83mm cranks in 73mm...
 

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[Closed] 83mm cranks in 73mm frame

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Will it work? Surely just some spacers on the BB should sort it


 
Posted : 29/09/2016 11:52 am
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Am I missing something here? I thought companies only made one length of axle in the case of hollow tech style cranks? So with the appropriate BB and spacers they will fit any width of shell?


 
Posted : 29/09/2016 11:57 am
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You could put an extra 5mm of spacers either side. but that leaves very little thread for your BB to thread into. Saint BBs have a long thread on the drive side, but the non drive side would be very sketchy

Spacer directly on the crank arm, maybe. You'll have a horrific chainline.


 
Posted : 29/09/2016 11:58 am
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mtbtomo - Member

Am I missing something here? I thought companies only made one length of axle in the case of hollow tech style cranks?

Nope, 83mm cranks have a wider axle


 
Posted : 29/09/2016 12:09 pm
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Yeah 68/73mm is the same length but 83mm is longer axle, not sure I'd want to space it out that much. If you have to then try and get something like a saint bb which has longer threaded interface than some.


 
Posted : 29/09/2016 12:31 pm
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Bump! Anyone actually done it? 5mm either side can't be too bad...


 
Posted : 30/09/2016 8:15 am
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I did this years ago when I was a poor student.
I ran the BB setup normally for 73mm, then added a 10mm spacer that sat flush with the crank spindle on the OUTSIDE of the BB (so between BB and crank) on the none driveside. I ended up with the same chainline drive side. I can't say I ever had an issue. Once you get used to the slightly off centre cranks, it's fine. I couldn't feel the difference after a few hours.


 
Posted : 30/09/2016 8:21 am
 maxb
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Depends on the crankset - I had this on my RaceFace Atlas (88mm) cranks and machined up some different thickness spacers to fit them in a 68mm shell - absolutely no problem. Threading does not come into it as the bearings are HTII threaded into the frame and the crank arm tightens onto the spindle the same. The spacers go on the spindle.


 
Posted : 30/09/2016 8:32 am
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It's RF cranks I'm looking at. I no longer have access to a machine shop, don't suppose you still have those spacers by any chance maxb?


 
Posted : 30/09/2016 8:43 am
 maxb
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Yes - yours for £39 delivered with a [b]free [/b]RF Atlas chainset below:

http://singletrackmag.com/forum/topic/race-face-atlas-dh-mtb-cranks-excellent-condition-39-posted-1


 
Posted : 30/09/2016 8:58 am
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Cheers max but red cranks would not suit my build at all


 
Posted : 30/09/2016 11:07 am
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Anyone know whether the spacer idea would work with Cinch cranks?


 
Posted : 01/10/2016 8:40 pm
 maxb
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Depends on the set up - with the Atlas cranks the inner 'band' or ring on the arm sits upon the bearing - if you make a spacer to the same dimensions as this then you can adapt them to fit different spacings.


 
Posted : 01/10/2016 9:50 pm

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