A process for manufacturing a tyre includes: providing a first plurality of strip-like elements, each substantially having a first effective width; providing at least a second plurality of strip-like elements, each substantially having a second effective width; arranging the strip-like elements of the first plurality and of the second plurality on a support by approaching side edge portions thereof to one another, so as to form at least one reinforcing component of the tyre on the support; wherein the first effective width is different from the second effective width.