There are a lot of different types of thru axles on the market. Here is a quick guide to explain the specification differences.
Rock Shox: Rock Shox uses a 15mm axle on most of their forks but downhill forks use a larger 20mm thru axle. They use a standard length with a 1.5 pitch.
Fox: Fox uses a 15mm axle on most of their forks but, the treads are 14mm in diameter. They use a standard length with a 1.5 pitch.
Road: In general, road bikes that are equipped with disc brakes use 12x100mm spacing. This doesn't mean you'll need a 100mm long thru axle since the width of the fork varies between each bike. And there's very little consistency between brands so you need to check all the dimensions carefully. You'll probably need a thru axle that is 118mm or longer.
Mountain bike: Most cross country, trail and most enduro bikes come with 12x148 aka Boost spacing. Some bikes use the 12x157mm standard. Since frame width affects the length of the thru axle and widely adopted standard thread, you'll need to check the dimensions carefully. You'll probably need a thru axle that's 170mm or longer.
Road: Road frames, in general use 12x142mm spacing, but this doesn't mean you'll need a 142mm long thru axle since the width of the frame makes a difference for the length of the thru axle. You'll probably need a thru axle that’s 160mm or longer.
The coarseness of threads is called pitch and to find the pitch, you need to count the number of threads over a 10mm section.
12mm REAR THRU-AXLES - There are 3 primary specs for M12 axles – Fine, Medium and Coarse
Please log in!LOGIN