Removing DA 7700 cranks

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Removing DA 7700 cranks

Postby wardie » Sat Jan 25, 2014 8:55 am

Hi

I'm trying to remove a set of DA 7700 cranks from an old bike of mine.

On the drive side there is a hex bolt (about 9mm) which I have removed. On the non-drive side is a similar sized hex bolt but it only loosens about a 1/4 of a turn before tightening again.

Any ideas please?

Thanks

Mike
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by BNA » Sat Jan 25, 2014 9:38 am

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Re: Removing DA 7700 cranks

Postby KGB » Sat Jan 25, 2014 9:38 am

Octalink right? Does the bolt have a self-removing collar on it? Some will basically attach the bolt to the crank arm so as you wind the bolt out, it pulls the crank off the spline at the same time. In this case it would be like you describe, undo the bolt slightly then it becomes stiff again as you start the pull the crank.
It's odd to have this on one side and not the other though.
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Re: Removing DA 7700 cranks

Postby Dragster1 » Sat Jan 25, 2014 9:43 am

try and spray crc in there and go backwards and forwards a few times. See if it loosens,try not to wind it straight out if it is very tight
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Re: Removing DA 7700 cranks

Postby wardie » Sat Jan 25, 2014 10:31 am

Yes it's an Octalink.

Do you mean the nut on the non-drive side?
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Re: Removing DA 7700 cranks

Postby KGB » Sat Jan 25, 2014 11:42 am

Does the collar/dust cover around the head of the bolt look the same on each side?
I was thinking the difficult one may be a self extracting collar -SEE HERE for a Part Tool link explaining self extracting bolts/collars.
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Re: Removing DA 7700 cranks

Postby wardie » Sat Jan 25, 2014 12:26 pm

Looks definitely like that. Sorry but I'm mechanically impaired. Should the hex bolt on the non-drive side come all the way out?

Photo of non-drive side:

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Drive side

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Re: Removing DA 7700 cranks

Postby Dragster1 » Sat Jan 25, 2014 3:29 pm

It should be a self extracting crank, make sure the dust cap is screwed all the way in or it will strip the thread and put some type of lubricant where the bolt rubs on the dust cap to make it easier. Then carefully unwind the allenkey bolt out.
Allen key bolt
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Dust cap
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Re: Removing DA 7700 cranks

Postby wardie » Sat Jan 25, 2014 4:02 pm

Thanks Dragster. Is that drive side or non. The one on the non only turns about half a turn before stopping.
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Re: Removing DA 7700 cranks

Postby Dragster1 » Sat Jan 25, 2014 5:29 pm

wardie wrote:Thanks Dragster. Is that drive side or non. The one on the non only turns about half a turn before stopping.

Your drive side arm doesn't have a steel dust cap in it for some reason or another probably just a rubber seal. you should be able to use the non drive side dust cap to remove the drive side arm also. you need a good allen key socket on a breaker bar, load it up and give it a hard wack with your hand, the whole arm and bolt should come off in one piece. Try not to over do it the threads in the alloy arm are weak and strip easily.
If you haven't done much of this type of work, another way which would be easier is removing the dust cap and the bolt using an arm puller, but you need to remove the dust cap first in order to remove the allen key bolt last.
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