Custom Rob English MTB

I'm thinking no more than 4", especially with some of the great tread choice out now in the sub 4" range..
If I use the fatbike base with 1OOmm BB it means I can run any tyre size including the Krampus platform, as the stays on that are only about 3mm longer than my current twenty niner.
Longer stays have the benefit of more stability when the bike is loaded, and more comfort on a hardtail.

I want to be able to use the bike as my regular twenty niner, but also be able to run it fat front, full fat, Krampus style, or any possible combo.

I reckon if anyone can make this work, Rob can, as he's never one to shy away from some problem solving.

I seem to remember you mentioning a eccentric BB. How would that work in a 100mm BB shell?

Custom?