A band spring arranged straddling a brake disc to apply an elastic action on a brake pad to bias the brake pad away from the brake disc is provided. The brake pad has a backing plate supporting friction material and having a plate edge forming at least one thrust portion and at least one striker portion. The band spring has a band-shaped spring body and three portions, at least two of which mutually distinct, namely a first coupling portion coupling the band spring to a caliper body, a second thrust portion applying an elastic action on the at least one thrust portion and a third abutment portion forming a support that prevents sliding of the second thrust portion when the band spring is subject to external actions, the third abutment portion, when abutting against the striker portion being biased by a peak or buckling load, avoiding that the band spring permanently couples with the brake pad.