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I'm taking my cranks off because I need to change my middle chain ring and I can't wriggle it off over the crank arm. So I can see a kind of dust cover which says 10mm and a tightening direction and also 8mm with a (opposite) tightening direction.
So do I use a 10mm allen key first and take off the black cover (opposite direction to the tightening direction) and then do the 8mm?
I'm asking because it's been done up very tight and before I put a bar on it I want to make sure I'm undoing the right thing first.
Thanks.
8mm anti clockwise. The 10mm holed black thing is the extractor cap.
Undo the inner 8mm in the normal direction (anti-clockwise). That will push against the black cover which functions as a self-extractor, and the crank will magically remove itself from the splines.
Rob
EDIT - I clearly type too slowly!!!
Ah, so I don't undo the 10mm. Ok, will give the 8mm a go, see if I can shift it. Normal undo-way, thanks very much indeed.
bommer is spot on,
I have always removed the 10mm extractor cap cleaned behind it and smeared a bit of grease on the threads and crank bolt, refitted it tightening it up until snug. Then using an 8 mm Allen key undone the crank bolt anti-clockwise.
Caution it can be very tight and goes with bang...
[url= http://www.parktool.com/repair/readhowto.asp?id=95#race ]Park Tool - Linky[/url]
I've got the crank off no problem.
I'm not going to touch the extractor cap for now, my allen keys aren't great and if it slips it will round off the bolt. That can wait until I buy a good quality set.
Thanks everyone!
That's interesting, I've put the crank back on - if I tighten it a lot, the cranks don't spin round as freely. What's going on? It's got a Hope BB - thought the cups of that were the bits that dictate pressure on the BB bearings?
No, the BB just sits there, the cranks should have some kind of bearing preload mechanism, but I'm not sure how the Raceface system works. Probably detailed in that Park tools instructional linked above.
Have you got spacers in there? Take them all out and put it together. Wang it up tight and then tap it to one side with a mallet. You should see a gap. Measure this or jam a stack of spacers in to see how many fit. Take it apart and put it back together with that many spacers.
They have a preload elastomer AFAIK - did anything drop off?
Kona TC - Memberbommer is spot on,
I have always removed the 10mm extractor cap cleaned behind it and smeared a bit of grease on the threads and crank bolt, refitted it tightening it up until snug. Then using an 8 mm Allen key undone the crank bolt anti-clockwise.
I did that the first time I took my diablous cranks off. The next ride the 10mm cap came loose, then the cranks came loose and damaged the splines. So don't grease the threads on the 10mm cap, use threadlock on them to ensure they stay tight!
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Karinofnine - MemberThat's interesting, I've put the crank back on - if I tighten it a lot, the cranks don't spin round as freely. What's going on? It's got a Hope BB - thought the cups of that were the bits that dictate pressure on the BB bearings?
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anotherdeadhero - MemberNo, the BB just sits there, the cranks should have some kind of bearing preload mechanism, but I'm not sure how the Raceface system works. Probably detailed in that Park tools instructional linked above.
The raceface cranks use soft plastic/hard rubber washers on the axle (non drive side end up against the crank arm) to adjust the preload on the bearings.
The instructions that came with my X Type cranks said to set the preload then tighten the cranks until the drive side crank bottoms out on the axle, i.e keep tightening until it stops.
If the BB is getting stiff before you have tightened the bolt fully then I would guess that you need to remove one or more of the washers from the axle (if they are dirty then they can look like part of the non drive side crank arm where it meets the axle) They are a bugger to prise loose once theyve been pushed on tight by tightening the cranks up. I've had most sucess with a very thin sharp knife or chisel tapped down between the washers to loosen them.
Saw a post on here a while ago where a Hope BB wore out fast and Hopes reply was that it had been over tensioned. IIRC Hope said the cranks should spin freely once fully tightened to avoid wearing the bearings out.
The raceface cranks use soft plastic/hard rubber washers on the axle (non drive side end up against the crank arm) to adjust the preload on the bearings.
To be clear, that's what I meant.. Not the BB cup spacers!!!
Andy,
forgot to add I wipe the grease off once the cranks are off - the grease is only there to to ease friction between the extractor cap and crank bolt 😳
As above - check out the [url= http://www.raceface.com/instructions/CRANKS/Atlas.AM.Crank.web.pdf ]instructions[/url] to help illustrate the various washers etc etc.
But, as you haven't actually changed any of the bits, I'd double check that the non-drive-side cranks is fully seated through the BB before messing with anything. Give it a hefty whack with a rubber mallet or similar. If it's not through properly it can bind up as described, and surprisingly the winding on of the drive side crank doesn't always pull it through and fully seat it.
And of course try and remember what washers came off and that they all went back on in the same place 😉