Hub Centric Rings

Most aftermarket wheels are manufactured with a large center bore so that one wheel design can fit many vehicles. Your hub is smaller than that bore, which leaves a gap. A hub centric ring is a precision sleeve that fills the gap so the wheel is located by the hub rather than by the lug nuts.This matters because of how the load is meant to be carried. When a wheel is hub centric, the hub carries the vertical weight of the vehicle and the lug nuts only provide clamping force. When a wheel is lug centric with a gap at the hub, the lug hardware carries both jobs. The usual symptom is a vibration at highway speed that no amount of rebalancing fixes, because the wheel is not centered on the axis of rotation. In the worst case it fatigues studs.Rings are specified by two numbers: outer diameter, which must match the wheel bore, and inner diameter, which must match your hub. Aluminum rings are more durable and better in salt-belt climates; polycarbonate rings are cheaper and will not corrode themselves onto the hub. Either way, apply a little anti-seize and check them when you rotate tires.