Road wheel axles and quick releases

Thru-axle, quick-release skewer or adaptor

This category brings together three types of part that are easy to confuse: the quick-release skewers, the thru-axles and the hub end caps and adaptors. They serve different purposes and cannot replace one another.

The quick-release skewer

• A hollow 5 mm skewer that passes through the hub and is tightened by a cam lever.
• Road bike hub spacing: 100 mm at the front, 130 mm at the rear. “9 mm” in product titles refers to the hub axle diameter, not the skewer diameter.
• It is fitted to almost all bikes with rim brakes.

The thru-axle

• A solid 12 mm axle that screws into the frame dropout: stiffer, and essential for keeping the disc brake caliper aligned.
• 12x100 mm at the front and 12x142 mm at the rear on almost all road bikes with disc brakes.
• The thread pitch and the overall length vary from frame to frame: two axles labelled 12x142 may not be interchangeable. Check the original part number or measure them.
• The versions Plug In and Stealth are operated with an Allen key and give the bike a cleaner look; lever versions can be removed without tools.

Hub end caps and adaptors

• These are the end caps for the hub, allowing you to switch between standards — from quick-release to thru-axle, or from 15 to 12 mm at the front.
• They are specific to the hub rather than the frame: a Mavic QRM adaptor will not fit a DT Swiss hub.
• Mavic offers its ID360 adaptors in Centre Lock and 6-bolt : the disc brake setup determines what fits, not spacing alone.

The three measurements to take

The frame or fork spacing, axle diameter and, for a thru-axle, its overall length and thread pitch. Taking these measurements takes two minutes and prevents almost all returns in this category.

To find out more: How to choose wheel skewers

See also: Road bike hubs · Road disc brake wheels · Road disc brake adaptors