Bicycle chain - online puzzles

A bicycle chain is a roller chain that transfers power from the pedals to the drive-wheel of a bicycle, thus propelling it. Most bicycle chains are made from plain carbon or alloy steel, but some are nickel-plated to prevent rust, or simply for aesthetics.

History

Obsolete chain designs previously used on bicycles included the block chain, the skip-link chain, and the Simpson lever chain. The first chains were of a simple, bushing-less design. These had inherent reliability problems and a bit more friction (and mechanical efficiency losses) than modern chains. With these limitations in mind, the Nevoigt brothers, of the German Diamant Bicycle Company, designed the roller chain in 1898, which uses bushings, and it is the prevalent chain today. Whether it be single rear cog (for example coaster-brake single-speed or with an internal-gears hub), fixed-gear (such as track bikes and modern urban "fixies") or multi-speeds with derailleurs, all modern chains in use today are of the "roller chain" design. Although it is still possible to order lower cost "bushing-less" chains from China today, with generally lower manufacturing costs across the board, bushing-less chains are generally considered undesirable and not prevalent.

The first solid bush-roller patent was filed by the Renold Chain company in 1880.

Early examples of chain-driven bicycles include the 1869 Guillemot and Meyer, the 1879 Lawson, the 1884 McCammon, the 1884 Starley Rover, and the 1895 Diamant.Before the safety bicycle, bicycles did not have chains and the pedals were typically attached directly to the drive-wheel, thus limiting top speed by the diameter of the wheel and resulting in designs with front wheels as large as possible.