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BB/axle diameter and length?

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Old 10-03-16 | 06:43 AM
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BB/axle diameter and length?

Hello!

Basically, I'm looking convert my CX-bike to 1x10 as well as upgrade it with a powermeter. I want to do this by switching to a Rotor powermeter crankset and mount a single chainring on it. So far so good?

My bike has a 68mm wide bottom bracket "casing" (forgive my terminology!), as in, the width of the frame at the bottom bracket. The BB itself is currently a "FSA Ms185 Megaexo 68mm/24´mm", English thread.

The Rotor crankset has a 30mm axle. The Rotor crankset states "The "UBB System" is not a standard. It's all standards because it allows the installation of almost any 24 or 30mm Rotor axle crank on your bike, regardless of its BB type. " - but it does not specify how so?
Rotor also make "Rotor BSA30 Steel Bottom Bracket Cups BSA-68-30" (the crankset specifies it is not supplied with BB cups, I take it these are what I need?) - which is described as "The Rotor BSA30 bottom bracket cups allow the installation of 3D+ cranks with integrated 30mm axle in classic BSA threaded frames."

Long question short, what do I need to do to fit a Rotor Power LT with a 30mm axle on my bike with a 24mm BB? Can I just swap my BB out to the BB Cups mentioned above? Effectively increasing the BB diameter? Am I missing something?

Any help greatly appreciated.
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Old 10-03-16 | 03:06 PM
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New Bearings in the frame , if the spindle is 30 it wont fit in a 24mm hole will it?
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