removing my cranks

[pliskin]

hey guys,
i have tried to remove the sram S 1250 cranks on my Enduro.
i had been told it was a simple as using a 10mm Allen Key to undo the cranks, then pull them apart.
.

wanting to convert the bike to a 10x1 setup.
im planning on removing the granny ring and then fit a new chain guide, hence the need to get the cranks off

the internal fitting moves about 3/4 of a full turn, but then it stops. i cant twist or pull the cranks apart , is there a simple step, technique or tool i'm missing ?
more information is the BB is a sram PF 30.

 

[Chil]

So I take it you've removed the chain altogether to avoid it getting in the way? If not do that first then you should just keep undoing the 10mm bolt until the crank arm comes of off the spline.

 

[C0na]

This May help:
http://forums.mtbr.com/29er-components/custom-sram-s-1250-crank-bolt-773222.html

 

[moorey]

What chil said. Starts off loose, then gets tight, but that how it should be. Unless you feel like you're bending your Allen key, keep going.

 

[T-Rex]

That's a self extracting crank.

Get a set of suitably sized circlip pliers and stick them in two of the holes in the outer cap, and rotate it about half a turn anti clockwise. If you don't have circlip plyers, you can ghetto it with two small nails and a pair of needle nose pliers.

Then get into the bolt with a 10mm allen key, and undo it. You will feel the 10mm come loose, then feel like it's getting tight again as it comes up against the cap. Keep cranking and eventually the bolt pulls the crank arm off the spline.

When reassembling, use plenty of grease on the spline, so it will come apart nice and easy next time.

 

[rone]

That's a self extracting crank.

Get a set of suitably sized circlip pliers and stick them in two of the holes in the outer cap, and rotate it about half a turn anti clockwise. If you don't have circlip plyers, you can ghetto it with two small nails and a pair of needle nose pliers.

Then get into the bolt with a 10mm allen key, and undo it. You will feel the 10mm come loose, then feel like it's getting tight again as it comes up against the cap. Keep cranking and eventually the bolt pulls the crank arm off the spline.

When reassembling, use plenty of grease on the spline, so it will come apart nice and easy next time.

I fail to see what undoing the extractor cap 1/2 a turn will achieve, other than increasing the risk of stripping the outer thread.

OP - use the pin spanner to ensure the outer cap is tight before attempting to remove crank.

 

[The Duckmeister]

I fail to see what undoing the extractor cap 1/2 a turn will achieve, other than increasing the risk of stripping the outer thread.

OP - use the pin spanner to ensure the outer cap is tight before attempting to remove crank.

100% agreeance here.

Some self extracting cranks have a left-hand thread on the outer ring, so it opposes the crank bolt & can't unwind with the bolt. Quite sensible. It's unfortunate that not many are actually made this way.

 

[Capt.Gumby]

I have the same cranks and taken them off many times, ie, BB30 replacement. No need to touch the extractor cap or whatever it is. Just go hard with the allen key, it will eventually come off (I have even given the allen key nudge with a rubber mallet when I first took it off as it was on so tight from the factory fitout)

 

[moorey]

I have the same cranks and taken them off many times, ie, BB30 replacement. No need to touch the extractor cap or whatever it is. Just go hard with the allen key, it will eventually come off (I have even given the allen key nudge with a rubber mallet when I first took it off as it was on so tight from the factory fitout)

Same. Never had to do anything except undo the Allen key.

 

[pliskin]

thanks for that everyone.

tried it when i got home last night.
as moorey said, it started off loose then tightened up again. just kept going and it come off eventually.



hopefully will get it all back together tomorrow, then take it for a test ride.

 

[T-Rex]

I fail to see what undoing the extractor cap 1/2 a turn will achieve, other than increasing the risk of stripping the outer thread.

OP - use the pin spanner to ensure the outer cap is tight before attempting to remove crank.

100% agreeance here.

Some self extracting cranks have a left-hand thread on the outer ring, so it opposes the crank bolt & can't unwind with the bolt. Quite sensible. It's unfortunate that not many are actually made this way.

Same. Never had to do anything except undo the Allen key.

The reason I like to back the outer cap out a bit is so I can feel what's going on with the bolt. If the cap is done up hard against the bolt you don't get a good feel for the bolt coming loose when you try to undo it. And half a turn out won't cause the cap to get stripped out when you undo the bolt.

 

[rone]

And half a turn out won't cause the cap to get stripped out when you undo the bolt.

Oh but it will Mr Crank Whisperer.

 

[The Duckmeister]

The reason I like to back the outer cap out a bit is so I can feel what's going on with the bolt. If the cap is done up hard against the bolt you don't get a good feel for the bolt coming loose when you try to undo it. And half a turn out won't cause the cap to get stripped out when you undo the bolt.

Every single self-extracting crankset I've met in my professional life has had some amount of free space between the bolt and the fully-tensioned extraction cap. There is absolutely no sensible reason to need to loosen the cap.

In fact, unless it's one of the previously mentioned rarities with an opposed thread, you should ensure the cap is actually snugged down before loosening the main bolt.

 

[MARKL]

I am not a big fan of the self extracting style crank...previous experience with cranks being too excited about self extracting whilst riding. But seriously if half a turn is going to cause them to implode....well you don't want that shit on your bike!