Take the 2-minute tour ×
Bicycles Stack Exchange is a question and answer site for people who build and repair bicycles, people who train cycling, or commute on bicycles. It's 100% free, no registration required.

I've part stripped, and ultimately crossed the thread on my crank and can't remove my pedal now. This was done whilst riding and then trying to remove the pedal from the damaged crank. I figure the crank is toast but I want to remove the pedal without damaging it. Does anyone have any simple way to do that? My best theory at the moment is to use a hack saw to cut through and then either use a chisel to widen the gap or to then make another cut to free the pedal completely.

The main reason I haven't just done that is that I'm worried about damaging the pedals threads. I want to continue using this set of pedals.

Pedal wobbling about in crank

Here is a picture of the pedal, it wobbles about in the crank but I haven't managed to pull it out. I tried pulling the pedal while someone undid the pedal but the thread appears to be too screwed up.

share|improve this question

3 Answers 3

up vote 2 down vote accepted

I'm guessing the pedal is toast too, but if I wanted to try to save it (and it refused to come out with simply a wrench and a hammer -- counter-clockwise on the right, clockwise on the left) I'd get out my trusty Dremel and make a slot or two in the crank, parallel to the pedal shaft. (It won't hurt if you nick the pedal threads a little bit.) Then drive a small cold chisel into the slots to spread them a bit.

(I do wonder how you managed to cross-thread the pedal and then ride on it.)

share|improve this answer
    
+1 for great minds think alike.. :) –  zenbike Jul 23 '11 at 16:54
    
I didn't cross thread the pedal before, that was trying to remove it. Essentially assume too much torque or weight through the pedal stripped the threads. I think this situation was started by the bike having been supplied with the pedals massively over tightened. –  Colin Newell Jul 23 '11 at 16:58
    
It's vaguely possible the pedal was overtightened, but more likely it was cross-threaded on installation, and over-tightening was done in an attempt to "fix" this. If this is a new bike, and you haven't touched the pedals, it's a manufacturing defect. Otherwise, whoever installed the pedals screwed up. –  Daniel R Hicks Jul 23 '11 at 18:16
    
I actually used a chisel and hacksaw but essentially it worked fine. I don't think the cross threading happened until after the crank was bust. That was more a side effect of trying to get the pedal out of a crank with slightly stripped threads. –  Colin Newell Jul 25 '11 at 9:38
    
It's basically unheard of for a pedal-to-crank connection to "just go bad". Something was wrong with it from the start, or the pedal would not have worked loose. –  Daniel R Hicks Jul 25 '11 at 17:12

Your best option is to put pressure on the back of the pedal spindle and try to thread it out. If that isn't working, since it sounds as if you have tried that, then cutting is likely your best bet. But the thread on the pedal is very likely damaged as well.

I'm not sure I'd trust using them in a new crank.

share|improve this answer
    
The pedals threads are a much stronger material I think. My cranks at the moment feel like butter by comparison ;) I'm hoping the pedal is still okay. –  Colin Newell Jul 23 '11 at 17:00
    
I hope so, too, for your sake. I wouldn't count on it too much though. And if the threads are even slightly damaged, you will ruin a new crank, too. So be careful. :) –  zenbike Jul 23 '11 at 17:32
1  
The pedal's threads are steel, the crank aluminum. If you want to destroy the crank, then the hacksaw (or Dremel) will work. Just don't cut all the way through. Use a chisel or screwdriver driven into the slot you've cut to break the final bit of aluminum. If you want to try to save the crank, then you might be able to work the pedal out as listed above and then have a "heli-coil" installed. That's a threaded insert. If the crank is not a high-end piece; I'd just trash it and find another. Remember, Left pedals are threaded backwards. –  M. Werner Jul 23 '11 at 21:04
    
@M. Werner: Does steel not accept damage? I agree that it is possible, and worthwhile, to try to save it, but do not make the mistake of assuming that it can be saved, for certain. Too many times I've seen someone try to reuse a pedal, bolt, or spoke which was "ok", "Good enough", or "only a little damaged", and destroy a perfectly good, new, aluminum part trying to make it work. I'm not saying it can't be reused. I'm saying examine it carefully, and if there is the smallest doubt, replace the pedal, rather than risk the new crank winding up in Shimano heaven with the old crank. –  zenbike Jul 24 '11 at 2:56
1  
@M. Werner: If you disagree, that is fine. But post your own answer as an answer, not as a comment on mine, please. –  zenbike Jul 24 '11 at 2:57

EDIT: I re-read and you mean the pedal! not the crank, sorry for the confusion...

The pedal is probably ruined, and I doubt you can re-use it, a damaged thread is unrecoverable, but depending on the pedal, you can unscrue parts of it to salvage.

Below is my mistaken answer about removing a crank:

This happened to me recently, and my solution was to hammer the crank (knowing that it will become useless, — it was anyway, since the threads were destroyed).

The way I did it was to place the crank (the part that connects to the bottom bracket) on top of a vice and then hammer it hard (I mean hard, a soft blow won't work). Hammer as much as you can until it gets out. The main problem with this method is that it may ruin the bottom bracket.

The objective is to deform the crank so that it comes out.

From my experience, a metal crank is harder to remove, whereas an aluminum one is easier.

Also, (I can't really tell from the image you posted) if the crack has a plastic surrounding it, remove it, because hammering with the plastic cover won't have the same effect as without it!

On one of my attempts, I sawed the crank hoping to make it fragile enough for it to come out, but trust me, it doesn't really work and this will most definitely ruin the bottom bracket...

Finally, and if none of the previous worked, you can remove the bottom bracket (BB) from the frame (depending on the BB type, the old ones can be removed), you can use a pipe wide enough to fit around the BB, and hammer the pipe so it loosens the crank. This one is the toughest method and I've one crank that will be subjected to this method when I return from my holidays.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.