Shimano BBUN-55 Bottom Bracket Question!?

rob w

Is anyone familiar with the Shimano BBUN-55 Bottom Bracket, im about to buy a 113mm spindle length version…..and want to know & cant seem to find out if the spindle is symettrical, or is one side longer than the other!

Thanks!

Alek

Haven't measured but AFAIK the spindle is symmetrical.

You can install any square taper BB with a 1-2mm spacer on the right side if you want to adjust the chainline a bit outwards.

aldark

spindles are not symmetric, google for square taper bb spindle length

Alek

aldark wrote: »

spindles are not symmetric, google for square taper bb spindle length

You are right - at least partially:

http://www.sheldonbrown.com/bbsize.html

But 113mm, 124mm and 136mm are actually symmetric

aldark

Knew I had this somewhere - measurements of shimano square taper bb's. Right factor measures from the inside of "lip".

Nominal Size Right Factor
68 x 107 20.5mm
68 x 110 20.5mm
68 x 113 22.75mm
68 x 115 23.75mm
68 x 118 25mm
68 x 122.5 28mm
68 x 127.5 30.5mm
70 x 107 19.5mm
70 x 110 19.5mm
70 x 113 22mm
70 x 115 22.25mm
70 x 118 24mm
73 x 107 18mm
73 x 110 18mm
73 x 113 20.25mm
73 x 118 22.5mm
73 x 122.2 25.25mm

rob w

Thanks for the replies lads, I had googled it to death, including looking at Sheldon Brown, but never noticed that table on it with dimensions!!!