I can't Google any definitive information on this so here goes:

I understand that a BB86 bottom bracket fits a wider shell. My bike is 86.5. The specs for FC-6700 (130BCD 39/52) say 68/70mm shell width. I'm guessing this means the drive side spindle isn't long enough (???). If I want to replace my Ultegra crankset, what do I buy for a BB86?

Thanks!
James

In BB86, the cups are internal, where as on 68mm and 70mm shells they are external.

You can't change the spindle length on the newer 2 piece cranksets, so there's no need to calculate spindle length.


here's a picture of a BB86 bottom bracket, and you might notice they have lips at the edges.
https://www.competitivecyclist.com/pr...6758.19.1.html

here's a picture of a standard 68mm or 70mm external cup BB, and you can see that the lips are much thicker.
https://www.competitivecyclist.com/pr...239.314.0.html

Ah, that makes sense. So just a stock, 68/70 spindle works fine with an 86.5 BB shell width? That's a relief, I thought I would have to hunt for a OEM part...

Thanks for the reply.