BMX Parts Compatibility Guide

Most BMX parts are built to a handful of standards, but there are enough of them that mixing parts can go wrong fast. This guide covers the checks BMX Creator runs for you, and the ones you still need to do yourself. Treat it as a starting point, and check each shop listing and ask a bike mechanic if you are unsure.

Crank spindle, bottom bracket and sprocket

Cranks come with a spindle in common sizes of 19mm, 22mm and 24mm, and many use a 48 spline spindle. The bottom bracket has to be made for the same spindle size, and the sprocket has to fit the crank’s spline or spindle standard. If the three do not agree, the crankset will not assemble.

Fork axle and hub axle

Front hubs and forks are made for axle sizes such as 10mm, 14mm or 3/8 inch. The hub axle and the fork dropouts have to match. The same goes for the rear hub and the frame’s rear dropouts.

Headset, frame and fork

Headsets come in integrated, mid (also called semi-integrated) and external cup styles, and most BMX steerers are 1-1/8 inch. Some forks use a tapered steerer and need a matching tapered headset. The frame’s head tube decides which headset style fits.

Seat and seat post

Pivotal seats need a pivotal post. Railed seats need a railed post or a rail clamp. Also check the post diameter against the inside of your frame’s seat tube.

Wheels, rims and tires

Rims, tires and hubs need to share a wheel size. A 20 inch BMX wheel uses a 20 inch rim and a 20 inch tire. Hub spoke counts also have to match the rim.

Chain and drivetrain

Chains come in different widths, and the chain, sprocket and rear driver or cog have to be the same width. Count on needing to size or shorten the chain for your frame.

Pedals

Pedals use either a 9/16 inch or a 1/2 inch thread, and the crank arms have to use the same thread. Check this in the product description.

Brakes

Brakes need brake mounts on the frame and fork if applicable, a matching lever, and a cable. If your frame has no mounts, ride brakeless or choose a different frame.

The honest disclaimer

BMX Creator is a fun tool. Its fit checks read the shops’ own descriptions and are not a guarantee, so some parts will not be compatible with each other. Please consult a bike mechanic before ordering anything. Questions or corrections are welcome at contact@campaignya.com.