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Loose Crank Arm


Balthazor

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I had the exact same problem last night, it IS the little washer that goes on the end of your BB, so your crank arm tightens up againts it and goes tight...

http://www.tartybikes.co.uk/product.php?pr...p;category_id=2 see the 2 thin silver washers slotted over the end of the BB slines? thats what you need...

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I have the exact same problem too.

Turned out that the crank fitting was being "eaten up", soft alu crank fitting against hard steel bb shaft. I have to use that coke can shim method. It worked, but the crank bolt spacer was pretty chewed up too. I was using the echo cnc crank for 6 months already and it failed in the third month. A senior rider told me that those echo cnc cranks are really soft cos another rider at my side spoilt his on the first ride. Has there anyone here with the same problems with echo cnc cranks?

I would be getting Modulo cranks next week. It's a Singapore brand, has anyone heard of it? I was told that it was damn stiff.

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I'd say the Echo CNC cranks are soft yes, mine has damage at the contact point of the arm and BB, but also the BB end looks mushroomed/bent so maybe new cranks and BB.

It's hard to explain but the BB splined part that goes into the crank arm seems to be level with the top of the inside of crank arm splines. So when the bolt is tightened up its not pressing the crank arm onto the BB fully so there is slight gap/movement.

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I'd say the Echo CNC cranks are soft yes, mine has damage at the contact point of the arm and BB, but also the BB end looks mushroomed/bent so maybe new cranks and BB.

It's hard to explain but the BB splined part that goes into the crank arm seems to be level with the top of the inside of crank arm splines. So when the bolt is tightened up its not pressing the crank arm onto the BB fully so there is slight gap/movement.

thats what the washer does... it stops it from moving right the way onto the BB, so the crank tightens upto the washer...

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My mate had the same problem, that problem was that the tapers on his cranks got so badly worn that the crank bolt bottomed out on the BB.

If they've been run loose, then you need new cranks because the tapers will be shot. Not all BBs need the spacers on the end By the way, and not all ISIS cranks bottom out onto the end of the BB.

Take the BB out and try to work out what it is, then you'll be able to tell whether it needs the spacer. Either way it sounds like new cranks time to me.

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