Front freewheel
From Wikipedia, the free encyclopedia
The Shimano front freewheel design was an innovative bicycle drivetrain design of the 1970s. To improve the normal bicycle with a freewheel between the rear sprocket cluster and wheel hub, Shimano inserted a freewheel between the pedal cranks and the front chainrings that enabled the rider to shift gears while coasting. For safety reasons, however, the normal rear freewheel also had to be retained to stop the chain if clothing got tangled in it, which would otherwise lead to injuries of the leg by the drivetrain, crashing of the bicycle, or both. In addition, the marketing followed Shimano's then-current path of beginning with lower-cost implementations of the system using low tech and usually heavier materials. For one or both of these reasons, the resulting system was substantially heavier than the standard freewheel and, in any event , did not penetrate the market noticeably, although some Panasonic bicycles were briefly equipped with it.
