Mountain Bike Thru Axle Sizes

142 x 12 thru axles are all the rage now.

Mountain bike thru axle sizes. This is done via visual reference. Thru axles are commonly 12mm 15mm and 20mm in diameter. 15x100mm 15x110mm boost and 20x110mm the first number refers to the axle diameter while the second refers to the dropout width of the bike. Ensure your rear hub is the correct size to fit your frame.

Determine if your frame fork uses a thru axle ta or skewer qr. Traditionally frames and forks had slotted dropouts. Thru axles are also inserted through a hollow hub axle but they re bigger rear ones are 12mm in. 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.

You can see more details about these measurements below. Front mtb thru axles currently use three standards. The diameter of the thru axle there are two common sizes. Spacing on these is 142mm wide with an axle diameter of 12mm.

Plus there are additional lengths for split pivot bikes and trek boost abp. 15 x 100mm 127 length 1 5. 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. 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. Rear thru axle from my evil following uses a 12 x 142mm m12 x 1 5mm thread pitch shimano e thru standard. Thru axle hub ta skewer hub qr step 2. Using a tape measure measure inside width of frame fork where hub contacts frame fork.

They essentially operate the same as front thru axles on the rear of the bike. Most thru axles are described by four measurements and you might see them described something like this. Boost being newer isn t as much as a clusterfuck. 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.

A guide to mountain bike axle standards 1. Thru axles make the bike stiffer which reduces lateral flex and results in better tracking especially through corners and at speed. Early cyclocross bikes borrowed the 15mm front thru axle diameter but as disc brakes became more common on drop bar bikes they all standardized to 12mm. 180mm length 20mm thread length.