The freewheel allows for a quick response when pedaling.

In most cases, the freewheel is installed on the right crank, using a sprocket on the rear hub. The size of freewheel most frequently used is 18 teeth.

Key points:

· Engagement points and pawls: the more, the better, faster response. Most popular/recommended freewheels are those with 108 or 135 engagement points, with 9 pawls.

· Number of teeth: normally, 12 teeth rear sprockets are used for 20” bikes, 14t for 24” bikes and 15t for 26” bikes. Kid bikes usually have a 13t or 14t sprocket.

· Threaded vs. Splined: sprockets can be threaded (standard 1.37” x 24tpi thread) or splined (Echo splines, Shimano HG cassette, etc.).