Need a new left sid...
 

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[Closed] Need a new left side Crank arm Shimano Hollowtech style

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Hi, please can you direct me to where I might be able to buy a new (left side) crank arm?
I'm still old school I'm afraid, so rather than buying a whole new crankset I'd like to get equivalent spare that would fit. 175mm length.
existing crankset is/was SLX M660, triple (thought I converted drive side to 1x11). anyway, yesterday I managed to strip the pedal out of the threads in the non-drive arm.
I've looked online and the vast majority seem to all be "E-bike specific" whatever that means, unless I'm spending upwards of 100 quid, whereas I was hoping to pick up something for 30-40?

I just need a good old simple shimano hollowtech compatible left arm- could be Deore or XT or whatever....

Or Are the 'E-bike' specific ones basically workable on left side anyway I wonder?

Thanks in advance


 
Posted : 22/07/2021 10:07 am
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Hopefully you can find someone with a knackered drive-side arm to sell you their NDS.

I could have helped if you were after a 170mm one.


 
Posted : 22/07/2021 10:10 am
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yeah cheers. Its the sort of thing I might have had spare too...
will ask in a couple of LBSs also.


 
Posted : 22/07/2021 1:14 pm
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Bit short on supply with the usual suspects but this may do the trick

https://www.hargrovescycles.co.uk/components/gears-drivetrain/shimano-deore-fc-m590-left-hand-crank-arm-in-silver--175-mm__18990?currency=GBP

Its from a 9 speed groupset but should be ok. I bought one of these in black to replace a snapped left arm from a 10spd deore set and it worked fine.


 
Posted : 22/07/2021 1:14 pm
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anyway, yesterday I managed to strip the pedal out of the threads in the non-drive arm.

Have you thought about just getting the thread fixed (tapped and inserted)?


 
Posted : 22/07/2021 1:16 pm
 poah
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Got one from bikester when I did the same thing.


 
Posted : 22/07/2021 1:27 pm
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Have you thought about just getting the thread fixed (tapped and inserted)?

On a related note - can you get the threads in crank bolt-holes repaired?


 
Posted : 22/07/2021 1:29 pm
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On a related note – can you get the threads in crank bolt-holes repaired?

The big self-extractor thread? No reason why not. Just need someone with the right tools, so might be a local engineering place rather than LBS


 
Posted : 22/07/2021 1:32 pm
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The big self-extractor thread?

Nah, the M7000 SLX chainset had threaded holes to put the chainring bolts in - and they must have been prone to stripping out 'cos they swiftly moved to direct mount for the next version.


 
Posted : 22/07/2021 1:37 pm
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Probably even more likely then tbh. Just need to know the thread size and there’ll be an insert available


 
Posted : 22/07/2021 1:38 pm
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I think I have one - I've got an assortment of half knackered cranks! I'll check after work for you.


 
Posted : 22/07/2021 1:41 pm
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@DenDennis - try the guy who does a repair on ebay, "Bicycle crank arm pedal thread repair service (for stripped/damaged threads)".
I had a spate of this issue (the history is here on the forum somewhere...) a few months back I'm happy with his service. My LBS said it was unrepairable and tried to sell me a new crank. They were wrong.


 
Posted : 22/07/2021 1:42 pm
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I can fix that for you! Drop me a PM 🙂


 
Posted : 22/07/2021 1:49 pm
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Hollowtech style? Sorry, thought you meant...

😆


 
Posted : 22/07/2021 2:07 pm
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I have a 175 m760. PM me if you want it.


 
Posted : 22/07/2021 2:40 pm
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I can fix that for you! Drop me a PM 🙂

Was that aimed at the OP or me?


 
Posted : 22/07/2021 5:06 pm
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Nah, the M7000 SLX chainset had threaded holes to put the chainring bolts in – and they must have been prone to stripping out ‘cos they swiftly moved to direct mount for the next version.

Seems possible.


 
Posted : 22/07/2021 5:27 pm
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Ive got one spare , in black, marked up as FC-M442/443 , think it came off a Mongoose Teocali ages ago. Its yours for the postage, I was due to bin it this week anyway.


 
Posted : 22/07/2021 6:40 pm
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I can fix that for you! Drop me a PM 🙂

Was that aimed at the OP or me?

The OP!

Having said that, I'm sure its possible to helicoil and repair the holes the crank bolts thread into. Would need to double check the pitch and depth, but Im sure there is a suitable tool available to do it.


 
Posted : 22/07/2021 6:42 pm
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I have repaired one of these before, for a workmate.I just bored out the damaged threads, turned up an insert and tapped it the correct thread, or maybe I thread cut it on the lathe. Anyway, nice tight fit and a couple of dutch keys to prevent the bush rotating in the crank arm and by all accounts it worked for years with no problem.


 
Posted : 22/07/2021 6:55 pm
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Cheers all for recommendations and advice.
Just to show the bit I'm after, it's this version of hollow tech BB crank.

slx crank arm

Out of interest, do the newer 1x12 Shimano direct mount cranks fit onto the same screw in BB cups?


 
Posted : 22/07/2021 8:43 pm
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Yes they do.


 
Posted : 22/07/2021 8:46 pm
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Cheers chaka, so if it came to it I could use old BB cups and fit new full 1x11 chainset or at least just the left arm?


 
Posted : 22/07/2021 8:48 pm
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MikeyP top man, arm arrived in post today! Thanks


 
Posted : 24/07/2021 9:35 am

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