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-   -   Stuck crankset removal? (https://www.bikeforums.net/bicycle-mechanics/468477-stuck-crankset-removal.html)

oilman_15106 09-22-08 08:02 AM

Stuck crankset removal?
 
Daughter's friend's bike needs a new bb. The drive side crank is stuck. The threads for insertion of a bb removal tool are stripped(no by me). Square taper.

Here is what I have done so far: Soaked the thing in CRC and tried to pound it off from the reverse side. No luck. If all else fails, I guess I could cut the bb spindle and drive the remaining part out. BB is shot anyway.

Any other ideas? Thanks.

dabac 09-22-08 09:23 AM

how many arms are there on the chain ring carrier? If it's a 4-arm carrier then a 2-arm generic gear/bearing puller can do the trick.
Otherwise if you're not worried about the bb you can use one of those wedge-shaped forks used by car mechanics to break open ball joints in car steering assemblies. Simply point it in between bb cup and crank and give it a good whack or two

HillRider 09-22-08 09:46 AM

Cutting the spindle is going to be difficult as they are quite hard. I don't know if a regular hacksaw blade will cut them so don't be surprised if it ruins several blades. You may need a carbide blade to do the job.

G piny parnas 09-22-08 01:24 PM

a really cheap gear puller might work or a steering wheel pulller or can you force the cup unloose some other way --- I remember jamming a wedge in between the broken arm and cup and
slowly screwing it out--- cut into my drinking time but it worked

kycycler 09-22-08 01:57 PM

Go to the auto supply store and get what is called a pickle fork. This is the tool that is used for removing ball joints. Place the forked end between the crank and BB. Now hit the tool HARD with a hammer. this should remove the crank. Don't forget to remove the bolt form the crank first.

oilman_15106 09-24-08 08:25 AM

Thanks for the responses. Will try to borrow a pickle fork to keep the cost of this thing in check.

arborohs 09-24-08 11:54 AM

As the threads are gone, why not just ride that thing until it falls off. It's no good now anyway.

G piny parnas 09-24-08 12:52 PM


Originally Posted by arborohs (Post 7534669)
As the threads are gone, why not just ride that thing until it falls off. It's no good now anyway.

dude..... wheres the beer........

tommyd49 09-24-08 02:57 PM

Wedge a chisel between the crank and the BB which is about the thickness of the gap. If it's the right thickness you should be able to either press down on it or hit it with a mallet. You'll need to take the chisel in and put it back to its original position every time you do about a quarter turn, so it's a slow process, but it works.

mike_s 09-24-08 05:53 PM

(I'm assuming an aluminum alloy crank)

Al has about twice the coefficient of thermal expansion vs. steel (heat it up, the crank will expand more than the spindle). You could take a propane torch to the crank before trying to pound it out.

oilman_15106 09-29-08 08:38 AM

Update: Pickle fork did not work! The stamped chainring design prevents getting both sides of the tool into a position for driving the thing off. Time to either borrow a saws-all or maybe the above idea on a torch would work. I have never had this much trouble with something like this. Also tried the chisel idea with no results. Have been soaking with PB Blaster which usually frees stuff up.

The chainring set is shot at this point and maybe I could cut off the stamped chainrings and then drive it out with the pickle fork? Thanks again.

oilman_15106 10-16-08 08:39 AM

Final update and now I know why I did not buy the LBS when I had a chance.

We tried everything to remove this chainring/crank arm(drive side). Final solution was to cut the chain ring with a welding torch and use an industrial strength gear puller to remove the remaining bit. The plastic shifter guide on the bottom of the bracket was melted in this process.

Bottom bracket finally removed and replaced. New crankset, chain, cables, guide and we are back in business. If this were charged by the hour for all the grief the bike which is a $100 bike on Craigslist needs to bring $300 to break even.

jgedwa 10-16-08 09:46 AM

Welcome to the club of us fools that don't know when to stop. It is not dishonorable to back away from a problem.

jim

p.s., I have a frame with a stuck seatpost on the stand now that may have 20 hours in it. From a bike I bought off CL for $35. Tells you something about how valuable my time is.


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