BIKE WISDOM.

Hawke's Bay Tribune, Volume III, Issue 189, 26 July 1913, Page 2 (Supplement)

BIKE WISDOM.

p — POINTS YOU MAY NOT KNOW ABOUT YOUR STEED OF STEEL.

How many cyclists—apart from the thorough-paced enthusiasts—among those whose wheels flit nioselessly over tho roads of this country ever stop to think what a marvellous production their machines really are ? Does it not seem extraordinary that a man, whose unaided efforts would not permit him to walk at more than three miles an hour, or to cover more than twenty-five miles in the day, should be enabled, merely by taking along with him a thing weighing some thirty pounds, or even more, to travel at anything from three to five times his walking pace, and cover a correspondingly greater distance? THE RAW MATERIALS. The average cyclist will be rather surprised to learn that even a single-gear-ed cycle has no fewer than 1,500 separate pieces; and, if a variable-speed hub is included in the equipment, this total, large as it is, will be increased by another 100 or 150 parts . Again, take the materials of which a cyclo is made. Steel, rubber, leather, celluloid, aluminium, will occur readily to the mind; -but these are only the beginning. Cotton, for instance. Did you know that from five to seven thousand feet of cotton are hidden away in the fabric of your tyres ? Other substances, all necessary, but not always thought of by the possessor of the machine, are cement, cardboard, chalk, zinc, solder, copper, brass, Bal-tic-oil, gold-size, vulcanised fibre, and, in the case of racing machines, horn and bristles for the handlegrips and the chain-brushes in the gear-case respectively.

Tho majority of cycle fittings of the better class are made of steel forgings. This means that from 60 per cent, to 80 per cent, of the metal put into the forging has to be wasted in cutting away to make the finished fitting ready for the assembler to build into the machine. A forging for a rear hub, for example, weighs 230 z. The finished hub weighs but soz. 4dr. IN THE RIGHT M AY. A forging for a box crown weighs 16 oz. ; for the finished crown the weight lias been pared down to 4oz. 9dr. A bicycle is a marvellous example of strength rightly applied. A cycle frame, even of the best quality, can be bent almost double across the knee of a fairly powerful man when twisted sideways; but in actual practice it is never required to withstand strains in this direction. Directly downward—tho way in which the rider’s weight acts —its strength is enormous. A cycle was recently loaded with qjeven men, making a total weight cf nearly three-quarters of a ton, without showing the least ill-effects. It must be borne in mind that the wheels, fra-gile-looking as they are, had also to withstand this strain.

The spokes of the wheels are another example of this specialised strength. You may bend a spoke sideways without any difficulty—a pair of strong wrists might even break it with a few twists —but that is not the Way In which it is required to spend its useful life; try pulling it Christmas-cracker style.

It would probably take more tons to achieve this than you weigh stones. Or, again, take the chain. This, if cf average length, will contain some <561 pieces. It would fake an end-on pull of terrific strength to cause it to part company, in the case of one of first-class make. ACCURACY TO A DEGREE. Perhaps the most beautiful piece of work in a cycle is the three-speed hub, which is now an accepted fitting on all but tho cheaper class -of machine. As ono prominent firm put it in their descriptive list, “so much has to be done in the small space allowed in the back hub of a bicycle that a variation of onethousandth part of an inch would be sure to cause trouble, and would be considered a defect in construction..” . 9 ven degree of accuracy is insufficient to meet the demands made on tho steel balls used in the bearings of a good machine. In these tiny spheres an error in either diameter < r circularity of three then-thousandths of an inch would be thought sufficient to cause rejection.