How affective is he...
 

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[Closed] How affective is helicoiling a crank

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Anyone got any real world experience on how effective a helicoiled thread on the drive side crank pedal thread holds in an environment where pedal strike is likely?

I have recently stripped 2 drive side crank arm pedal threads after pedal strike. The first was a 6 year old xtr crank that had taken some serious hits over the years, being through a few sets of pedals and was kind of not a surprise, but the most recent was its replacement 6 month old xt crank that still looks pretty new and to be fair I was a little disappointed that it went so easily.

A mate suggested a helicoil fix rather than new crank and he has done one on a cx bike but this is a whole different world to rock and root mountain biking, do they hold or am I just throwing good money after bad.


 
Posted : 17/05/2018 2:59 pm
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In my experience and to my knowledge, a heli coiled thread should be stronger that than a plain thread, particularly in aluminium, if done correctly.


 
Posted : 17/05/2018 3:02 pm
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As above mentioned: heli coil is strong. Never used it on a crank - but in other "aluminium" locations.

For me, crank: sounds like it's worth trying it.


 
Posted : 17/05/2018 3:21 pm
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Well I've heli-colied a cylinder head stud in a highly tuned Honda Type R engine before and that held, so I see no reason why it would be any different in a crank arm


 
Posted : 17/05/2018 3:22 pm
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Had a couple done on Shimano cranks over the years, been spot on.


 
Posted : 17/05/2018 3:26 pm
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perfect for the job HOWEVER as i said on the other thread you need someone with the tools and skills to do the job .

speak to jamie porter - he has the Relevent Taps and the engineering tools to do it.

9 times out of 10 especially if you have done it by clipping pedals running the black and decker through will just result in you helicoiling a wonky thread in place !


 
Posted : 17/05/2018 3:33 pm
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I have had cranks helicoiled and it was great. Not failed yet.


 
Posted : 17/05/2018 3:40 pm
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Great thanks for the responses seems it’s work a go.


 
Posted : 17/05/2018 4:51 pm
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Yep, had mine done a Wheelbase, £20  ridden plenty of miles and it's been spot on since.


 
Posted : 17/05/2018 5:14 pm
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Definitely do it. I've had cranks shortened and helicoiled for tandems and they take a lot of torque. No issues.


 
Posted : 17/05/2018 7:03 pm
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Weird how a pedal strike would strip a thread.


 
Posted : 17/05/2018 7:12 pm
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I had some cranks that where done.  No problems was done by someone with the full kit.


 
Posted : 17/05/2018 8:49 pm
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Ill do it for you over the bh weekend if you bring it doen. It will cost you a packet of those caramel digestive biscuits. And a pint of milk for the tea.


 
Posted : 17/05/2018 9:14 pm
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Not bothered helicoiling them but have killed a couple of xt cranks this way. On both occasions found a second hand replacement from a person who had killed the other side to me 🙂

I'm sure I read somewhere that they are more susceptible to failure than say the SLX due to manufacturing difference. As in the xt is threaded rather than a threaded insert or some thing.*

*May be totally wrong


 
Posted : 17/05/2018 9:33 pm
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Porter_jamie that’s a bargain, I’d need to buy 2 packs because I’d have eaten the first by the time I got to yours. I’m not going to find out you live in the SW of Uk and it’s like a 10 hr drive.


 
Posted : 17/05/2018 10:17 pm
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Unit is in essex


 
Posted : 17/05/2018 10:30 pm

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