Mtb Axle Standards

At first 135mm was the most common rear axle spacing with 150mm used for dh.

Mtb axle standards. 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 think there would be three as there are three distinct rear hub types. There are three common types of freehubs drivers. 15x100mm 15x110mm boost and 20x110mm the first number refers to the axle diameter while the second refers to the dropout width 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. A rockshox maxle a threaded 15mm thru axle with cam lever. I obviously wasted a lot of time researching this crap there are basically three different rear axle types seen as the current standard for mtb rear thru axles. Driver vs free hub hg mtb vs hg 11spd road vs xd.

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. 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. 9mm x 135 mm 12 x 142 mm. Front 15mm and 20mm bolt thru axles bolt thru axles are wider stronger and stiffer than qr systems and have been standard on most high end performance mountain bikes for about the last ten years.

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. There s also a 20mm boost version out there which is also 20 x 110mm but has different brake spacing it s pretty limited at the moment so we ll ignore for now. But 142mm and 157mm soon superseded these standards with the extra 7mm allowing a stiffer interface with the frame. There are two common types of hg free hubs mtb and 11spd road.

The diameter of the thru axle. The 20mm is generally used for dh enduro and the 15mm for just about everything else. Most thru axles are described by four measurements and you might see them described something like this. Hg stands for hyperglide.

Shimano s 11spd road cassettes are just a little bit wider than their mountain bike cassettes.