A two-piece tire assembly 10 with a removable tread belt 12 for installing about the circumference of a tire carcass 14 is provided. The two-piece tire assembly 10 includes a tread belt 12 has a belt structure 90 having two or more belt layers 100, 110, 120, 130 each layer having one or more belts. The tread belt 12 has a radially inner surface 70 having one or more protruding circumferential ribs 72 or grooves 74 that fit into complementary grooves 18 or ribs 19 on an outer crown surface of the tire carcass 14. The tread belt 12 has a maximum axial belt width W at a radially inner surface. The carcass 14 has a maximum section width SW and ply line 20 having a maximum width P wherein W≦0.95P, BW≦5 0.85P and P