So did you just use 650b wheels and fork, and everything fit? Rides ok?
I'm using 27.5 wheels on a 26er frame and 26er fork. The front tire (Maxxiss Ardent 2.2) did not have enough clearance in the frame or fork. I'm currently using Racing Ralphs 2.2 on the front and rear. I personally don't like the tire for the front. I'm going to see what my other options are.
The bike rides perfect. I'm still trying to get the suspension setup correctly. I had to lower the stem a bit to lower the front end. The front end broke loose on steep climbs. I'm going to try it with 26" wheels and see what wheel size I like best on this frame.