A method for manufacturing (S) a subassembly (3) for a tire (4) comprising the following substeps: providing an assembly comprising a supporting structure (14) comprising supporting filamentary elements linking a first structure (10) of filamentary elements and a second structure (12) of filamentary elements, aligning (S1) the first structure (10) and the second structure (12), securely fixing (S4) the first structure (10) onto the second structure (12) using a securing element (18), and cutting (S5) the assembly (1) along the securing element (18) so as to separate said securing element (18) from the rest of the assembly (1) and to obtain at least one subassembly (3) without securing element (18).