Its tricky to fit a double chainset on a 29+ bike and even harder to avoid tyre/chain rub when you do.
I have been experimenting with the “Rudy Fat” and it can be easily achieved with a standard 2 x 10 Shimano set up with no alterations just with the addition of a KCNC PF30 adapter and running the 2.5mm spacer on the drive side instead of the non drive side.
As you can see from the photos there is no chain rub at all even in the small front chain ring and the largest sprocket on the cassette.
We can supply the KCNC PF30 converter when you buy the frame. Please email us for details.