Helicoil Crank Arms?
- Thread starter dylan s
- Start date
Not sure how you will go helicoiling an insert in a carbon arm. Good luck. LBS might be worth a try too.
Ultra Lord
Hurts. Requires Money. And is nerdy.
You can get reverse helicoils. Abit exy though, notnirmally an on the shelf item either
Only if it is the non drive side.
You don't need to tap the carbon, they have metal inserts for the pedals. LBS doesn't have the gear.
Which is why I used the word insert in my reply. The insert is bonded to the carbon. Retapping will put load on that bond. Maybe.
link1896
Mr Greenfield
50% chance of success at best I feel.
I also have a shagged carbon sram crank, some prick scammed me. I should have looked closer at them considering it was a night time transaction. 50% of the thread is gone, should probably just super stud lock a pedal in and use on the trainer.
born-again-biker
Is looking for a 16" bar
http://www.timesert.com/html/install.html#A
These are a great product....but I think you'd be 'going where no man has been before' fitting one to CF....??
I think @link1896 nailed the odds.
These are a great product....but I think you'd be 'going where no man has been before' fitting one to CF....??
I think @link1896 nailed the odds.
Flow-Rider
Burner
Are the original crank inserts really thin ? other than that I can't see why you can't tap a thread in the insert for the helicoil. I've installed thousands of them over the years. If you know how to tap properly you can do it with minimal load on the crank arm.
SummitFever
Eats Squid
The alu inserts have a lot of meat to them. That's one of the reasons why the carbon cranks are not that light. Helicoil shouldn't be a problem. The torque of retapping for the helicoil will be insignificant compared to riding.
Sounds like no one has the kit needed to do it. Guess I'll call a bunch of shops, surely one has the tools to do a pedal tap. I don't much fancy forking out $200+ to buy my own https://www.jensonusa.com/Unior-Pedal-Tap-and-Bushing-Set
I won't be putting the cranks back on my bike, I'd just rather have them functioning in case I'm ever in a pinch and need a set of cranks asap. Its better than tossing a $400 set of cranks. But like SummitFever said the inserts have plenty of meat on them, it should be fine
slowmick
38-39"
Have torn the metal insert out of the end of an X0 carbon crank. It is not as big as you think. The failure was my own fault as i had a huge pedal strike shortly weeks before hand.
The insert came out landing a jump and the pedal disappeared into the bushes. I don't recommend it. I'd chalk it up to experience, buy yourself $150 of alloy cranks and then promptly forget all about cranks all together.
The insert came out landing a jump and the pedal disappeared into the bushes. I don't recommend it. I'd chalk it up to experience, buy yourself $150 of alloy cranks and then promptly forget all about cranks all together.
SummitFever
Eats Squid
Provided there is sufficient material that the enlarged helicoil threads are still in the alu then the helicoil repair will be significantly stronger than the original insert. You're replacing alu with steel. There is no special voodoo or magic involved. All the information is provided by the manufacturer so no guesswork is involved:
Helicoils are not only used for thread repair. They are often used to increase strength where there are size constraints on bolt diameter.
Also, tearing the insert out of a carbon crank just shows that the carbon part of the crank is crap.
The only reason not to do it is if cost and effort make it uneconomical.
It's not uncommon for car mechanics to tap new threads
Calvin27
Eats Squid
I worked at the AFS factory for about 3 years making these helicoil things. My specific project was to test whether you could make helicoil work for carbon applications with some changes to the design. You can do it reliably, but my guess would be to avoid any thin wall applications and/or high stiffness layups, which cranks I would classify as.