The object of the invention is a rotationally symmetric vehicle wheel rim (26) designed for the mounting of a tyre, comprising a first seat (30) intended to be positioned towards the inside of the vehicle and a second seat (32), the first seat (30) being extended axially towards the second seat (32) by a safety hump (40) and comprising a frustoconical bottom (34) which coincides locally with a cone of revolution (46) open towards the second seat (32) and coaxial with the rim (26), and an inner edge (36) which extends the bottom of the first seat (30) towards the second seat (32), such that on the hump side the inner edge (36) of the first seat (30) is tangential to a cone of revolution (48) coaxial with the rim (26) and open towards the second seat (32, with an apex angle larger than 103°.