This article was first published in 2004.
If you've bought alloy wheels from another make of car, or you’ve picked up
a secondhand set of aftermarket alloys, the chances are that the centre hole won't be a good fit for the hub of your car.
That’s right, even if the stud
pattern and the offset are correct, the size of that round hole right in the
middle of the wheel is important.
If it’s too small, it won’t let the wheel fit
on your car’s hub. And if it’s too big, the wheel won’t be properly centred on
the hub, leading to vibration at speed. The solution is to have
centre-ing rings machined-up. It’s a job that can be carried out at alloy wheel
In this story we follow the process step by step as carried out by Dupulu
Wheel Reconditioning on Australia’s
So what exactly is the problem, then? Here is the hub of the car. You can see
that a collar protrudes from the centre of the hub, one that the wheel needs to
And here’s the centre wheel opening. In the case of this wheel and this hub,
the wheel centre hole was too large by about 5mm. That allowed the wheel to be
fitted, but all the centre-ing then depended on the wheel nuts.
The first step is to remove the tyre from the wheel.
Once this has been done, the wheel is spun up on the balancing machine so
that it can be checked to be running true – that is, not out of round or
The diameter of the wheel hole is then measured, being compared to...
...the diameter of the hub's projecting collar.
Centre-ing rings are used a lot in aftermarket alloys to match the wheel to
the hub, so Dean went through a box of surplus rings to find a set that would be
most suitable for the application.
He knew no off-the-shelf rings would suit, so what he was looking for was a
ring that was slightly smaller in internal diameter and slightly larger in
external diameter than the required size.
The rings are made from aluminium alloy and come with a chamfered front face
that allows the wheel to be easily slid onto the hub.
Small projections are located on the outside of the rings so that when
they’re pressed home into the wheel, they’ll stay there.
In order that these projections could be utilised, Dean decided to increase
the size of the wheel hole a little and then machine out the inner diameter of
the ring to match the hub. He measured the outside diameter of the ring and
...used his huge lathe to machine out the centre hole of the wheel to match the
ring. In fact, he machined out only a rear recess so that the ring could be
pressed in from the back of the wheel.
When the inner opening reached the right diameter....
...the ring could be pressed into place.
The inner diameter of the ring could then be machined out to match the projection on the hub. Told you the lathe was huge....
A test-fit of the wheel showed that the clearances were correct – it’s a snug
Here’s what the installed ring looks like from the front, centre cap
And here’s the installed ring, viewed from the back.
The tyre is refitted, the wheel balanced...
..and then refitted to the car. Multiply that process by four and the job is
Depending on whether the rings need to be machined-up from virgin bar or existing rings can be adapted to suit (as was done here), the cost is around AUD$200-$300 for
a set of four. That price includes tyre removal and refitting and