Mountain Bike Thru Axle Sizes

When mountain bikes first went to thru axles the standard was 12 142 which was the same effective width as the quick release hubs they replaced.

Mountain bike thru axle sizes.

Rear thru axle from my evil following uses a 12 x 142mm m12 x 1 5mm thread pitch shimano e thru standard. Plus there are additional lengths for split pivot bikes and trek boost abp. Using a tape measure measure inside width of frame fork where hub contacts frame fork. Traditionally frames and forks had slotted dropouts.

You can see more details about these measurements below. Spacing on these is 142mm wide with an axle diameter of 12mm. Most thru axles are described by four measurements and you might see them described something like this. 180mm length 20mm thread length.

The hub axle which was 9mm in diameter. Thru axle hub ta skewer hub qr step 2. They essentially operate the same as front thru axles on the rear of the bike. Boost gives a 148 x 12mm spacing which allows for the hub flanges to be further apart which gives a potentially stronger and stiffer rear wheel.

Thru axles are commonly 12mm 15mm and 20mm in diameter. Front mtb thru axles currently use three standards. 15x100mm 15x110mm boost and 20x110mm the first number refers to the axle diameter while the second refers to the dropout width of the bike. Boost being newer isn t as much as a clusterfuck.

This is done via visual reference. In this example 15mm is the diameter 100mm is the o l d 127mm is the overall length and 1 5mm is the thread pitch. Cysky bike axle quick release skewer front rear bicycle axle wheel hub fit for road bike mountain bike mtb bmx 1 pair 3 9 out of 5 stars 325 11 99 11. The standard mtb rear axle dimensions are 135x5mm for a qr rear hub but jump and gravity bikes may use wider and thick axles for extra strength and stiffness with the available sizes being 135 10 142 12 150 12 157 12 and 165 12.

Skewers are almost always 5mm in diameter. Old quick release hubs and 142 x 12mm thru axle hubs have the same widths between the hub flanges so there is no change in terms of hub flange positioning and wheel strength and stiffness. Ensure your rear hub is the correct size to fit your frame. Thru axles are also inserted through a hollow hub axle but they re bigger rear ones are 12mm in.

A guide to mountain bike axle standards 1. The diameter of the thru axle there are two common sizes. Thru axles make the bike stiffer which reduces lateral flex and results in better tracking especially through corners and at speed. 15 x 100mm 127 length 1 5.