The crank arm shortener reduces the diameter of the pedal stroke for the crank arm on which it is installed.  Crank arm shorteners can be installed on both sides for riders of differing leg lengths or those with limited mobility in one or both legs.  Can be installed on most cranksets for both traditional and recumbent bikes and trikes.

The new forged part looks nicer than the previous version but is also more robust and can even be properly aligned on offset crank arms.