TREAD RUBBER FORMING METHOD AND TREAD RUBBER FORMING DEVICE

A tread rubber forming method includes: a first step of forming a base layer; a second step of forming a first intermediate layer on a portion of an outer circumferential surface of the base layer; a third step of winding and superposing a third rubber strip on an outer circumferential surface of the first intermediate layer, to form a first cap layer; a fourth step of winding an electrically-conductive fourth rubber strip from a position of contact with the base layer to an outer circumferential surface of the first cap layer, to form an electrically-conductive layer; and a fifth step of forming a second cap layer on an outer side in a radial direction of the base layer such that a portion of the electrically-conductive layer is exposed to an outer side in the radial direction of the tread rubber.