Captain Crunch

What 's the difference between these two BB's and what are the benefits of each if any over the other? I cannot seem to find much info on either anywhere.

Thanks

khuon

I'm not sure what the exact differences are between ISIS and Octalink but the differences between ISIS and Shimano splined XT/LX and Shimano splined XTR (note that XT/LX and XTR are also different from each other I believe... XT/LX might be Octalink) is that ISIS uses 10 splines that are set deeper along the spindle than Shimano's 8-spline design which don't run as far along the spindle. There are also differences in the width and curvature-depth (ISIS grooves are deeper but narrower) of the splines too as well as the thickness of the spindle. I'm not certain if there's a diameter difference however it's more than likely there is.

The ISIS Drive webpage has all the specs of course but I don't know of a webpage that details Shimano's spline specs of which there are many versions.

Sheldon Brown's webpage about BB sizes details more important fitting information such as chainline positions and spindle-lengths.