Abstract: A power transfer apparatus for imparting drive motion to followers. The power transfer apparatus mechanically and rotatably communicates with a driven wheel of a vehicle and transfers rotary power to the non-driven wheel of a vehicle. The present invention teaches a power distribution apparatus for mountain bicycles that mechanically and rotatably communicate with a pedal driven wheel and that transfers rotary power to the non-driven wheel to improve the forward propulsion of the mountain bicycle under rough terrain riding conditions. The power transfer apparatus includes a first caliper assembly having a driver idler and an auxiliary free wheeling idler for engaging a pedal driven wheel of a bicycle, a cable drive system coupled to the driver idler transfers drive motion from the driven wheel to a second caliper assembly having a receiver idler that engages the drive motion to the non-driven wheel.