Or…a shaft-driven bicycle is a bicycle that uses a drive shaft instead of a chain to transmit power from the pedals to the wheel. Shaft drives were introduced over a century ago, but were surpased by chain-driven bicycles due to the gear ranges possible with sprockets and derailleurs. Recently, due to advancements in internal gear technology, this type of bike is now being introduced to the consumer market. The drive shaft is often mated to a hub gear which is an internal gear system housed inside the rear hub. Today, there are four significant manufacturers of internal hubs suitable for use with shaft drive systems, including Shimano, Nexus, SRAM and Sturmey-Archer.