Stripping fun...

jimo746

Gold Trader
MacRetro Rider
Orange 🍊 Fan
Feedback
View
Not really... just tried removing the Shimano 500EX chainset from my road frame, and managed to strip the threads from the non-drive side crank :roll:
So now the crank extractor has nothing to thread onto, therefore I cannot remove the crank.
I think I can still remove the bottom bracket (complete with crank arm attached) though, but not tried it yet.

Is the crank arm thread repairable?
Is there another "puller" I could use to remove the crank arm?
I'm guessing 500EX cranks arms are like rocking horse pooh to find?
Is it best to just find another silver 170mm square taper crank arm and live with mismatched cranks? (tbh I think it will bug me whenever I ride it)
 
There is another tool that holds the crank from behind while pushing in the center just like a regular crank extractor. I don't know what it's called in english but I'll try to find a photo.
 
Found it!

saca_polias.jpg
 
Firstly, just try riding the bike up and down the street a bit, particularly putting some pressure on the pedals and it might loosen the crank before resorting to 'tools':
2-arm bearing-puller (as above) or fork-type ball-joint splitter - both from car parts / tool shops.
In terms of repairing thread on crank there's little you can do I'm afraid.
You might be lucky in terms of finding a 500Ex crank - someone might have some. Plenty of people ride mis-matched cranks
 
there is one option for repairing the crank arm thread. it is called i believe a "steiner" tool. basically it looks similar to a normal crank extractor but the first part doesn't screw in as normal as it has a coarse thread tap on it.

this means that you gradually screw in the first part of the tool and it cuts its own thread as it goes, effectively giving you an oversize thread, then you screw in the second part of the tool which is similar to a normal extractor.

the crank arm should then come off as normal.

there is one downside, if you then re use the crank arm and then have to remove it again for general maintenance you will need to use the tool again as a normal extractor won't fit, although trust me it will easy the second time!

one of my lx cranks has this thread cut in it.

i know Gary at GA cycles in southampton has this tool. you would need to find an old school shop for this job as newer shops would simply never had any need for this tool.

also if you can remove the b/b with the arm attached which is possible depending on the b/b cup you have you should then beable to remove the axle from the crank arm by clamping the b/b cup in a vice and then carefully punching the axle out facing down towards the floor.


hope that helps.

:)
 
If you can remove the drive side crank and it is a conventional cup and cone BB then all is not lost. Remove the drive side crank. Remove the drive side cup and just whack the BB axle end with a hammer and punch on the non-drive side.
 
Hi, thanks for the replies. I was so annoyed at myself when the thread stripped... totally my own fault for not ensuring the extractor was fully screwed in before tightening it up :roll:

Anyway, now I've calmed down a bit I think I will first try and remove the bottom bracket and punch out the axle from the crank. Failing that I will get myself a puller and give that a try (could come in handy for car pulleys etc too :D ).
 
Back
Top