The hub centric ring (also known as Centre Bore Locators) is a device used with the wheels and are installed between the car wheel hub and the wheel. The purpose of the hub centric ring is to fill the empty space between the wheel hub and the centre bore of the wheel. Centric rings are usually made of durable industrial plastic. Centric rings are also made of aluminum.
What are hub centric rings needed for? Hub centric rings are needed when the hub hole (the centre bore) on the wheel is larger than the wheel hub of the car. The wheel manufacturers deliberately make the hub ring as large as possible for the wheel, taking in to consideration the hub hole, to allow the same wheels to be sold for the various different models of car using hub centric rings.
Centric rings are usually needed only for after-market wheels, since the original wheels usually come with a centre bore of the right size. Usually the hub centric rings are used with alloy wheels, but sometimes steel wheels may need hub centric rings.
The purpose of the centric ring is to perfectly centre the alloy wheel to the wheel hub and hence prevent vibration to the steering wheel during driving and the shaking which typically appears around speeds of 60-100 km/h.