Help - SRAM chainset removal

ROK ON · 01-09-2014 8:20pm #1

Hi

I am trying to remove a SRAM chainset from a bb.
I have used an 8mm Allen key to remove the nut from the centre of the crank arm.

However the crank arm will not budge from the spindle at all.
I have tried leverage and that won't budge it.

There appears to be nothing else that I can unscrew.
Any ideas? What could I be missing.

ROK ON · 01-09-2014 8:24pm

I have attached a picture.

Borderfox · 01-09-2014 8:34pm

ROK ON wrote: »

I have attached a picture.

A crank extractor fits into the thread in the hole to pull the crank off

ROK ON · 01-09-2014 8:44pm

Borderfox wrote: »

A crank extractor fits into the thread in the hole to pull the crank off

Ok
That would be necessary then?

I have checked sram YouTube videos and other videos concerning sram cranks and not one mentions a crank extractor. Strange.

Will any crank extractor do - I can't find a sram one on wiggle/bike24/crc.

Al Wright · 01-09-2014 9:30pm

From the picture it appears that crank spindle is hollow, therefore a standard crank extractor will not work, (nothing for the extractor screw to lever against). It appears that the crank is a straight spline engagement, so it should just slip off. It has probably seized over time. Try tapping out using wood wedges between crank and bottom bracket bearing face. (the risk of using a heavy screw driver is that the bearing seal could be damaged. It the intention is to replace bearings then this isn't an issue)
I'm not familiar with the Sram, but a similar looking arrangement uses the cover piece through which the 8mm Allen screw goes as an extractor. If there are fine threads on the inside of the crank between the outer edge and the spindle this might be the case. If the 8mm Allen screw has the bezel still fitted there is a chance that this is of that type.
Search Google for 'Self Extracting Crank Bolt' for a description.

ashleey · 01-09-2014 10:47pm

Something has gone wrong for you. The nut should stay with the crank arm and push the crank arm off the spindle. The nut is not removed from the arm. I would try to reassemble and check that you are turning the nut in the right direction? If not you are a bit stuck as the arm is still gripping the spindle with no method of loosening.

vertigo1976 · 01-09-2014 10:52pm

On my Sram force GXP crank, you leave the larger outer allen nut in place and as you loosen the inner 8mm one it self extracts the crank. Hope that makes sense.

The tax man · 01-09-2014 11:04pm

Thinking along the same lines as Al Wright. Self extracting type setup. Was there a threaded ring around the bolt that held the crank arm onto the BB spindle? When I first came across this setup I thought I had to remove the ring instead of leaving it in place.
http://www.parktool.com/blog/repair-help/self-extracting-or-one-key-release-systems

ROK ON · 01-09-2014 11:28pm

Thanks for the replies folks - I am attaching more pics.
You will see that there is a thread inside the crank arm.

This thread is not for the crank bolt - so I figure this is what I should thread the extractor tool to in order to unscrew the crank arm.

Would any store in Dublin have one of these - I figure bee cycles does as he bilt the bike - but he is out of commission at present.

ROK ON · 01-09-2014 11:30pm

More

J Madone · 02-09-2014 12:04am

ROK ON wrote: »

More

Your missing a cover piece that threads in over this.its not meant to be removed, do you still have it? Has a 10mm allen key hole. I would say you can get a spare off a sram dealer

The tax man · 02-09-2014 12:13am

I still reckon that thread is for a threaded cap(on left) that the main bolt pushes against to remove the arm.

J Madone · 02-09-2014 7:49am

The tax man wrote: »

I still reckon that thread is for a threaded cap(on left) that the main bolt pushes against to remove the arm.

Correct and right

ROK ON · 02-09-2014 8:49am

Guy
Thanks plenty.

What do I need to do now?
Get a replacement part, insert it and then remove the crank arm?

clog · 02-09-2014 9:11am

You can get crank pullers that will work with a hollow spline. Cyclus ones certainly have a fitting for hollow isis/octalink splines. At a push I have had success putting a small coin in the space and using puller against that.

This may work though as a replacement for the part you are missing.

http://www.chainreactioncycles.com/ie/en/fsa-megaexo-crank-screw-qr-14/rp-prod87643

Help - SRAM chainset removal

Comments