Crank Repair Advice

[Gill]

Last fall through my own dumbassness I stripped the drive side (silver) crank on my Clem. LBS tapped/threaded insert put the pedal back on and off I went with no problems since. I recently asked a bike mechanic if he thought this was a good, permanent solution and he said, “Dude, if it was me I’d definitely get a new crank” (said with a slightly raised eyebrow  so I’d know he was serious). So in deciding what to do if anyone here has experience with this sort of thing or a reasoned opinion I’d be grateful to hear it.

Decision factors to consider:
I check often and pedal looks/feels fine. 

Keeping stuff out of landfills worthy goal
Depedaling (is that a word?) was painful want to avoid going forward.
New cranks don’t come easy

Questions:
How confident should I be with a repair?
Will changing out pedals compromise?
Should I have machine shop redo lbs repair, assuming skilled machinist with sophisticated machinery will produce best result?

Should I just get a new crank?

Thanks
Gill
Gloucester MA

 

[Elton Lance]

Most likely, they either ran a pedal tap through it to repair the threads or installed a helicoil.  If they did the former, it’s hard to say what the resulting threads are like.  

If they did the latter, and installed it properly, you should be fine. The helicoil tap is oversized, so you get fresh threading, and the helicoil is installed with strong threadlocker (i.e. red loctite or the like).  Keep the pedal threads greased and you are good to go.  

If they did not install a helicoil and it fails again, you can always install a helicoil at that time.  It should't be necessary to replace the crank arm unless there is other damage to the arm or tapers.

 

Elton Lance

Vero Beach, FL

--
You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group.
To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bun...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/121ebc25-a6c0-42f3-9ad2-2d15909f8acdn%40googlegroups.com.

[Jon Dukeman]

A good bike shop should be able to drill out the crank, tap the crank with helicoil tap  install a helicoil with loctite and reinstall your pedal.

Good as new.

--

[Jon Dukeman]

They used to sell a kit with the drill for the helicoil, helicoil tap and the helicoil.

[Joe Bernard]

While I understand that some folks would use this as a reason to buy new cranks - note your advisor said "if it was me" - I think you're good to go with the repair. Basically it's metal inserted into metal and there's no reason to believe it'll un-insert itself; keep and eye on it, listen for clicks and pedal on! 

[brendonoid]

I have ridden a tapped helicoiled crank for 8+ years with no issues. As others have said, if it was done properly there is no issue.

Sounds like bike shop dude wanted to sell a new crank! :P