Axles

Fork Axle Buying Guide

The fork axle clamps your front wheel into the fork lowers. Getting the right one is a simple compatibility exercise — there are only a few standards, and they're not interchangeable.

Thru-Axle Standards

Modern MTB forks use one of three thru-axle standards: 15x100mm (non-Boost, legacy), 15x110mm (Boost, current standard for most trail/enduro/XC forks), and 20x110mm (Boost, DH forks and some older enduro forks). The first number is the axle diameter, the second is the hub spacing (distance between the fork dropouts). Boost spacing (110mm) is now standard on everything except some XC race forks and older models.

Thread Pitch and Length

Beyond the diameter and spacing, you need to match the thread pitch. RockShox Maxle uses M15x1.5 threads. Fox Kabolt uses the same thread but a different lever mechanism. Thread length also varies — some forks have longer threaded sections than others. The safest approach is to match the replacement axle to your exact fork model and year.

OEM vs Aftermarket

RockShox Maxle Stealth and Fox Kabolt are the OEM options — reliable and straightforward. Aftermarket axles from Robert Axle Project, DT Swiss and Wolf Tooth offer lighter weight (titanium or aluminium), tool-free operation, or different lever designs. Robert Axle Project also makes rack and trailer-compatible axles with secondary attachment points. For most riders, the OEM axle is fine. If you've lost yours or want a lighter one, the aftermarket options are worth a look.

Quick Release Forks

Some budget and older forks still use 9mm quick-release axles. These are lighter and easier to use but significantly less stiff than thru-axles. If your fork uses QR and you're upgrading, you'll need a new fork — there's no conversion kit from QR to thru-axle.