Fork Flex

The Northern Monkey
The Northern Monkey Posts: 19,174
edited May 2014 in MTB workshop & tech
I've upped my QR 1 1/8th Reba to 120mm from 100mm and noticed a fair bit of flex towards the left under braking.

The wheel seems sound, and I didn't notice any flex when running at 100mm.
I turned the wheel around in the dropouts and it still flexes to the left when compressed hard with the brake on.

Is the fork likely to flex/twist more at 120mm that 100mm?

I don't think it is much, but is exacerbated due to the tyre size by the looks of things!

Cheers
Santa Cruz Butcher

Comments

  • The Rookie
    The Rookie Posts: 27,812
    It will flex more at 120mm, though not by much, are the uppers and lowers both definitely 120mm compatible, you may have lost overlap in the bushes if they aren't.

    How can you turn the wheel round and still use the brake, or is it rim braked?
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • The Northern Monkey
    The Northern Monkey Posts: 19,174
    Sorry not with brake on... must have been writing 2 sentences and got lost half way through.

    Definitely 120mm compatible, they are 2012 all travel versions (internal spacers).

    Going to check the headset later, although I don't think that will cause flex in the fork leg!
    Santa Cruz Butcher
  • sanchez89
    sanchez89 Posts: 567
    is it the QR moving in the dropout? or the actual fork leg bending?
    2011 KHS Full Susser Carbon 29er Race Build
    Clank wrote:
    M'eh, I might just go back to zapping it with frikken lay-zur beeeems. And sharks.
  • The Northern Monkey
    The Northern Monkey Posts: 19,174
    Think it is resolved... cimbination of my headset not being tensioned properly and my qr not being tight enough...

    I shoukd really pay more attention when putting a bike together!
    Santa Cruz Butcher

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