Mountain Bike Thru Axle Sizes

The hub axle which was 9mm in diameter.

Mountain bike thru axle sizes.

Determine if your frame fork uses a thru axle ta or skewer qr. 15x100mm 15x110mm boost and 20x110mm the first number refers to the axle diameter while the second refers to the dropout width of the bike. 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. 180mm length 20mm thread length.

Boost being newer isn t as much as a clusterfuck. Thru axles are also inserted through a hollow hub axle but they re bigger rear ones are 12mm in. The diameter of the thru axle there are two common sizes. Using a tape measure measure inside width of frame fork where hub contacts frame fork.

15 x 100mm 127 length 1 5. Thru axle hub ta skewer hub qr step 2. Rear thru axle from my evil following uses a 12 x 142mm m12 x 1 5mm thread pitch shimano e thru standard. Thru axles make the bike stiffer which reduces lateral flex and results in better tracking especially through corners and at speed.

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. 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. 142 x 12 thru axles are all the rage now. They essentially operate the same as front thru axles on the rear of the bike.

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. Ensure your rear hub is the correct size to fit your frame. You can see more details about these measurements below. 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.

Traditionally frames and forks had slotted dropouts. 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. This is done via visual reference. Front mtb thru axles currently use three standards.

Skewers are almost always 5mm in diameter. Most thru axles are described by four measurements and you might see them described something like this. A guide to mountain bike axle standards 1. Spacing on these is 142mm wide with an axle diameter of 12mm.