Crown race bigger diameter than steerer tube ???

nickfrog
nickfrog Posts: 610
edited January 2010 in MTB workshop & tech
Hello,

My LBS is putting my bike together on monday as it's much cheaper than me braking most parts.

However, as I was preparing the bits to give him, I tried and put the crown race down the fork's steerer and it went down right to the crown without any resistance and sits flush with the crown without being locked there. Is this normal? How do they normally stay in position ?
Is something missing at the base of my fork's steerer tube?
Would it be because the crown race is from an integrated headset (that came with the frame) and they don't "lock" to the fork?

Thanks for the guidance.

Cheers

Nick
2007 Commencal NUTS5 Superteam

Comments

  • supersonic
    supersonic Posts: 82,708
    They are an intereference fit ie are pressed on to a gradually tapering out steerer. It is not a good thing if they just drop on.

    See here:

    http://www.sheldonbrown.com/headsets.html
    GT ZASKAR CARBON TEAM

    VOODOO CANZO

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  • nicklouse
    nicklouse Posts: 50,675
    some can be pressed on as they are split.

    does it rattle on the fork, ie way to big?

    or?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • nickfrog
    nickfrog Posts: 610
    I don't think they are split. I can feel the effect of the tapper at the bottom of the steerer where there is hardly any play when fully down (difficult to measure, maybe a tenth of a mm?? or less). BUT, they're clearly isn't a snug contact, even at the bottom, where the crown race diameter is more or less equal to the steerer diameter so it won't stay down.
    Is the steerer damaged or the crown race damaged?
    Any solutions ?
    Pics attached.
    Cheers.

    jucppi.jpg
    2007 Commencal NUTS5 Superteam
  • nicklouse
    nicklouse Posts: 50,675
    Ah neither is new i see.

    yes it can happen. make the LBS aware of it and they may do something with some form of stud lock or they think it is fine or they may have another suitable race that is a better fit.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • nickfrog
    nickfrog Posts: 610
    Thanks Nick. Just been to the LBS and they reckon it's the wrong race for the headset anyway as the bearing does not fit flush. (the head set came with the frame of ebay). They have an integrated headset in stock at 20 quid which is a better bet I think and I'll get some money back from the seller against his old headset. They tried the new race by end and it's fine on the fork (as in they will have to press it in, as normal).
    Only prob is compatibility as I think it's a minefield. On the Commencal site they say Campy style and I am not sure what that means... I'll know more on Monday when they try and put it together as I only brought the fork and headset to the shop, not the frame...
    2007 Commencal NUTS5 Superteam

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