Chain rings foul the chain stay.

fluroforks

Retro Guru
On fitting a pair Middleburn cranks (not sure which model) to an RC200 I find that the chain rings foul the chain stay. I was swapping them from a pair of XT m737 cranks to the middleburns. The XT's are a 94mm bcd and the middleburns are 110mm with a flat spider.

What do I need to do to correct this?
 
Thats alright,

I thought someone might suggest a different spider which could be hard to source.

Out of interest do you have any recommendations for BB's? Ive just fitted a UN53 to another bike and its creaking after 500 miles.
 
fluroforks":14r68mrs said:
Out of interest do you have any recommendations for BB's? Ive just fitted a UN53 to another bike and its creaking after 500 miles.

Sure it's the BB and not the crank just a tiny bit loose on the taper?

I echo what Ian said, and use the best Shimano BB I can get.
 
Ill have a look at that later, I hadn't really thought about the creaking but wondered what BB's you guys like anyway.

Back to the subject, i've just measured the BB im fitting the middleburns to only to find its already a 113mm shaft but its 5mm shorter on the drive side than the other. Does that mean its been fitted a' about t'?
 
No, they're all like that...

...plenty of Middleburn owners on here; someone will post the solution you're after before too long :cool:
 
fluroforks":3kuvjy0s said:
Ill have a look at that later, I hadn't really thought about the creaking but wondered what BB's you guys like anyway.

Back to the subject, i've just measured the BB im fitting the middleburns to only to find its already a 113mm shaft but its 5mm shorter on the drive side than the other. Does that mean its been fitted a' about t'?
Have you got the right shell size? There's 5mm difference there.
 
Sadly its a 68mm BB frame otherwise that would make perfect sense.

There is a 10mm difference between the inner face of the MB and the XT cranks. The BB axle in there is actually 110mm since I measured it with something better than a tape. If I fit a BB 10 or 12mm longer is the extra mm added to the drive side or to the overall length of the shaft?

(Does that make sense or am I off on one?)
 

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