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Old 06-07-11, 02:33 PM   #1
tanguy frame
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Bottom Bracket and Crank Replacement - Special Circumstances

I want to convert to a compact crank. I have a steel frame with a 68mm bottom bracket width, but it is tapped for italian threads. Italian bottom brackets are sized for 70mm bottom bracket shells. Is it possible to place a spacer between the cups and the shell to take up the 2mm? Is each brand specific, or are there general guidelines? I haven't selected the hardware yet, the chain and cassette and derraileur are campy 10 speed, but I'm looking for a budget solution.

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Old 06-07-11, 02:53 PM   #2
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There are some BB without a shoulder to seat against, like, Phil wood ..

its not like Shimano's square taper types,
they would have a shoulder to tighten against.
Budget suggests a square taper , and a 110 bcd crankset,
to use 34 and larger chainrings.

if using an external BB of new stuff, it may not be critical

never owned one , maybe 2 _1mm shim spacers 1 for each side,
rather than 1_ 2mm
on the right. get all 3 and see..

Last edited by fietsbob; 06-07-11 at 02:57 PM.
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Old 06-07-11, 06:19 PM   #3
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Yes, it'll be fine assuming we are talking about external BB's. You can use the plastic ones that come on MTB external BB's, though I find they compress. I just took one to a machine shop and got me to machine me a couple in Al in different width's 0.5mm, 1mm, 2mm etc.
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Old 06-07-11, 06:23 PM   #4
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the spacer that goes behind a 10 spd shimano cassette should work. get 2 they are 1mm
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Old 06-07-11, 06:56 PM   #5
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Or...use Italian thread cups and an english 68mm spindle. Lots of both around on the C&V thread.
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