I'm interested in using a front wheel Magic Pie. Does anyone know if it will work with a fork that is made for a 20mm thru axle? Is there some kind of adapter needed?
I don't know of any adapter and I would probably stay clear of anything that isnt a certain. The torque applied by an MP on an adapted anchor point like Duane has said will need a good torque arm and I would be concerned about doing such a thing to front forks.
The MP or the ones I have seen have a flat edge on the two sides of the axle that help axle hold strong in the droputs. In essence the GM axles are 10mm
y and 20mm
x so what ever you use will have to be a sleeve that fits onto the fork to narrow the dropout still sounds if'y.
Maybe you could sit the axle in the fork on the flat edge of the axel. With some careful filing of the fork dropout you can make is flat so the flat axle edge and fork dropout seat is flush, then rig up an awesome torque arm to take the spin.