Current Projects chat and miscellany

You might as well ask for a complete recital of Graham's number.

Sugino 75's are ISO taper. dura ace bb will be JIS. The taper is only very slightly different. You can run ISO cranks on JIS tapers, and vice versa.

JIS BB spindles are slightly fatter than ISO spindles. So, if you were to fit 2 sets of identical ISO cranks, one on an ISO spindle and one on a JIS spindle, the cranks on the JIS spindle would sit a few mm further out from the BB shell.

From memory, sugino 75s run on a 110 ISO spindle (or is it 109?) to get 42mm chainline. Therefore a 107mm JIS BB might put you in the ball park.

However, as Sheldon brown pointed out (I think), a lot of companies really don't precision engineer the tapers in their cranks (even the expensive ones!), and he found massive discrepancies via the use of digital callipers with different pairs of seemingly identical cranks.

More people still vehemently oppose the use of JIS on ISO and vice versa. I have a set of 75s that have been used on JIS BBs for seemingly eternity (I bought them 2nd hand), and they seem to run ok. using a 107mm bb seems to be the easiest and cheapest option for getting an optimal chainline with 75s, unless you want to splash out on the phil BB with adjustable cups, or a centaur bb (if you can find one! Now that centaur cranks use the ultra torque system, i'd guess that square taper centaur bbs are going to be discontinued soon, if they haven't been already).

Hope this helps.

http://www.evanscycles.com/products/campagnolo/centaur-bottom-bracket-superlight-ec007776?query=centaur%20bottom%20bracket