mudguard

A mudguard, commonly known as a fender in North American English, is a protective device mounted over the wheel well of a vehicle to intercept water, mud, and debris thrown by the rotating tire. Mudguards reduce spray that can soil riders' clothing and the vehicle's components, and they also help protect bystanders and neighboring vehicles from road spray.

On bicycles, mudguards are typically made of steel, aluminum, or plastic and are attached to the fork crown, the seat stay, or the frame with stays or bosses. They come in full-length designs that extend from near the top of the wheel to the chainstay, and half-length designs that cover only the upper part of the wheel. Clip-on and integrated varieties exist.

In motorcycles and cars, mudguards serve similar splash protection; car mudguards are more commonly called fenders, while motorcycles use front and rear fenders. Materials vary from metal to plastic, and some designs include integrated fairings or aerodynamic shaping.

Terminology varies by region: mudguard is common in British English; fender is used in American English. In some contexts, “guard” is used in the United Kingdom, while “mudflaps” refer to a different device located behind the wheel on larger vehicles.

History and regulation: mudguards appeared in the late 19th century on bicycles and became widespread on automobiles in the early 20th century. In many jurisdictions, mudguards are required or recommended for certain vehicles to reduce debris thrown onto other road users, especially in wet conditions. Maintenance involves periodic cleaning, checking alignment, and replacing cracked or bent guards to ensure effective protection.