Stripped crank arm ...
 

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[Closed] Stripped crank arm thread - probably silly question

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Hi all. Been a while since I posted here (work, family and guitars). Probably silly question - thread on left side crank arm has stripped bare (truvativ firex 3.1 - pedal fell off while riding last night). Is it possible/worth the hassle of getting LBS to re-thread or should I just buy and fit a new crank arm myself (and probably pedals)? 

The collective, sage advice of STW is much appreciated. 

Thanks 🙂


 
Posted : 04/05/2011 8:17 am
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there probably won't be enough thread left to re-tap it so that you have enough confidence in it
you could have it heli-coiled or a thread insert put in but it's probably cheaper to get a new LH crank arm


 
Posted : 04/05/2011 8:51 am
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You can drill it out and thread it to a larger size and then use a pedal insert to take it back down to the correct size.
The pedal inserts are available from framebuilding suppliers and are only a few pounds, however the taps to thread the new size will be expensive, so unless you know someone who has them it will definitely be cheaper to just replace the crank.
I'd be pretty amazed if you can find a bike shop that will do this for you - most will just tell you to buy a new one, which is fairly good advice.


 
Posted : 04/05/2011 9:15 am
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Thanks guys - a new crank arm certainly sounds like the path of least resistance.

Cheers!


 
Posted : 04/05/2011 11:01 am
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getting one to macth may be tricky, but I don't think many lbs have helicoils for this purpose.


 
Posted : 04/05/2011 11:05 am
 Taff
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Wouldn't go to a bike shop. An engineering firm will be cheaper. Alternatively - [url= http://shop.ebay.co.uk/i.html?_nkw=truvativ+firex&_sacat=0&_odkw=truvatic+firex&_osacat=0&_trksid=p3286.c0.m270.l1313 ]CLICKY[/url]


 
Posted : 04/05/2011 11:08 am
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This happened to me and my LBS put a helicoil in, has been ok so far and cheaper then new crank.


 
Posted : 04/05/2011 11:29 am
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+1 for helicoil. Any good bike shop should be able to do this. Had one in a crank for years.


 
Posted : 04/05/2011 11:53 am
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Cynic-al might have some glue that should fix it. 🙂


 
Posted : 04/05/2011 12:04 pm
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Thanks all - LBS can do me a deal on a replacement crank arm for £15. Feels like a bit of a result - maybe I can ride this weekend after all. Hoorah!


 
Posted : 04/05/2011 5:24 pm

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