A tire comprising a tread having a block pattern, wherein the block pattern includes: a sea; a plurality of blocks, each block rising from the sea and having a land; and a plurality of tie bars, each tie bar rising from the sea, a plurality of block pairs (28a, 28b) are formed in the block pattern, each block pair (28a, 28b) including two adjacent ones of the plurality of blocks, the block pairs (28a, 28b) include a plurality of linked block pairs, each linked block pair includes two of the plurality of blocks (28a, 28b) and one of the plurality of tie bars, the tie bar of the linked block pair being interposed between the two blocks (28a, 28b) and linking the two blocks (28a, 28b) together, and the tie bar of the linked block pair has a toe end having a height equal to or smaller than a height (Hb) of the blocks (28a, 28b) and a heel end having a height smaller than the height of the toe end, wherein during forward rotation of the tire, the heel end makes contact with the ground first and then the toe end makes contact with the ground, characterized in that the tire is a motorcycle tire for running on rough terrain, and the tread includes a crown zone (Zc) located in a center of the tread in an axial direction of the tire; a pair of middle zones (Zm), each middle zone (Zm) being located outward of the crown zone (Zc) in the axial direction; and a pair of shoulder zones (Zs), one of the shoulder zones (Zs) being located outward of one of the middle zones (Zm) in the axial direction, the other of the shoulder zones (Zs) being located outward of the other of the middle zones (Zm) in the axial direction, wherein a ratio N1/N in the crown zone (Zc) is 0.10 or more, wherein N1 represents the number of the linked block pairs in which the height H2 of the toe end is greater than the height H1 of the heel end and N represents the number of all the block pairs. the block pattern includes: a sea; a plurality of blocks, each block rising from the sea and having a land; and a plurality of tie bars, each tie bar rising from the sea, a plurality of block pairs (28a, 28b) are formed in the block pattern, each block pair (28a, 28b) including two adjacent ones of the plurality of blocks, the block pairs (28a, 28b) include a plurality of linked block pairs, each linked block pair includes two of the plurality of blocks (28a, 28b) and one of the plurality of tie bars, the tie bar of the linked block pair being interposed between the two blocks (28a, 28b) and linking the two blocks (28a, 28b) together, and the tie bar of the linked block pair has a toe end having a height equal to or smaller than a height (Hb) of the blocks (28a, 28b) and a heel end having a height smaller than the height of the toe end, wherein during forward rotation of the tire, the heel end makes contact with the ground first and then the toe end makes contact with the ground, characterized in that the tire is a motorcycle tire for running on rough terrain, and the tread includes a crown zone (Zc) located in a center of the tread in an axial direction of the tire; a pair of middle zones (Zm), each middle zone (Zm) being located outward of the crown zone (Zc) in the axial direction; and a pair of shoulder zones (Zs), one of the shoulder zones (Zs) being located outward of one of the middle zones (Zm) in the axial direction, the other of the shoulder zones (Zs) being located outward of the other of the middle zones (Zm) in the axial direction, wherein a ratio N1/N in the crown zone (Zc) is 0.10 or more, wherein N1 represents the number of the linked block pairs in which the height H2 of the toe end is greater than the height H1 of the heel end and N represents the number of all the block pairs.