How do I know what size axle I need for my bike?

Measure the straight length of your axle shaft. Do not include the axle head or tapered spacer, if there is one. Axle length is not the same as hub length. A bike with a 12×142 hub standard will have a significantly longer axle since it will have to go through the frame on both sides of the 142mm wide hub.

What size is a bicycle axle?

At the front, road bike thru-axles are now pretty much standardised at 100mm long by 12mm wide (although some early thru-axle road bikes had 15mm diameter thru-axles). Rear thru-axles usually measure 142mm long and have a 12mm diameter, but you used to be able to find a few bikes with 135mm thru-axles.

What is a 12mm thru-axle?

From this specification we know 142mm is the hub width (or frame spacing) and 12mm is the diameter of the axle. Total Thru Axle length from the seat to the end of the threads.

What is 15mm thru-axle?

15mm thru axle uses a different connection on the fork where the axle of the wheel allows a 15mm bolt to go through it. Same concept for a 20mm thru axle. Some wheel manufacturers have adapters that allow you to use the same wheel with the different fork hub standards by swapping out the axle ends.

Can I convert quick release to thru axle?

You can use through bolts (which can be quick release) in QR dropouts. These require specific hubs that allow for a 9mm front through bolt and a 10mm rear through bolt. On most Shimano hubs (and some similar Formula type hubs) you can replace QR axles with solid axles and use axle nuts on each end.

Is my bike through axle?

Your bike has a thru axle if the “drop out” is a hole, rather than a U-shaped dropout. This provides added security because even if the lever on the end of the thru axle flips open, it is still threaded into the frame, holding your wheel on. If you have a 12mm threaded piece, then you have a thru axle.

What are the different types of bike axles?

There are two types of Axles; Quick Release and Thru-axles (which come as standard or boost).

What is thru axle frame?

A thru-axle (TA) is a wheel attachment system that secures a wheel on a hub between a pair of dropouts on a bicycle frame or fork. The thru-axle threads directly through the fork/frame holes and into the wheel hub, which makes the wheel secure from detaching.

Do I need thru axle adapter?

You’ll need an adaptor in order to fit a thru axle bike to a wheel-on trainer. You usually have to buy the adaptor separately. Most direct drive trainers now come with whatever’s necessary to use it with a thru axle bike.