Originally Posted by
Tourist in MSN
My Thorn Nomad Mk II, I usually use that with 57mm wide tires, but I did try some 40mm wide tires on it to see how it would handle, handled just fine. The width difference was 17mm.
You are looking at tire sizes that range over 20mm, not much greater than the 17mm range I cited. My point is that you might want to get the 650b wheels. See how 55mm and how 35mm tires work on those wheels. You might decide that a second wheel set is not needed.
Oh, I would try that first before buying a second wheel set but I would be concerned that the ground to pedal spindle measurement would change a lot too. That said, I would indeed try it first.