Road Bike Axle Length

The bike industry is known for not creating or adhering to standards but it wasn t until i needed a rear axle i realized how bad it had gotten.

Road bike axle length. If you assume a wheel base of 1000 mm most modern road bikes have a wheel base close to that you can predict the change in head angle for a given fork swap on a typical road bike. The length of the axle not including the head. 4 mm longer axle shimano s optional extended axle adds 4mm to the distance between the crank and the foot position. The first crop of disc bikes used quick release with 100mm axle length at the front and either 130mm or 135mm at the rear.

Arcsin old length new length wheel base but you don t have to use the formula. So having determined the size and thread pitch of the thru axles i need i m struggling to find one which is the correct length. Digging through my bins of collected bike parts i pulled a not small selection of rear through axles in what was the correct length and spacing for a 12 x 142mm rear hub. You don t actually need nearly this much so for respacing hubs to wider spacing if you re not adding more than say 5 6 mm of spacers you don t need a new axle.

This allows riders with naturally wider hips to maintain correct leg and foot alignment on the pedals. Thanks for the feedback. Flat or conical total length. There are 4 main attributes to consider when determining the proper thru axle standard for your bike.

Don t assume that because your frame is boost 148 and uses e thru that it requires the e thru boost 148 axle as often it may not. If it s too much will then go to a custom fork from woundup bloody expensive but best option found so far to get the correct axle crown length. Having looked around the brand x range seem to come closest to what i need but the lengths available are just a tad too long theirs being 125mm and 166mm. Then along came thru axles borrowed from mountain bikes where they.

The front measured from the base of the bolt to the end of the threads needs to be 117mm and the rear 160mm. This gives 5 5 6 mm of axle protrusion on each side. Axle length typical quick release axles are 11 or 12 mm longer than the spacing of the hub locknuts. This size specific approach goes a long way to getting you set up with the correct stem length providing you ve chosen the right size frame another area where a bike fit comes in useful.

You can see more details about these measurements below. I m in the process waiting for the last of the parts of putting a disc on the road bike and will be going from 374 to 403mm using a mosso fork just to see the effect. The following table shows the numbers. 15 x 100mm 127 length 1 5.