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Rotor BSA 30 Bottom Bracket

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Rotor BSA 30 Bottom Bracket

Postby larry_ck » Sat Jan 19, 2013 8:29 pm

I stumbled across this the other day http://www.rotorbike.com/products/road/ ... a-frame_38 and it has got me thinking .. I wonder has anybody tried this with another manufacturers BB30 cranks .. would it work or not? While I have found information on the rotor site about it only being compatable with rotor cranks, at the moment I haven't got the resources to pull the trigger as an experiment so I'm drawing on the collective knowledge of the forum .. Any thoughts?
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Re: Rotor BSA 30 Bottom Bracket

Postby Ypsylon » Wed Jan 30, 2013 11:31 am

I really don't see how it would not work with any bb30 crank if the rotor cranks work with regular bb30 bbs, which I believe they do.

Then again, I don't get how the Rotor bb30 for bsa could possibly fit there, even for rotor cranks.

This is still not the first hand info you were looking for, and I am definetly not the be all end all bb standard guru, so it would still be an experiment.
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Re: Rotor BSA 30 Bottom Bracket

Postby larry_ck » Wed Jan 30, 2013 11:48 pm

Thanks for your thoughts. I've been thinking a bit more on this myself and come to the following concusion .. BB30 is a 68 shell width so putting the bearings external on a standard BSA shell of 68 means they must be around 86 width. So Rotor must be doing something different with the crank spindle length / crank arms to make it work. Running anything else a) would not fit due to spindle length b) if it was a hollowgram type system with interchangable spindle then the result would likely mess with the chain line and Q factor .. Please step in if anyone has any other thoughts.
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Re: Rotor BSA 30 Bottom Bracket

Postby Ypsylon » Thu Jan 31, 2013 12:59 pm

The spindle length is what's confusing me as well.

My best guess is that the Rotor 3D+ crank they specifically name with the BB has a longer spindle. Mabye that has something to do with BBright Cervélo standard. They could just use spacers on regular BB30s then, I guess.

To be honest, when it comes to BBs I just assume something will not fit and just do the research for a given combo.

Even if the crank will work with the bb that goes into the frame, the crank might still interfere with the frame. That's why I never even bothered to at least try and stay on top of bbs and cranks, because it gives you a mean headache and you still can't be sure something works until you have it in front of you.
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