How do work out what size spigot rings my alloy wheels use?
Most of the time a brand of alloy wheel will use the same od on all designs eg Rimstock alloy wheels all use 73.1, so let use know what alloy wheels you have and should know what you need. However with so many alloy wheels coming from the far east, a standard size is trickier to know, so you will need to measure the centre bore of your alloy wheels. The picture below shows what to measure, it is the internal measurement that is the important bit not the tapered lip.
