Pneumatic tire manufacturing method

A method for manufacturing a motorcycle a pneumatic tire comprising a carcass extending from a tread portion through sidewall portions to bead cores in bead portions and a tread reinforcement layer disposed radially outward of the carcass in the tread portion, the method comprising:

• a tread reinforcement layer formation step of forming the tread reinforcement layer, wherein
• the tread reinforcement layer formation step comprises a winding step of winding a single continuous belt-like ply formed by covering one or more reinforcement cords with a topping rubber around an approximately cylindrical winding surface,
• the winding step comprises:
• a first winding step of winding the belt-like ply in a spiral manner from a first end portion located on one side in a tire axial direction to a second end portion located on the other side in the tire axial direction while separating side edges of the belt-like ply from each other in turn;
• and
• a second winding step of winding the belt-like ply in a spiral manner reversely with respect to the first winding step from the second end portion to the first end portion while separating the side edges of the belt-like ply from each other in turn to form a grid-shaped tread reinforcement layer having approximately diamond-shaped spaces surrounded by the belt-like ply, wherein the grid-shaped tread reinforcement layer, in a tire cross-sectional view, extends over the tread portion that protrudes radially outwardly in an arc shape manner such that a pair of tread edges forms a pair of axially outermost locations of the tire,
• wherein the winding step comprises a parallel winding step of winding the belt-like ply in parallel along a tire circumferential direction to form a parallel portion extending from one of the first end portion or the second end portion,
• wherein the parallel portion extends in less than 360 degrees around a tire axis, and
• wherein in the winding step, an end surface of a winding terminal end of the belt-like ply is in contact with an end surface of a winding start end of the belt-like, or the winding terminal end of the belt-like ply and the winding start end of the belt-like ply overlap with each other in a length of 10 mm or less in the tire circumferential direction.

A method for manufacturing a motorcycle a pneumatic tire comprising a carcass extending from a tread portion through sidewall portions to bead cores in bead portions and a tread reinforcement layer disposed radially outward of the carcass in the tread portion, the method comprising:

• a tread reinforcement layer formation step of forming the tread reinforcement layer, wherein
• the tread reinforcement layer formation step comprises a winding step of winding a single continuous belt-like ply formed by covering one or more reinforcement cords with a topping rubber around an approximately cylindrical winding surface,
• the winding step comprises:
• a first winding step of winding the belt-like ply in a spiral manner from a first end portion located on one side in a tire axial direction to a second end portion located on the other side in the tire axial direction while separating side edges of the belt-like ply from each other in turn;
• and
• a second winding step of winding the belt-like ply in a spiral manner reversely with respect to the first winding step from the second end portion to the first end portion while separating the side edges of the belt-like ply from each other in turn to form a grid-shaped tread reinforcement layer having approximately diamond-shaped spaces surrounded by the belt-like ply, wherein the grid-shaped tread reinforcement layer, in a tire cross-sectional view, extends over the tread portion that protrudes radially outwardly in an arc shape manner such that a pair of tread edges forms a pair of axially outermost locations of the tire,
• wherein the winding step comprises a parallel winding step of winding the belt-like ply in parallel along a tire circumferential direction to form a parallel portion extending from one of the first end portion or the second end portion,
• wherein the parallel portion extends in less than 360 degrees around a tire axis, and
• wherein widths of the approximately diamond-shaped spaces in the tire axial direction are in a range from 3 to 10 times larger than a width of the belt-like ply.