-38. Speaking generally there is not a lot of difference bearing in mind that the car with its present tyres has discs on the wheels, whereas I tried the new tyres on wheels without discs, but what difference there is definitely in favour of the new tyres. In the case of 3-AZ-38 the chassis noises are not so prominently in evidence by reason of the greater silence of the tyres as they are on 3-AZ-22, for in this latter case the more silent tyres have the effect of showing up more readily the noises of the chassis, which may as you says, be exhaust and/or transmission. [Handwritten] Rm{William Robotham - Chief Engineer} Whilst I should like, therefore, to be able to say that the Trials Cars with these new tyres are altogether better than the previous pattern - which is the opinion you have formed as the result of your tests around Derby - I cannot I am afraid be quite so definite as that because of the above mentioned features. We are proposing therefore to use a set of the new tyres on 3-AZ-38 at once, so as to get some experience with them after mileage, but do not propose at the moment to use them on 3-AZ-22 because I am of the opinion that the car is definitely no better with them, in fact, as I previously reported, the chassis noises seem rather more audible. If you can do anything to eliminate the transmission groan and exhaust noise, or a combination of the two, on this car we might be able to obtain more benefit from the silent tyres. [Typed closing] Cx.{Major Len W. Cox - Advertising Manager} | ||