Fixing a stripped pedal thread

SimonAH
SimonAH Posts: 3,730
edited March 2011 in Commuting chat
Has anyone ever had a crank arm helicoiled to repair a borked thread? I've got one knackered pedal-thread and rather than shell out on a new crankset I thought I might see if I can find a local engineering firm to helicoil it (or failing that retreat to the workshop in goggles and braze the sucker in for good) :evil:
FCN 5 belt driven fixie for city bits
CAADX 105 beastie for bumpy bits
Litespeed L3 for Strava bits

Smoke me a kipper, I'll be back for breakfast.

Comments

  • UndercoverElephant
    UndercoverElephant Posts: 5,796
    If you have access to a tap and die set, you should be able to re-tap the thread in the correct way. Once that's done, the pedal should go in properly.
    Sun - Rain - Snow
  • nicklouse
    nicklouse Posts: 50,675
    most good LBSs will have a set of pedal thread savers.

    its a common and easy fix.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • stevec205gti
    stevec205gti Posts: 366
    Depending on the crank design and how shagged the thread is, you could just try winding an old/cheap pedal from the back. I'd slot the thread in the pedal to help clean the crank arm thread up.
    Has the head wind picked up or the tail wind dropped off???
  • SimonAH
    SimonAH Posts: 3,730
    Thanks for the advice folks, unfortunately I can't simply re-tap as about half of the thread length has sheered off the hole wall. This 'threadsaver' thing sounds a lot like a helicoil? I'll give the LBS s call tomorrow.
    FCN 5 belt driven fixie for city bits
    CAADX 105 beastie for bumpy bits
    Litespeed L3 for Strava bits

    Smoke me a kipper, I'll be back for breakfast.
  • SimonAH
    SimonAH Posts: 3,730
    Drat, just spoke to the LBS and they can re-tap but not helicoil. It's 9/16" - anyone know the thread pitch? UNF?
    FCN 5 belt driven fixie for city bits
    CAADX 105 beastie for bumpy bits
    Litespeed L3 for Strava bits

    Smoke me a kipper, I'll be back for breakfast.
  • Blue Meanie
    Blue Meanie Posts: 495
    9/16" @ 20tpi (thread per inch)

    You have to oversize, then tap a new thread, then insert helicoil - can be bought from Machine Mart, although they don't (currently) seem to have any online (only metric) :(
    FCN16 - 1970 BSA Wayfarer

    FCN4 - Fixie Inc
  • gtvlusso
    gtvlusso Posts: 5,112
    try: www.argoscycles.co.uk in Brizzle.

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