A method for manufacturing a motorcycle tire comprises: building a raw tire main body, building a breaker, sticking the breaker, and building a band. The building of the breaker comprises: moving two cylindrical support rings to operating positions, swelling the raw tire main body to have its crown portion protruding from the support rings through a gap therebetween, and winding a breaker ply material on the support rings to form a cylindrical breaker ply whose inner surface is adhered to the raw tire main body. The sticking of the breaker comprises: expanding a profiled deck to swell the raw tire main body into a second swollen state, and turning down both edge portions of the breaker while being supported by the profiled deck. The building of the band comprises: spirally winding a tape on the curved breaker ply while being supported by the profiled deck.

Disclosed are an adjusting method and an adjusting apparatus for an axial dimension of a middle drum assembly, and a building drum. The adjusting apparatus for the axial dimension of the middle drum assembly includes a first middle drum block, a second middle drum block, and an intermediate middle drum block located between the first middle drum block and the second middle drum block. The adjusting method includes: moving at least one of the first middle drum block and the second middle drum block in a direction of approaching each other, and the first middle drum block, the second middle drum block and the intermediate middle drum block cross and retract with each other, so as to shorten a length of the middle drum assembly; moving at least one of the first middle drum block and the second middle drum block in a direction away from each other, and the first middle drum block, the second middle drum block and the intermediate middle drum block cross and extend with each other, so as to increase the length of the middle drum assembly. The present application solves the problem in the related art that the production efficiency is reduced due to the frequent replacement of a tooth block.

A process for building tyres provides for building a carcass sleeve around a forming drum having an application diameter and two lateral half-portions axially moveable relative to each other. The carcass sleeve comprises at least one carcass ply coaxially engaged around each of the axially opposite end flaps thereof to an annular anchoring structure defining a fitting diameter smaller than the application diameter. The building of the carcass sleeve comprises: applying and stopping a leading end of a semi-finished product in form of continuous strip cut to size against a continuous surface of the forming drum; winding the semi-finished product in form of continuous strip cut to size circumferentially around the forming drum; joining a trailing end of the semi-finished product to the leading end at said continuous surface. The continuous surface is extended only partly around the forming drum. The semi-finished product, except for the leading end and the trailing end, is laid against a discontinuous circumferential surface of the forming drum adjacent to the continuous surface and belonging to the two lateral half-portions.

Disclosed is a power transmission device of a green tire forming drum apparatus. The green tire forming drum apparatus includes a carcass drum shaft, left and right forming drums mounted to the carcass drum shaft in a laterally symmetrical manner and being movable laterally in an axial direction of the carcass drum shaft, finger mounting supports for moving left and right turn-up fingers, respectively mounted to the left and right forming drums, up and down, and a driving unit for supplying power required for rotation& and later& movement of the forming drums and up/down movement of the turn-up fingers. Power generated by a lower servomotor of the driving unit is transmitted to the forming drums via pull/push plates connected to a ball screw, and power generated by an upper servomotor of the driving unit is transmitted to the turn-up fingers via pull/push plates connected to another bail screw.