Читать книгу The Modern Bicycle and Its Accessories - Julius Wilcox - Страница 27

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“Sans Chaine sans Gêne,” literally “without Chains without Care,” or even “Chainless and Careless,” is the happy motto chosen by an English maker of chainless bicycles; some thirty American makers are offering or promising to offer a chainless bicycle of some kind this year, although whether they will all realize the declaration of the motto time alone will show.

There are a number of methods for transmitting power from the crank axle of a bicycle to the driven wheel—possible theoretically, but the number practically available is very small. The possession of the field by the chain is now contested, mainly by the bevel-gear or its equivalent; the chain has the field, but changes are sometimes so rapid that this fact alone will not effectually bar out a really better driving method. The elements of bevel-gear construction will readily be seen from the cuts following. The usual front sprocket has teeth, which mesh into a pinion on a shaft that carries power to the wheel through a pair of pinions at the rear.