A motorcycle tire pair comprising a front tire and a rear tire, wherein each of the front tire and the rear tire includes a pair of beads, a carcass extending on and between a first bead and a second bead being the pair of beads, a band located radially outward of the carcass, and a tread located radially outward of the band, the carcass includes a large number of carcass cords aligned with each other, each of the carcass cords being inclined relative to an equator plane (ELf), the band includes a band cord extending substantially in a circumferential direction, the tread has a tread surface that comes into contact with a road surface, in a meridian cross-section, a contour line (TLf) of the tread surface has a portion divided in a length ratio of 1:2:1 from an equator (Ef) to an end (Fe) of the tread surface, and is thus divided into five parts, wherein the tire equator (Ef) is defined as the point of intersection of the tread surface and the equator plane (ELf,) and the end (Fe) of the tread surface is defined as an axially outer end of the tire, the five parts are a center part (CLf) including the equator (Ef), a pair of middle parts (MLf) connected to the center part (CLf), and a pair of shoulder parts (SLf) connected to the middle parts (MLf), an arc that passes through the equator (Ef) and both ends of the center part (CLf) is a first arc, an arc that passes through inner and outer ends of the middle part (MLf) and a center of the middle part (MLf) is a second arc, an arc that passes through inner and outer ends of the shoulder part (SLf) and a center of the shoulder part (SLf) is a third arc, a ratio (R1f/R1r) of a radius R1f of the first arc of the front tire to a radius R1r of the first arc of the rear tire is a center arc index (Ac), a ratio (R2f/R2r) of a radius R2f of the second arc of the front tire to a radius R2r of the second arc of the rear tire is a middle arc index (Am), a ratio (R3f/R3r) of a radius R3f of the third arc of the front tire to a radius R3r of the third arc of the rear tire is a shoulder arc index (As), characterized in that the middle arc index (Am) is greater than or equal to the center arc index (Ac), and the shoulder arc index (As) is smaller than the center arc index (Ac). each of the front tire and the rear tire includes a pair of beads, a carcass extending on and between a first bead and a second bead being the pair of beads, a band located radially outward of the carcass, and a tread located radially outward of the band, the carcass includes a large number of carcass cords aligned with each other, each of the carcass cords being inclined relative to an equator plane (ELf), the band includes a band cord extending substantially in a circumferential direction, the tread has a tread surface that comes into contact with a road surface, in a meridian cross-section, a contour line (TLf) of the tread surface has a portion divided in a length ratio of 1:2:1 from an equator (Ef) to an end (Fe) of the tread surface, and is thus divided into five parts, wherein the tire equator (Ef) is defined as the point of intersection of the tread surface and the equator plane (ELf,) and the end (Fe) of the tread surface is defined as an axially outer end of the tire, the five parts are a center part (CLf) including the equator (Ef), a pair of middle parts (MLf) connected to the center part (CLf), and a pair of shoulder parts (SLf) connected to the middle parts (MLf), an arc that passes through the equator (Ef) and both ends of the center part (CLf) is a first arc, an arc that passes through inner and outer ends of the middle part (MLf) and a center of the middle part (MLf) is a second arc, an arc that passes through inner and outer ends of the shoulder part (SLf) and a center of the shoulder part (SLf) is a third arc, a ratio (R1f/R1r) of a radius R1f of the first arc of the front tire to a radius R1r of the first arc of the rear tire is a center arc index (Ac), a ratio (R2f/R2r) of a radius R2f of the second arc of the front tire to a radius R2r of the second arc of the rear tire is a middle arc index (Am), a ratio (R3f/R3r) of a radius R3f of the third arc of the front tire to a radius R3r of the third arc of the rear tire is a shoulder arc index (As), characterized in that the middle arc index (Am) is greater than or equal to the center arc index (Ac), and the shoulder arc index (As) is smaller than the center arc index (Ac).