TRADITIONAL THREAD-ON FREEWHEELS - SHELDON BROWN-BICYCLE.
MX650 FreeWheel Sprocket Electric Pocketbikes Well you could buy a h25 chain that may help or you could buy a stronger sprocket they are not hard ro replace. Freewheels screw onto the hub without any tools, then, as you ride the bike, your pedaling effort tightens them down. Learn how to replace bike spokes from Silk Road Cycles' Brendon Nicholas in this Howcast bicycle repair and maintenance video.