Quick-Releases allow you to quickly remove a wheel from a frame without the need for tools.
They consist of a thin metal skewer which runs through the wheel’s hub axle, secured by a nut (called an acorn nut) on one side and a quick-release (QR) lever on the other, with two small springs in between. The wheel is secured by placing the axle in the frame or fork dropouts, loosely tightening the acorn nut and then clamping the QR lever closed – a cam mechanism then secures everything in place.
The skewer is typically installed so that it is on bike’s left side, with the acorn nut on the right (so that the rear QR lever doesn’t get in the way of moving drivetrain parts).
When choosing a quick-release the most important things to note are skewer diameter, skewer length, materials and cam type.
• Skewer diameter: For most standard road and MTB bikes, the wheel hubs will accommodate standard 5mm skewers. However the latest generation of ‘bolt-through’ MTB forks and frames utilizes larger-diameter axles for additional stiffness, with the ‘skewer’ being the actual axle. Typical sizes for front and rear bolt-thru axles are 10mm, 12mm, 15mm and 20mm depending on riding discipline and manufacturer’s standard, so ensure you purchase the correct size to fit your forks and hubs (in the case of the latter, adapters are available to enable hubs be used with regular 5mm QR, or different-sized bolt-through options).
Note: Bolt-through axles are typically supplied with your forks, rather than with your wheels, so you’ll find replacements under the ‘forks spares’ section of the website.
• Skewer length: Typical front wheel spacing for road and MTB bikes is 100mm from dropout to dropout, so you will need a 100mm skewer for your front wheel. There is a little more variance in rear wheel spacing, with 135mm being the standard on most road and standard MTB bikes, but 135mm or 142mm spacing standards (with bolt-through axles) are also used on some gravity bikes for more rear-end stiffness.
• Materials: Quick-releases will normally be made of a mixture of steel and aluminium depending on component parts – e.g. a stainless steel skewer for strength and machined aluminium QR lever to reduce weight. However look for steel threads (less resistant to stripping) and steel teeth on the acorn nut/cam washer as they will provide a more secure grip, outweighing the benefit of any miniscule weight saving from alloy parts.
• Cam type: There are two main types of QR skewer, enclosed cam and exposed cam. Invented in the 1930s by the legendary Tullio Campagnolo, the enclosed-cam type is the original version of the QR cam and features a steel cam enclosed by a solid metal body, ensuring it is well protected against the elements. The body moves back and forth when the lever is flipped, usually with teeth that lock against the dropout. The exposed cam is a later variant on the cam design, which instead of housing the cam in a metal body uses a split external cam that straddles the end of the skewer. A curved plastic washer is located between the cam and the toothed metal washer that presses against the dropout. Exposed-cam QR skewers are popular as they can generally be made a little lighter than the enclosed-cam type, but are regarded by some as being less robust.