Bicycle Tutor

I am going to replace BB on my Rockhopper, the code on the spindle reads 3P, meaning that it is 119mm. Being that each side is different in length, would a BB from World Industries in 121mm be correct symmetrical length? Any other suggestions on replacing with a sealed bearing BB would be much obliged.
Thanx Wildernest69

According to Sheldon Brown, 3P is a 68x119 spindle and the symmetrical equivalent would be a 122mm spindle (http://www.sheldonbrown.com/bbsize.html)
Unless your chainrings sit very close to the frame, 1 or 2 mm either way probably doesn't make a big difference. But make sure you get a BB made for a 68mm wide BB shell or it won't fit your frame well. I can't find any info on World Industries' BB. Also make sure you get a square taper spindle if that is what your cranks have.

They may be a different lengths to account for the chainrings on one side.
Have a look at the cranks and see if they are equidistant from the chainstays.
(I generally work on the principle to use the narrowist BB that doesn't allow the inner chainring to catch the frame.)