MTB Bottom Bracket ...
 

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[Closed] MTB Bottom Bracket on a Road Bike

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Does anyone know what a road bike HTII bottom bracket measures total width? - ie the full width when the cups are in place on the bike?

I need to install some cranks first thing and all I have is a XT MTB BB
The cups will obviously screw in and I can just ditch the inner sleeve or cut it down a bit, reading elsewhere, someone is saying the the road cups are 1mm narrower [10mm Vs 11mm] so in theory a 1mm spacer each side should bring it all where it needs to be.
Can anyone save me the trial and error time in the morning?

TIA


 
Posted : 15/08/2012 6:13 pm
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the meausrement of the cups is ever so slightly larger on mtb compared to that of road.


 
Posted : 15/08/2012 6:18 pm
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a 1mm spacer on your xt cups would make them 3mm too wide


 
Posted : 15/08/2012 6:19 pm
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So you're saying the MTB cups are 0.5mm wider on each side?


 
Posted : 15/08/2012 6:21 pm
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sorry, 1mm wider per cup plus 2x 1mm spacers would make it 4mm too wide.


 
Posted : 15/08/2012 6:22 pm
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Bugger!!!

you advice is the total opposite of this I found, now confused 😐

http://www.bikeradar.com/forums/viewtopic.php?p=16135141


 
Posted : 15/08/2012 6:24 pm
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i was under the impression that road cups where slightly wider.


 
Posted : 15/08/2012 6:26 pm
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I guess some 'suck it and see' time will be required after all

thanks for your help guys


 
Posted : 15/08/2012 6:30 pm
 wool
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Running Mtb bb on shimano compact cranks no problem just try it


 
Posted : 15/08/2012 6:33 pm
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Road cups are definitely wider, i've measured them just to satisfy my curiosity(think it was 1.5mm per cup in my fading memory).


 
Posted : 15/08/2012 8:38 pm
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Cheers for that - I'll stick a spacer either side and see how it is


 
Posted : 15/08/2012 8:42 pm
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Just for the record and in case anyone else needs the info at some time

English thread Shimano road BB cups are 90mm wide when installed without any spacers in a road frame and the MTB cups are 88mm

I've just left it at 88mm and see how it goes


 
Posted : 16/08/2012 10:10 am
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I've done it a few times with no problems on our bikes over the years. Although at the moment I'm running a Truvativ MTB crankset on my road bike as needed easier gears for a weeks riding in the Alps and couldn't afford a compact chainset and the original one was massive.


 
Posted : 16/08/2012 10:37 am

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