mechanical-advice

 

Information & Advice

 

Bicycle Wheels

O.L.D.

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O.L.D.  (Over-Locknut Dimension)

This is the width of the hub measured from outside of locknut to outside of locknut. It is not to be confused with the axle length, as the axle extends into or beyond the frame dropouts.

The O.L.D. needs to match the available space in the frame between the fork or frame tips.

Hub Widths

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Rear Hub Widths & Dropout Spacing

Rear hubs vary in width (but most new ones are 130mm for road or 135mm for mountain). The hub width (over-locknut dimension) needs to match the space between the rear wheel dropouts in the frame in order for things to line up as they should.

120mm: 5 speed and "Ultra-6". An old hub size not used on new bikes.

126mm: 6 speed and some 7 speed.

130mm: 8 & 9 speed road.

135mm: Mountain 8 & 9 speed and some 7 speed.

Cassettes: Using 7 speed sprockets on 8 speed hubs.

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  • It is possible to fit 7 speed cassette sprockets to an 8 speed cassette body but it is not recommended.
    • 4mm of spacers are needed to compensate for the missing sprocket.
    • Because you can't fit the spacers under the cassette lockring, you need to fit all the spacer/s behind the large sprocket.
    • This has the effect of moving the sprockets to the right (toward the frame) by about 1.75mm so your gears would need significant adjustment.
    • It also leaves a large gap between the large sprocket and the spokes - might not cause direct trouble but looks like it could be a bit of a chain swallower.
  • Our policy? Stock and sell 7 speed cassette wheels when needed rather than making to with only 8 speed wheels in stock.