Hook rim

A hooked rim is a special type of bicycle rim that has a hook shape to hold the tire securely on the rim. Hooked rims are particularly common on road bikes and older bikes.

How does a hook rim work?

The hook shape of the rim creates a depression in the rim where the bead of the tire is clamped. This prevents the tire from coming off the rim, especially at high speeds and tight corners.

Hook rims are typically made from aluminum or steel and can come in a variety of sizes and widths. The rims can also have different heights to provide better aerodynamics or strength.

A special type of hook rims are the so-called "bevel hook rims" which became popular in the 1950s. These rims have a special bevel hook shape which provides greater lateral stiffness and improves braking in wet conditions.

Problems with hook rims

While hooked rims were widely used in the past, they are less commonly used today due to safety concerns . If the rim is damaged or deteriorated, the tire can slip off the rim and cause a serious accident. Modern rims typically have a "hookless" design, where the tire is attached to the rim by other methods such as a tubeless system or a clamp.