Abstract: A method of fitting a tire P and a removable tread support S on a one-piece wheel rim J, rim comprising a first rim seat, inclined outwards, and the tire P comprises a first bead and a second bead to be mounted respectively on the first and second rim seats, in which, before completion of fitting the support S on a rim bearing surface of the rim, the first bead is gripped at a given point and is moved radially outwards to radially separate this point on the first bead from the support S. The fitting of the support S on the rim bearing surface continues and the bead is released after completion of the fitting of the support S.