Disc rotor rubbing on mount (Now with fix!)

graemevet
graemevet Posts: 61
edited October 2016 in Workshop
So I've successfully run 650b MTB wheels on my CX bike for months. 135mm spacing, center lock rotors. Shimano hubs.

I've now got a new set of lightweight 650b wheels but when I fit them the disc rotor seems to sit 1mm outboard of where it used to and rubs on the IS mounting bolts no matter how much I adjust them.

Is there variation in disc position from hub to hub? Would it be poor engineering to shave 1mm off the IS mount adapter or have I missed an easy alternative fix?

Thanks in advance.

Graeme

Comments

  • The Rookie
    The Rookie Posts: 27,812
    Yes different hubs do put the disc in different places, I just had to buy new wheels on a reframe for the exact same added, they are built to a 'convention' not a standard.

    If it's just rubbing the bolt tips (?) then get some shorter bolts perhaps by an mm or two, or fit an extra washer under the head to move them out a tad perhaps.
    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.
  • graemevet
    graemevet Posts: 61
    Thanks. I'm hoping to find an engineering solution as I really want to use these new wheels with the current frame. I have a spare IS adapter so I'll machine 0.5mm off that and see it that helps. The tolerances seem really tight at the best of times!

    Graeme
  • The Rookie
    The Rookie Posts: 27,812
    Novatech hub by any chance? That's what caused my problem. Were fine on 3 bikes and no good on the fourth!
    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.
  • graemevet
    graemevet Posts: 61
    The Rookie wrote:
    Novatech hub by any chance? That's what caused my problem. Were fine on 3 bikes and no good on the fourth!

    Yep! Did you have any luck in the end? or do I have to accept I've dropped cash on useless wheels? I'm in the process of getting a machine shop to shave 0.5mm off the IS adapter and I think that'll fix the issue.

    Graeme
  • The Rookie
    The Rookie Posts: 27,812
    The Novatech hub was on the old wheels when I reframed the bike, so sped up the new hubs for the new frame and swapped these onto another bike that needed better wheels and sold those ones on.
    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.
  • graemevet
    graemevet Posts: 61
    Success!!!

    In desperation to use my new wheels and not send them back I tried a few things:
    1) brute force aligning the calliper - FAILED!
    2) Filing down the IS mount adapter - failed, cut finger and managed to mash a spare mount
    3) Swapped the Avid BB5 calliper for TRP Spyre calliper (thanks Wiggle next day delivery!)

    TRPs fit perfectly, really nice quality and much better power and modulation. Sadly the bike now has BB5 on the front and Spyre on the rear. My OCD means I'll need to by another Spyre to complete the set.

    I'm a happy bunny today, who knew how stressful a bit of bike pimping could be!

    Graeme

Categories