Freewheeling

Freewheeling is a mechanism that allows a vehicle's driven wheels to rotate independently of the engine or drivetrain. This is most commonly associated with bicycles, where the freewheel, typically located in the rear hub, enables the rider to stop pedaling while the bicycle continues to move forward. When the pedals are not being driven, the freewheel mechanism disengages the rear cogs from the hub, allowing them to spin freely.

In automobiles, the term "freewheeling" can refer to a transmission system that allows the driven wheels to rotate faster than the engine. This was more common in older vehicles and could be achieved through various mechanical means, often involving a special clutch. When engaged, the engine would drive the wheels, but when disengaged, the wheels could spin independently. This was sometimes used for coasting downhill to save fuel or reduce engine wear.

Modern cars generally do not employ a true freewheeling system in the same way as bicycles or older automobiles. Instead, engine braking is more prevalent, where the engine's internal friction helps to slow the vehicle when the accelerator is released. However, some specialized vehicles, like certain off-road or commercial vehicles, might incorporate mechanisms that allow for a degree of independent wheel rotation for specific operational advantages, though the term "freewheeling" itself is less frequently applied. The primary function across all applications is to decouple the driven wheels from the power source under certain conditions.