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).
Study on excessive tire wear causes, including brake adjustment and misalignment, with a data table on estimated mileage in Detroit and Buffalo.
| Identifier | ExFiles\Box 45\2\ Scan076 | |
| Date | 1st December 1927 | |
| taneously by quick depression of the foot pedal; while on the road, under slighter depression, one wheel may take hold more than another. Four wheel brakes must be adjusted perfectly, so that no one tire will stand more than its normal share of braking. Two wheel brakes must also be properly adjusted, or one tire will take more strain and wear out faster than the other. In order to adjust brakes properly, it is necessary to use a scientific brake-adjusting machine, and this service is coming into vogue in all principal cities in the country, so that there is really no excuse for anyone driving with poorly adjusted brakes. Improper brake adjustment will throw more wear on one wheel or another, as the case may be. 8. MISALIGNMENT, Etc.—These conditions are fairly well known. They have been with us ever since the advent of automobiles, and, consequently, have been given a lot of study. The average operator knows misalignment wear by its varied appearance. It is mentioned only in this study as a reminder that mechanical derangement of the automobile will cause fast tread wear, and is in the same general category as other operating conditions referred to as new and recently developed reasons. In addition to these, there are other factors, perhaps of minor importance, but here and there prevalent. None of the conditions outlined are all prevalent at the same time fortunately, or a tire would give no mileage at all, but some of them are ever prevalent in a more or less degree, and sometimes one or more of them are quite severe. Consequently, there are cases where balloon tires will be worn down prematurely. The rate of wear on high pressure tires is practically the same, but high pressure tires have the tread concentrated in a smaller area, have a deeper tread design, less flexibility, and for that reason do not show the effect of these operating conditions as quickly. However, high pressure tires used under the same present-day conditions as balloon tires will show the same variation in wear. Under these circumstances, it is logical to recommend that all members of the Association take a firm stand, refusing to adjust tires failing from causes beyond the control of the manufacturer. The customer may not realise the automobile activity has increased, operating conditions have changed very greatly, people are driving much faster than ever before, and good roads plus organised traffic systems have put more strain on tires than ever before. From a tire wear standpoint, operating conditions are growing worse instead of better, making it apparent that the responsibility for excessive tire wear is really in the hands of the tire user. Therefore, the user should understand thoroughly the causes of excessive tire wear cited in this paper. December, 1927. TREAD WEAR IN DETROIT AND BUFFALO. Tire Tire Car Car Estimated Miles to Smooth. Make Size Make Model Buffalo. Detroit. "D" 28 x 4.40 ERSKINE COUPE 6,820 — "B" 29 x 4.40 CHEVROLET COUPE 9,170 10,160 "C" 29 x 4.40 CHEVROLET COUPE 9,360 — "A" 29 x 4.40 CHEVROLET SEDAN 11,040 — "B" 29 x 4.40 CHEVROLET SEDAN 10,360 — "B" 29 x 4.40 CHEVROLET SEDAN 7,440 — "B" 29 x 4.40 CHEVROLET SEDAN 6,080 — "B" 29 x 4.40 CHEVROLET COACH — — "A" 29 x 4.75 PONTIAC ROADSTER — 8,480 "E" 29 x 4.75 CHRYSLER COUPE — 8,990 "F" 29 x 4.75 OAKLAND SEDAN 10,000 5,900 "E" 30 x 5.00 DODGE SEDAN 8,400 — "A" 30 x 5.00 ESSEX COUPE — 9,300 "F" 30 x 5.00 ESSEX COACH 11,520 — "F" 31 x 5.00 ESSEX ROADSTER 10,830 — "A" 31 x 5.00 ESSEX COUPE — 1,080 "A" 31 x 5.00 ESSEX SEDAN — 11,450 "D" 31 x 5.00 PEERLESS SEDAN — 10,920 "F" 30 x 5.25 OAKLAND COUPE 9,600 — "H" 30 x 5.25 OAKLAND COUPE 9,860 — "A" 30 x 5.25 HUPMOBILE COUPE — 11,100 "C" 30 x 5.25 CHRYSLER ROADSTER — 10,400 "G" 30 x 5.25 OLDSMOBILE SEDAN 9,920 — "B" 31 x 5.25 BUICK COUPE 8,720 — "D" 31 x 5.25 BUICK COUPE — 7,144 "D" 31 x 5.25 STUDEBAKER COUPE 9,920 7,620 "B" 31 x 5.25 BUICK COUPE — 8,160 "B" 31 x 5.25 BUICK SEDAN 11,040 14,160 "E" 31 x 5.25 BUICK SEDAN — 9,000 "F" 31 x 5.25 BUICK SEDAN — 8,200 "D" 31 x 5.25 STUDEBAKER SEDAN — 7,960 "H" 29 x 5.50 DODGE SEDAN 13,440 — "H" 29 x 5.50 OAKLAND SEDAN 8,240 — "H" 29 x 5.50 OAKLAND COUPE 9,360 6,680 "B" 33 x 5.77 PACKARD ROADSTER 9,040 — "E" 30 x 6.00 CHRYSLER ROADSTER — 10,190 "E" 30 x 6.00 CHRYSLER SEDAN — 12,480 "E" 30 x 6.00 CHRYSLER SEDAN — 12,920 "A" 31 x 6.00 HUDSON COACH — 15,040 "D" 31 x 6.00 HUDSON SEDAN 9,600 — "D" 31 x 6.00 LA{L. A. Archer} SALLE SEDAN 10,880 — "F" 32 x 6.00 LA{L. A. Archer} SALLE SEDAN — 6,640 "A" 32 x 6.00 BUICK COUPE — 12,000 "B" 33 x 6.00 BUICK COUPE — 7,000 "D" 33 x 6.00 BUICK COUPE 6,960 6,900 "B" 33 x 6.00 BUICK COUPE — 9,840 "D" 33 x 6.00 BUICK COACH — 9,620 "D" 33 x 6.00 BUICK SEDAN — 9,920 "D" 33 x 6.00 BUICK COACH — 10,880 "D" 33 x 6.00 BUICK SEDAN — 12,880 "D" 33 x 6.00 BUICK SEDAN — 7,300 "A" 33 x 6.00 HUPMOBILE SEDAN 12,340 — "D" 33 x 6.00 NASH SEDAN 14,000 — "F" 33 x 6.75 GARDNER COUPE 9,200 — "A" 33 x 6.75 CADILLAC COUPE 13,820 13,760 "F" 33 x 6.75 CADILLAC COUPE 14,080 11,880 "A" 33 x 6.75 CADILLAC COACH — 7,160 Average Mileage ... 9,970 9,480 | ||