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Show lk ALBERT L. CLOUGH Editor Motor Service Bureau I2evieu of Gavieufa m, wnat maices A Oar "Hard On Tires." d HE question is often asked "Why la a certain model of car easier t ft, m on ros tnan another of practically the same total -weight and I m with the same tire equipment." That there are such differences ia well known and a few statements bearing upon thia subject may not be out of place. It is plain that a Bpringless motor car, running on pneumatics, would 'eat up tires" at a prohibitive rate, for there ", would be nothing but the tires themselves to cushion road shocks and the full duty of absorbing them would fall upon the tires. Every bit J of the car weight would act to strike hammer "blows upon the tires, each t time the wheels encountered obstructions. In the case of an ordinary, jg spring suspended motor car, the springs cushion the blows which the "i chassis delivers to the axles and immensely reduce the stresses imposed upon the tires. In bo far as the springs are perfectly limber, the tires are relieved of their Bhock-absorblng duty and the Intensity of the 1 destructive stresses acting upon the structure of the tires, is reduced. M Differences in the spring action of different models may thus account, qj' to somo extent, for the variations In tire service which they show. I While the springs protect the tires from the uncushloned blows of & Pj major part of the weight they carry the weight of the axles, wheels, a pM. portion of the propeller shaft, and of the springs themselves, aa well as that of the transmission (in some designs) is not supported by the springs, acts aa "dead load" upon the tires and is known as "unsprung weight." The larger the proportion of this unsprung weight, to the total weight, the greater the destructive effect upon tires, other things being equal. A clutch which cannot be made to engage gently and t brakes which are prone to very sudden engagement that results in slipping the wheels; bad balance of the car which tends to make it side vi Blip at high Bpeeds or otherwise to "hold the road" imperfectly and a badly designed steering gear whioh keeps the front wheels "wobbling, J all tend to increase tire wear. IfflVfATVTi AIiLOWANCB FOR OTjD OAR. G. E. EL. writes: I have a 1913 . car whioh cost mo nearly tffl,00O, which I have been thinking: of turning in for a current model $ of the sazno make, but find that they -J ' will allow me but $400 tor it, al-" al-" thorajfli It la practically in aa good ft condition &s whn It was new. Isn't this an unreasonably small allowance allow-ance T Answer; In a way. It may bo bo, considerins that your car Lb probably prob-ably still capable of giving1 an Immense Im-mense amount of satisfactory service, serv-ice, but in another way it Is not, aa jmL yon couM not aret even as much aa lu ' this in the open market. So long as the mass of motorists value a B ear for Its "up to dateness" rather I than for its capacity of giving uao- . I ful ervloe and so long as so many I of them still buy new cars yearly, I the used oar market -will contlnuo to B be bo over-stocked that tho prices prevalltog' there will be extremely fl low. The law of supply and demand Wk prevails In the motor car field as elsewhere. As motor car practice approaches ap-proaches more nearly to a standardized standard-ized basis and body styles bocome more stablo (if they ever do), owners own-ers may bo expected to retain their cars longer, the used car market may become more lightly stocked, and the rate of depreciation of cars, by age, may be somewhat reduced. STORAGE BATTERY QUERY. H. Ij. Inquires as to the difference between the common type of storage battery and the Edison storage battery? bat-tery? Answer: The former consists of two sets of lead plates or grids filled respectively with spongy lead and a lead oxide, immersed in dilute sulphuric sul-phuric acid, while the latter consists 'of two sets of plates or grids of nickel plated stool, one sot carrying nickel hydrate and the other sot Iron oxide, as active material and the whole being immersed in a solution of potash. Tho voltage of the Edison Edi-son cell Is lower than that of the lead cell, but the formor is capable of -withstanding harder service for long periods than la the lattor. This column is devoted to the interests of the automobile owner and B operator. Both pleasure and commercial cars will be considered from every B aspect. The main articles will cover all phases of the running and care H of motor vehicles, what to do and what not to do. Questions of general H Interest to motorists xoill be answered, space permitting. Address Albert L, H Olough, care this office. |