I’m not sure if this is a stupid question, but could you swap the lowers on a 26″ fork to a 27.5″ to run 650b ?
Maybe some internal spacers are required as well?

Which forks? Many fox are 27.5 compatible.

Fox 32 floats

just tried to pull part numbers on a few things on the service site, but 2014 stuff is not as detailed as it is for 2013 and prior year part numbers… but, based on 2014 spec, the A-C height on a 27.5″ fork is longer than 26″. Aprox 13mm for a 32 float. So, presumably the cartridge is also longer.
As the bushings will be the same ID, I’d imagine you could swap lowers but presumably you’d loose that 13mm in travel.
So, 150 might now = 137?

On a side note, a 2013 32 Talas FIT will take a 27.5″ wheel with a 2.4RQ mounted. Somewhere less than 5mm clearance though

Yes, no maybe, you might not need to 🙂

Cheers for the info. Sounds like its possible

The trail and offset are be different for 26 and 29er forks.

What are manufactures doing for 27.5? Are they using an in between offset or using the same one from 26 or 29?