Railway tire

The wheel centre, usually already mounted on the axle, is lowered into the tire which is flange side up.

This shoulder was severely limited in size as it had to pass over the wheel centre for assembly.

The utilisation of traditional freight wagons was often so low that tires never needed renewal, so it was cheaper to fit a one-piece ("monoblock") wheel.

Modern flow-line repair lines are disrupted by the inspection of the wheel centre once the tire is removed, possibly generating extra rectification work, and the need to make each tire fit its allocated wheel centre.

Because the brake blocks apply directly on the tire, it is heated up, relaxing the interference fit.

In rare instances the rotation could be so severe as to wear the retaining ring down till it breaks, which could result in derailment.