New bike - knackered thread

djwc
djwc Posts: 39
edited May 2015 in Workshop
I just bought a new bike online, and one of the threads for the allan bolt on the down tube is knackered (where you would put a bottle cage).

I was advised by the web shop I bought it from to take to my LBS to get them to re-do the thread, as I managed to get the bolt out using a pair of pliers.

Any idea how much this should / might cost? Also - is it possible to re-thread / repair a thread like this?

Comments

  • trailflow
    trailflow Posts: 1,311
    Was it your fault ? if no, why should you have to pay to fix it ?

    and yes its fixable. You can re-tap it or use a helicoil.
  • ai_1
    ai_1 Posts: 3,060
    Really depends what is wrong with the thread I would expect.
    I'm a bit confused what exactly the issue is.
    So, you're saying one of the bottle cage mount points has a damaged thread. There was a bolt in it which you've removed with a pliers. Why did you remove it with a pliers? Was it stuck and you ended up damaging the socket trying to free it then had to resort to pliers?
    Will a new bolt now not go into the thread or are you trying to use the bolt you extracted?
    What material is the frame?
    Did any material come out of the hole with the bolt (i.e. fragments of damaged thread or flakes of paint)?

    Typically there are 3 potential problems I can think of with a threaded hole:
    Badly formed thread
    Thread damaged due to over-tightening
    Paint or some other material clogging the thread

    Or you could have trouble getting a bolt into the hole because of damage to the bolt thread from any of the same 3 causes, or because it's the wrong thread.

    If it's a new bike I'd be a little uncertain about getting a local shop to do work on it without a commitment from the vendor that they will accept the bike back if this does not resolve the issue regardless of what the LBS has done. I certainly wouldn't be willing to pay for the repair if it was delivered that way.
  • djwc
    djwc Posts: 39
    No, not my fault. I won't have to pay to fix - they just said to take it to LBS and keep the receipt, they will then give me a voucher for that amount.

    It was just a bad thread, the bolt came out about 2-3mm with the allan key on my multi-tool, then got stuck. when I finally got it out, I saw why - the end of the bolt was a very odd shape, and the thread on it was virtually non-existant.

    I tried putting the bolts from the other holes into it, but they barely got 1mm in before the started to get stuck and I wasn't going to force them in.
  • ai_1
    ai_1 Posts: 3,060
    DJWC wrote:
    No, not my fault. I won't have to pay to fix - they just said to take it to LBS and keep the receipt, they will then give me a voucher for that amount.

    It was just a bad thread, the bolt came out about 2-3mm with the allan key on my multi-tool, then got stuck. when I finally got it out, I saw why - the end of the bolt was a very odd shape, and the thread on it was virtually non-existant.

    I tried putting the bolts from the other holes into it, but they barely got 1mm in before the started to get stuck and I wasn't going to force them in.
    It might be enough to just run a thread tap through it to re-cut the thread through the damaged portion. The threads would not be perfect but you'd get a bolt in and out and it would most likely be strong enough for a bottle cage. I presume that's what they are advising?
  • djwc
    djwc Posts: 39
    Yeah that's what they've suggested.
  • ai_1
    ai_1 Posts: 3,060
    DJWC wrote:
    Yeah that's what they've suggested.
    If the damage to the thread isn't too severe that should be fine. Still annoying on a new bike though! :(

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