Just curious.. I did it briefly on a 650b bike with a 26″ fork but quickly bought some 650b forks – interested if anyone rides it with a 29er fork?

29er forks and 27.5 wheel or 29 and 29? Same travel as the 27.5 fork should be or less?

This is a 29/27.5 design:

Foes Mixer Trail

I think people are more likely to stick a 650b rear wheel in a 29er frame.

What you’re suggesting wouldn’t do anything useful to the gemoetry that I can see.