When you fit a

[Standish]

New chainset,and you've got the right size bb, should the ends of the cranks be the same distance from the chainstays. Looking at all my bikes road and mtb the non drive side is closer by a few mm, is this ok.

 

[marc two tone]

distance

sounds about right. quite normal.

just had a look a 3 examples and all seem a few mil closer on the crank arm side.

ok mate.

 

[jimo746]

The non-drive side? yes I would think so, as long as it's not contacting the frame! It's much more important on the drive side though to get the right chainline.

 

[FluffyChicken]

If it bothers you, you might be able to fix it and even it out if you buy the next size bottom bracket up.
e.g. 107mm then buy the 110mm will push the none drive side out by ~3mm (e.g. 110 to 113 pushes the drive side out 3mm)
Not all 'size ups' work though.

 

[Martin]

If it bothers you, you might be able to fix it and even it out if you buy the next size bottom bracket up.
e.g. 107mm then buy the 110mm will push the none drive side out by ~3mm (e.g. 110 to 113 pushes the drive side out 3mm)
Not all 'size ups' work though.

Are you sure, going from 110-113 then both sides go 1,5mm each way iirc? So that distance difference cant be cleared, only if the driveside was further away then you can mount spacer between frame and bb.

:?

 

[Standish]

The old bb was a raceface 107 x 68 -73 so i could adjust it to
be equal on both sides, but shimano un 54 107 x 68 has a shoulder, so
just screws up to the bb shell. I'll Probably try a 110mm, thanks for your
help chaps.

 

[FluffyChicken]

If it bothers you, you might be able to fix it and even it out if you buy the next size bottom bracket up.
e.g. 107mm then buy the 110mm will push the none drive side out by ~3mm (e.g. 110 to 113 pushes the drive side out 3mm)
Not all 'size ups' work though.

Are you sure, going from 110-113 then both sides go 1,5mm each way iirc? So that distance difference cant be cleared, only if the driveside was further away then you can mount spacer between frame and bb.

:?

In Shimano world. No.
A search might not pick it up but.

107 to 113 both sides increase evenly to give the 47.5 and 50mm chainlines
6/2 = 2.5 (yes I know )

But the 110 doesn't follow that, it was an infill length that came after, I can only assume to increase none drive side length and allows alteration of chainline too, if you use spacer on the drive side (assuming UNxx style).
It adds the length to the none drive side and leaves the chainline at 47.5

I didn't know this until a short wile back and had always assumed it would add evenly and so lining up with the chainline for the middleband (31. front mech.

But I suppose being .5mm further out doesn't really matter in the scheme of square taper chainline tollerance, but then 1mm further out for the 34.9 band doesn't really.