US Patent 7850577 Free wheel clutch mechanism for bicycle drive train

A clutch mechanism may be positioned in engagement with a slave sprocket of a drive train and a hub of a flywheel to create a frictional engagement between the sprocket and the hub, and to establish a break-free force threshold. When the drive train is actuated in the forward direction, the slave sprocket and the hub may move together, and when the drive train is actuated in the rearward direction under the influence of a force greater than the break-free force threshold, the clutch mechanism may slip between the slave sprocket and the hub, allowing the slave sprocket and the flywheel to move independently of one another. The clutch mechanism may also include a spring tensioner whereby the break-free force may be adjusted.