Spokes are steel or stainless steel and can be replaced if broken. Hubs and rims can be aluminum or steel but steel wheels are becoming rare in most countries. Aluminum rims are lighter and give much better braking in wet conditions. Typically they are anodized except for the braking surfaces. With disc brakes the whole rim can be anodized usually in black or silver. Wheels may also be cast or molded in one piece from aluminum alloy plastic and carbon fiber for various specialty bikes plastic for example was once favored for BMX bikes.

The wheel axle fits into dropouts in the frame and forks. A pair of wheels may be called a wheelset especially in the context of ready-built off the shelf performance-oriented wheels.

Tires vary enormously. Skinny road-racing tires may be completely smooth or slick. On the opposite extreme off-road tires are wider and thicker and usually have a deep tread for gripping in muddy conditions.


Some components which are often optional accessories on sports bicycles are standard features on utility bicycles to enhance their usefulness and comfort. Mudguards or fenders protect the cyclist and moving parts from spray when riding through wet areas and chainguards protect clothes from oil on the chain. Kick stands keep a bicycle upright when parked. Front-mounted baskets for carrying goods are often used. Luggage carriers and panniers can be used to carry equipment or cargo. Parents sometimes add rear-mounted child seats andor an auxiliary saddle fitted to the crossbar to transport children.