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).
Article discussing the pros, cons, and standardisation of balloon tyres, alongside advertisements for Daimler and Overland cars.
| Identifier | ExFiles\Box 53\2\ Scan100 | |
| Date | 8th March 1924 | |
| lii. COUNTRY LIFE. March 8th, 1924 on the hard side, then the balloon tyres might be expected to give no noticeable roll, but on a softly sprung car where rolling was only just avoided, or prevented by some special device as on the Lanchester —there is also an anti-rolling device on the Napier, of course—the story might be very different. The experiences of some of the makers of very softly sprung light cars, such as the Humber 8 h.p., Wolseley Ten or Horstman, would be illuminating in this connection. THE CONS. From this possible but indefinite argument against the tyre we may proceed to the definite limitations under which the tyres at present labour. Not the least of these follow directly from the improved road adhesion that is in other respects a distinct asset. First, then, the greater the road adhesion of the car the greater the power required to drive it; in other words, the balloon tyre will increase fuel consumption and reduce speed. Neither Bentley nor Napier experiments say anything about increased fuel consumption, and it is a safe assumption that in the case of cars with such a generous power reserve as have these two the speed capacity of the car would not be affected materially. But in the case of a smaller car with no great power reserve the ultimate speed of the car may be expected to be reduced by about 5 per cent., and the increase in fuel consumption would depend on the margin that existed between the speed at which the driver normally travelled and the maximum speed of which the car was capable. Also a resultant of the increased road adhesion of the larger tyres is the heavier steering that accompanies their use. At ordinary and at high speeds this would appear to be inappreciable, but at low speeds considerable more effort is required to turn the steering wheel through a given arc than would be required with tyres of normal size. The possibility of the tyres leaving the rim at undesired moments has already been touched upon and it is connected with the question of the type of rim used for the mounting of the tyres and this in turn involves the very important matter of standardisation. STANDARDISATION. It must be clearly understood that balloon tyres cannot be fitted to existing rims, irrespective of the relative sizes of the old tyres and of the balloons that will replace them. Anyone requiring balloon tyres must first of all obtain wheels with rims to take them, so that the conversion of an existing car is an expensive matter. But the fact that there are three different types of rims or wheels for balloon tyres from which a choice must be made is one of the strongest arguments existing against the development of the new tyres. The rim chosen in the first instance will determine the make of tyre that must be used and the only one that can be used while those wheels are on the car, and should a tyre (or two tyres if there be a spare) fail on the road another of the same make must be found to replace it. The three rims at present used are a modification of the existing beaded edge rim, the American straight-sided rim and a sort of compromise between the two known as the Dunlop double bead, the tyre for which has a pair of wires in its rim fitting, but the rim itself cannot be divided as can that for the genuine straight-sided tyre. It is on the ground of this absence of any standardisation that Mr. Lionel Rapson bases his objections to the new tyres. As the man who pioneered the principle that has been developed into these tyres—that of the employment of low pressures—and as one who has done so much to bring the pneumatic tyre to its present high pitch of development, Mr. Rapson cannot be stigmatised as an opponent of progress, nor is it likely that the winner of the Dewar Trophy by putting up a tyre record (over 40,000 miles) that had never previously been approached would be afraid of competition. Indeed, Mr. Rapson has announced his intention of entering the balloon tyre market as soon as some agreement is reached in the matter of rim and wheel sizes. In the meantime he has declined the challenge of Mr. Thomas Warwick, a pioneer of the new tyres, to a comparative R.A.C. test of Rapson and Almagam low pressure tyres. While somewhat surprised at the refusal of the challenge, we must say that we think Mr. Rapson is probably justified on the grounds that until standard rims are available there is little point in proving or testing the new tyres by public events. There is, however, a suggestion of inconsistency in his attitude in that he set the ball rolling by challenging the maker of a balloon tyre to submit a set for an R.A.C. trial of 40,000 miles, the cost of which he offered to defray if it were successful. Mr. Warwick took up the challenge in a modified form, suggesting a comparative trial of his “Ballonette” tyres against a set of Rapsons fitted to a similar car, the distance of the trial being for a first lap of 5,000 miles with subsequent additions by agreement. This is the challenge that has been refused, and there the matter rests for the present. There is, however, nothing to prevent any maker of balloon tyres from entering a set into an R.A.C. trial on his own initiative. It was at about the time of the last Olympia Show that Mr. Warwick announced his willingness to supply a set of four wheels and ballonette tyres for light cars at a price of £30 gs, on condition that if, after a month’s trial, the owner of them was dissatisfied he could return the set and have back 75 per cent. of what he had paid. This was certainly a very fair offer, carrying with it the weight of honest conviction, but we are not aware of what reception it received. ADVERTISEMENTS: Daimler Landaulettes & Limousines 21 h.p. 30 h.p. 45 h.p. CHASSIS - £700 950 1,225 LANDAULETTES £1,150 1,400 1,675 ENCLOSED ,, £1,275 1,525 1,800 Cars for the Owner to Drive 16 h.p. 20 h.p. 25 h.p. 35 h.p. CHASSIS - £450 550 650 900 OPEN CARS - £600 725 825 1,075 SALOONS - £650 775 875 1,125 BY APPOINTMENT Special Agents STRATTON-INSTONE Ltd. 27 PALL MALL, LONDON, S.W.1. Q.H.F.A. Overland 70% of this manufac BRITAIN in THE BRITISH BUILT Five-Seater De-Luxe £295 (ex Works) WILLYS OVERLAND C Factory and Sales Dept. : He London Showrooms : 151-1 London Service Depot : 111 | ||