A spigot ring (o ring / hub ring / spacer ring) is made from from poly-carbonate or metal.
The purpose of a spigot ring is to centralise the wheel perfectly on to the hub of a vehicle, the correct size will ensure optimum fitment and prevent any wheel vibration or steering shake at high speeds.
The ring is designed to fit flush into the back of an alloy wheel so that it can be mounted securely on to the hub of the vehicle. For example, the BMW e30 has a hub diameter of 57.1, BBS wheel has a diameter of 63.4mm, in this instance you would have to use the 57.1 - 63.4 spigot rings.
We can custom manufacture spigot rings in forged aluminium for any size as low as 0.5mm difference, eg 66.6 - 67.1.
You may not be able to find the exact size you need at your local Halfords or Euro Car Parts, give us a try, we manufacture these rings.
Spigot rings are made to fit perfectly into the back of a wheel, thus reducing the centre bore so that the wheel fits nice tight and snug on the hub of the vehicle.
Correct size spigot rings will prevent any sort of wheel vibration and steering shake which may occur at high speeds of 60mph and above.
For example, an Audi A4 2006 has a hub size of 57.1mm, the new shape 2010 Audi A4 wheel has a 66.6 centre bore, therefore you will need the size 57.1 to 66.6.