The hump

The anti-debeading edge (also called hump) is an embossed edge inside the dropwell that keeps the bead in place. When the inflation pressure isn’t sufficient, the bead could run through or slip in the dropwell causing the sudden collapse of the tyre resulting in a loss of control of the vehicle: this is the so-called debeading. An anti-debeading edge (or hump) is needed specifically to avoid that such such events will happen, by not allowing the bead to slip over the dropwell even when the inflation pressure is low or none.

In case of a puncture on a tyre with tube (tube type) the loss of pressure is almost istant and, in the absence of Hump, the tyre could suffer a sudden beading with dangerous consequences on the vehicle balance. With a tubeless tyre the loss of pressure is usually slower and gives enough time to the rider to stop, but without an anti-debeading rim is not recommended to keep riding because when the air pressure becomes very low, it is possible that the beading will accur with a consequent deflation of the tyre.

Even though in case of puncturing a tubeless tyre will reduce the risk of a sudden deflation, the presence of a anti-debeading profile is always important.

cerchio senza e con hump a confronto