Thanks for the link. I just bought another Project Underground aluminum frame. Unfortunately I don’t think a 2.10 will fit on the rear. Last 3 frames I had to use 1.95 in the rear. I ran IRC Mythos 1.95 in the rear and 2.10 in front.
Not sure I’m going to even build this frame, and if I do it will be a wall hanger for display, and if I do I might try and squeeze a 2.10 on back. I’ve had 3 other of these frames and rode them all, and unfortunately all 3 cracked at the head tube. I have plenty of other bikes to ride, and I’m not in a hurry to build this one. They’re difficult to find, and besides, my wife still doesn’t know I bought it.