TireThe rubber tire that meets the road, fitted on the rim.
RimThe metal or carbon hoop the tire sits on. The spokes pull it into a true circle.
SpokesThin wire spokes that hold the rim to the hub, pulled tight.
NipplesThe small nuts that hold each spoke's end to the rim. Turning them tightens or loosens the spoke.
ValveWhere the tire is pumped up. It is on the inner tube, through a hole in the rim. Presta valves are narrow. Schrader valves are the car kind.
HubThe center of the wheel. A shell round the axle, turning on bearings.
FlangesThe two rings on the hub, one each side. The spokes hook through their holes.
AxleThe rod through the hub that the wheel turns on. It is held in the frame.
CassetteA stack of toothed sprockets on the rear hub. The chain drives them. Changing gear moves the chain to a bigger or smaller one.
Quick-release skewerA rod through the hollow axle. It has a lever at one end and a nut at the other. Flipping the lever clamps the wheel in the frame, or frees it without tools.
How this list was compiled: Read 2026-09-27. (1) Wikipedia, Bicycle wheel, https://en.wikipedia.org/wiki/Bicycle_wheel : a hub of metal, wire tension spokes, a metal or carbon fibre rim; the hub: axle, bearings and hub shell with two flanges the spokes attach to; nipples; rim tape and inner tubes; the valve stem; the quick-release skewer through a hollow axle, for fitting the wheel without tools; a cassette of sprockets on the freehub; the freewheel. (2) US Consumer Product Safety Commission, 16 CFR 1512.10 to 1512.12, https://www.law.cornell.edu/cfr/text/16/1512.12 : requirements for tires, spokes, rims and wheel hubs, locking devices on threaded axles and lever-operated quick-release devices. Sheldon Brown's Bicycle Glossary, https://www.sheldonbrown.com/glossary.html : the nipple as the nut that secures a spoke's end to the rim; the hub flange; the cassette; Presta and Schrader valves. Licence: own work
The drawing: Drawn for this site by script, 2026-09-27. Own work, nothing traced. Licence: own work
How it works
These are the parts of a bike wheel, a rear wheel, drawn face-on from the chain side and then with its hub seen from above so the axle, flanges and cassette show.
Read the full guide
Face-on
The tire sits on the rim, and the valve pokes through the rim to pump it up. Spokes run from the hub out to the rim, each held at the rim end by a nipple.
The hub
The hub turns on the axle, and the spokes hook through the flanges on each side of it. The cassette's sprockets sit on the rear hub for the chain. The quick-release skewer runs through the hollow axle and clamps the wheel in the frame.
To take a wheel off with a quick release, open the lever rather than unscrewing the nut.
Questions and answers
What are the main parts of a bicycle wheel?
The hub in the middle, the spokes, and the rim round the outside, with the tire on the rim. The hub turns on its axle.
What is a spoke nipple?
The small nut that holds a spoke's end to the rim. Turning it tightens or loosens that spoke, which is how a wheel is trued.
What is the difference between Presta and Schrader valves?
A Presta valve is narrow and used on most high-performance bikes. A Schrader valve is the wider, car-style valve found on children's and everyday bikes.