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 comparison memo between Michelin Comfort Bibendum and Dunlop tyres.
| Identifier | ExFiles\Box 45\2\ Scan045 | |
| Date | 29th November 1927 | |
| X4050 x987 To Hs.{Lord Ernest Hives - Chair} from GWH.{George W. Hancock - Head Chateauroux} Hs{Lord Ernest Hives - Chair}/GWH{George W. Hancock - Head Chateauroux}/LG29.11.27. RE. MICHELIN COMFORT BIBENDUM TYRES. 17 X 50. These tyres are worse for periods and groans at low speeds than Dunlops. At speeds over 30 m.p.h. they are definitely quieter, the note from the tyres is of a lower tone. They are not so good for skidding qualities, and at speeds, give one the impression of deflated tyres. The effective circumference of these tyres is as below - comparison taken with Dunlops. Michelin, 17 X 50. lbs./sq. in. effective cir: 50 101 5/8" 45 100 3/8" 40 100 1/2" 35 100 1/16" Dunlop 33 X 6.75" Lbs/sq.in. effective circumference. 50 105 5/16" 45 104 11/16" 40 104 1/4" 35 103 3/4" 30 103.2" Wt. on wheel - 1 ton. 4 cwts. Hs{Lord Ernest Hives - Chair}/G.W.Hancock. | ||