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).
Service bulletin discussing the causes of tire wear, specifically scalloping on non-skid treads.
| Identifier | ExFiles\Box 42\5\ Scan043 | |
| Date | 10th October 1925 | |
| OY2-E-101025 To: Mr. Southern (S) CC: Messrs. Nadin - Caswell Bagnall - Harkness Hulley - Belnap Southern - Beaver From: Mr. Olley MATERIAL FOR SERVICE BULLETIN Re: Tire wear This matter was discussed with representatives of the Goodrich Company - Mr. Moore and Mr. Montgomery. Two cases of wear were discussed, namely - 1. Scalloping of rear tires producing noise 2. Wear of right front tires. 1. This is an extreme case of the wear which occurs very generally on both front and rear wheels with Goodrich, Goodyear or any form of non-skid treads. We do actually find such wear or "scalloping" on every form of non-skid tread we use, especially on front wheels where there is a certain amount of slack in the steering. It is believed to be due to the fact that at different points in the tread there is a sudden change in the quantity of rubber supporting the maximum load, for instance, when the bar of the Goodrich H is at the bottom there is far more rubber to carry the load than when the points of the H are at the bottom. The result is that these weak sections, suddenly loaded, move sideways on the road and wear more rapidly than the rest of the tire. Every maker is therefore attempting to make a non-skid tread in which the amount of rubber in contact with the road is constant at all sections. The new Goodyear ribbed diamond tread is one attempt, and the new Goodrich tread in which the bars are square instead of rounded is another. Scalloping still occurs however and complaints of noise from non-skid treads which have worn scallops are fairly general on all makes of cars. It is believed by the makers that the complaints occur more generally when tires are under inflated, and more generally on good roads (hard macadam and particularly concrete) than on dirt roads. There is no cure for the trouble with existing treads. Maintaining adequate air pressure in the tires will help. | ||