Bike Hub Width

The freewheel threading on these older hubs is generally interchangeable except for some very old french units.

Bike hub width. Subtract this number from the rim half width. The boost hub is an alternative standard width for mtb front and rear hubs. Mountain bikes have adopted a 135 mm rear hub width which allows clearance to mount a brake disc on the hub or to decrease the wheel dish for a more durable wheel. Introduced by manufacturers trek and sram the boost standard widens the rear axle by 6mm and the front axle by 10mm.

The spacing of a hub is measured from the outside faces of the cone locknuts where they come into contact with the frame s forkends most cartridge bearing type hubs don t have locknuts so the spacing is measured from the equivalent shoulder surface of the axle ends the spacing dimension is commonly referred to as the o l d over lock nut distance. Buying a new or used bicycle. Add the rim offset to centre to right width and. Typical road bike rear hub is 130 mm wide while mtb freehub is a little wider.

If you go from a 5 speed freewheel to a 6 or 7 speed freewheel you will usually need to add some spacers to the right end of the axle between the cone and the locknut once you have done this you ll also need to re dish the wheel to bring the rim back to the centerline. Buy and sell bikes parts and accessories. The amount by which the rim reduces your wheel s dish. This creates 148 x 12mm rear hubs and 110 x 15mm front hubs.

To do this remove the rear wheel and use a pair of calipers or a ruler to measure the distance between the inner surfaces of the dropouts. It is usually a couple of millimeters. If you are unsure of your frame spacing or have an older bicycle measure the hub width to ensure a proper fit. Fat bike fork with 135mm skewer typical rear hub standard and front hub spacing.

Newer standard of mtb rear hubs for extreme riding condition is made even wider with matching frames with wide dropouts so the wheels are even stronger. The aim of the new standard was to keep up with the increasing demand for bigger 29 wheels. Thus rim offset w 2 l. Freeride and downhill are available with both 142 and 150 mm spacing.

The result is the rim s spoke hole lateral offset or just rim offset i e. 135 mm allowing more lateral strength. Thru axle bikes with a hub width of 148 mm do not work with the kickr snap. 135qr was originally a rear hub standard until fat bikes came along and flipped everything upside down and sideways.

In this pwb tutorial we cover how to determine the effective rim diameter erd as well as how to measure a bicycle hub for the sake determining proper spoke length using our spoke calculator.