CRANK DROP AND CRANK THROW.
There seems to be some disposition to substitute “what is the drop” for the recent question “what does it weigh?” It is not certain that most people understand that “drop” means anything more than a lowering of the crank-hanger and a relatively slight lowering of centre of gravity; it does in fact mean more. The drop is the lowering of the crank axle below a line drawn between the two wheel axles. This line is fourteen inches from the ground. If one will stop to consider that from this must be taken, in use, the drop of axle, the crank throw, the dip of pedal below its own pivot, and the further dip of the toe-clip which no strictly up-to-date scorcher can omit without endangering his caste, he will see that to combine (as some wish and propose to do) a 3-inch drop with a 7-inch crank is to invite disaster. Not more than a single inch of clearance from the ground remains. This inch is as good as a yard while it lasts, but can anybody carry it in his pocket and thus make sure of always having it? There is the inclination on curves, and ruts and stones may be encountered, even if riding is confined strictly to the asphalt.
The length of crank throw is periodically discussed, and there is a disposition to jump to the conclusion that excessively high gear ratios may be made easy by increasing throw to 7 or 8 or even to 8½ inches. We do not think it worth while to go into this discussion at present, but will state five propositions: 1. The customary crank throw, like the size of wheel and some other factors, has not been obtained arbitrarily, but as a compromise between opposing considerations. 2. The labor of high gears is not thus easily disposed of, because the increased leverage involves a longer circle of travel, a change in the position of seat relative to pedal, and different angles in the muscular action. 3. The throw is closely related to the length of argument set up by some that proper crank upper and lower leg and the length of foot is fanciful rather than sound. 4. The question of crank throw, like that of vertical or forward thrust, must be counted among individual matters and is not to be disposed of by the dictum of any one person set up against the rest of mankind. 5. A long crank is, however, positively wrong for use by women, because it increases the high rise of the knee which, for them, is so ungraceful and is both mechanically and hygienically wrong.
“CLOCK” DIAGRAM—ORDINARY PEDAL.