Kettenfänger

Kettenfänger, in English often called a chain catcher, is a device mounted near the bicycle chainring to catch a chain that would otherwise drop into the gap between the chainring, crank, frame, or bottom bracket. Its primary purpose is to prevent the chain from slipping into hard-to-reach areas, reducing the risk of damage to components and injury to the rider.

Design and placement

A Kettenfänger typically consists of a small plate or finger that extends below the lowest point of the chainring. It can be made from metal or reinforced plastic and is attached to the crank, chainring, or frame using screws or a clamp. Some designs are integrated into the crank or frame, while others are aftermarket parts installed near the chainring. The device must be positioned so it intercepts a dropping chain without interfering with pedal rotation or shifting.

Usage and compatibility

Chain catchers are commonly found on road, cyclocross, and mountain bikes, especially on setups with multiple front chainrings or less robust front derailleurs. They are particularly useful for riders who experience occasional chain drops or for frames with less clearance around the chainring. Modern 1x drivetrains see less need for chain catchers, but they are still used on some bikes for added security or during rough riding.

Materials, maintenance, and limitations

Common materials include stainless steel, aluminum, and durable plastics. Maintenance involves checking alignment and ensuring the catcher does not rub against the chain, crank, or derailleur. Potential drawbacks include added weight, possible noise, and the need for occasional readjustment to maintain proper clearance.

See also

Chain guide; chain stay protector; derailleur.