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Shredded drive side crank thread

SewinmanSewinman Posts: 2,131
edited January 2013 in Commuting chat
:cry:

I swapped pedals yesterday and obviously managed to cross-thread the pedal. After 5 mins of riding there was a wobble, so I headed home to swap bikes. Took a look and the thread was completely gone in the crank arm and the pedal forlornly flopped onto the street. I imagine a new chainset is required...so wondered roughly how much is it going to cost to fix at an LBS? Just so I don't get ripped off.

Its a Trek 1.2, so I won't be buying an expensive chainset.

:cry:

Posts

  • rolf_frolf_f Posts: 16,015
    Naaah, you can get these helicoil things that go into the crankarm to restore the thread. Just take it to the LBS. Should be cheap.
    Faster than a tent.......
  • spasypaddyspasypaddy Posts: 5,731
    should be fixable in the short term but id consider eyeing up a sram apex chainset. great value for money
  • SewinmanSewinman Posts: 2,131
    Do the Helicoils last long?

    Thanks for the advice.
  • SewinmanSewinman Posts: 2,131
    spasypaddy wrote:
    should be fixable in the short term but id consider eyeing up a sram apex chainset. great value for money

    Presumably that would not work with a Shimano Sora chainset etc?
  • Sewinman wrote:
    Do the Helicoils last long?

    Thanks for the advice.
    Yes. Could even be tougher than the original steel spindle -> alloy crank.
    mroli wrote:
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  • itboffinitboffin Posts: 19,847
    I'm pretty sure you need a new bike
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  • spasypaddyspasypaddy Posts: 5,731
    Sewinman wrote:
    spasypaddy wrote:
    should be fixable in the short term but id consider eyeing up a sram apex chainset. great value for money

    Presumably that would not work with a Shimano Sora chainset etc?
    is it a double? if so then yes.
  • SewinmanSewinman Posts: 2,131
    I rang my local LBS and they had never heard of a helicoil and 'could not do anything' with broken threads.
  • Try a different shop, failing that any good small engineering firm will know and might have the tools - although the size is pretty bike specific.

    The tools needed are the Helicoils + the right tap and tool to put it in, it looks like this:

    http://www.ebay.co.uk/itm/Unior-Pedal-T ... vi-content
  • rolf_frolf_f Posts: 16,015
    Sewinman wrote:
    I rang my local LBS and they had never heard of a helicoil and 'could not do anything' with broken threads.

    Given even me, with my mechanical averageness, has heard of a helicoil then there is no way I'd trust a shop that hasn't heard of one to even fit a bell to my bike....... :lol:
    Faster than a tent.......
  • SewinmanSewinman Posts: 2,131
    Proving harder than I hoped...I tried 3 others and none of them do helicoils or seemed to not know what they were and said they would need to look at it. I spoke to Moores, Twickenham, Action Bikes, Whitton, The London Bicycle Repair Company, The Cut and Evans, The Cut.
  • pete_spete_s Posts: 213
    If you're not capable of doing a Helicoil yourself take it to a car mechanics. They'll be set-up to do it as they probably repair stripped spark plug threads from time to time. IIRC cranks are an M12 thread which I think is about the size of a spark plug. It should take no longer than 15 minutes for a competent mechanic to do it.

    It's not difficult to do yourself but can be expensive as you'll need to buy a special thread tap. You can buy kits for £35 if you do go down the route of repairing it yourself.
  • tgotbtgotb Posts: 4,714
    Sewinman wrote:
    Do the Helicoils last long?
    Yes, but you can't have children while using one...
    Pannier, 120rpm.
  • Wrath RobWrath Rob Posts: 2,918
    Sewinman wrote:
    Proving harder than I hoped...I tried 3 others and none of them do helicoils or seemed to not know what they were and said they would need to look at it. I spoke to Moores, Twickenham, Action Bikes, Whitton, The London Bicycle Repair Company, The Cut and Evans, The Cut.
    If you're SW London way you may also want to try Sigma Sport (Twickenham), Velosport (Putney) or Cycleworks (Southfields) before resorting to the car mechanics.
    FCN3: Titanium Qoroz.
  • rolf_frolf_f Posts: 16,015
    Sewinman wrote:
    Proving harder than I hoped...I tried 3 others and none of them do helicoils or seemed to not know what they were and said they would need to look at it. I spoke to Moores, Twickenham, Action Bikes, Whitton, The London Bicycle Repair Company, The Cut and Evans, The Cut.

    I forget you are in London. If you cross thread a crank in London you are supposed to sort it buy buying a new Dogma. Don't you know anything? :lol:
    tgotb wrote:
    Sewinman wrote:
    Do the Helicoils last long?
    Yes, but you can't have children while using one...

    Good point - maybe he just needs to ask his Missus!
    Faster than a tent.......
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