Crank Bolt

There are a variety of methods used to attach the cranks to the bottom bracket spindle called the crankshaft pulley. Older cranks use a wedge-shaped pin, called a cotter, for attachment to the bottom bracket spindle. Newer cranks slide onto a square tapered spindle and use a bolt to secure the pulley to the crankshaft. It is recommended to replace this bolt while rebuilding and engine.