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Hi,
I'm building up a On one 456 summer raw, the BB that i have from my old bike is 68 by 113, the 68 part is fine, but the axle is to short for a shimano 3 chain ring crank as the inner and outer chainrings touch the frame.
Any one with a On one 456 know what BB to use with a 3 chainring crank?
Cheers
sounds like you have the wrong width BB in the first place.
BB axle widths are determined by the chainset and not the frame.
well the BB and crank came off the old bike which was a single pivot full suser so they were fine together on that one, however it's now gone onto a hardtail, and the frame has a conventional chainstay which is now being hit by the crank, which was not a problem on the old one because it had no chainstay as such!
so yes, i have the wrong BB width, but i think the BB width is determnined by frame rather than chainset.
Still need to know the magic number though!
Now its just a guess, but HTTP404 might be right, maybe it is the wrong BB for the chainset but it wasnt highlighted on your old bike as it didnt have a conventional chainstay, it wouldnt be out enough to really ruin the shifting and running so it didnt show up untill now?
conventional mtb frames run a 47.5mm chainline.
which would eliminate frame dependency for BB axle widths.
checkout sheldon brown's website.
on ones run a 51mm chain line, however i've just setup my friends 456 with a sq taper BB which is 68x113 and its fine.
what type of bb is this you're fitting? ISIS or Sq taper? is is possible the tapers are worn on your cranks if the latter?
Bottom Brackets need to be matched to Cranksets and the right combination should work on almost any frame, some that have extra fat seat tubes or other madness may need something frigged.
[url= http://www.sheldonbrown.com/bbsize.html ]Sheldon Brown's BB Size Guide[/url]
I used to run a 113 but I think the stays have been tweaked since then. I now rnu 118 to get a better chainline with a double'n'bash set up.
I run mine with a 68 x 118 with my XT hollowtech 1 crankset and its perfect