Hub Centric Spigot Rings: Sizing, Fitment & Vibration Elimination

Why Does My Car Shake at 55–70 mph After Fitting New Wheels?

You have just fitted a gorgeous set of aftermarket alloy wheels and had the tyres brand-new and balanced. Yet at highway speeds, an annoying vibration rattles the steering wheel. 99% of the time, the culprit is missing hub centric spigot rings.

1. What Is a Spigot Ring and Why Is It Necessary?

To fit as many different cars as possible, aftermarket wheel manufacturers produce alloy wheels with a large, generic center bore (often 73.1mm or 72.6mm). However, your vehicle's metal hub spigot lip is significantly smaller (e.g. 63.4mm on a Ford, 57.1mm on a VW).

Without a spigot ring:

The wheel is held in place purely by the friction of the wheel bolts ("lug-centric").
Because bolt holes have minor clearance tolerances, the wheel will be mounted slightly eccentric (off-center) by just 0.2mm to 0.5mm.
At 60 mph, your wheels spin over 800 times a minute. That tiny 0.5mm off-center rotation produces severe, rhythmic steering oscillation.

A spigot ring fills that gap with 100% concentric precision, ensuring the car's weight is carried directly on the hub lip.

2. How to Read & Measure Spigot Ring Sizes

Spigot rings are designated by two numbers: Outer Diameter (OD) → Inner Diameter (ID) in millimetres.

Outer Diameter (OD): The exact internal diameter of the center bore recess on the back of your alloy wheel. Measure this with digital vernier callipers (e.g., 73.1mm, 72.6mm, 66.6mm).
Inner Diameter (ID): The exact external diameter of the protruding metal spigot lip on your car hub.

3. Common UK Vehicle Hub Lip Sizes (ID)

Vehicle Make / Model	Hub Diameter (ID)
Ford (Fiesta, Focus, Mondeo, Transit Connect)	63.4 mm
BMW (Most 3, 4, 5, 6, 7-Series, E46, E90, F30)	72.6 mm
BMW (5-Series E39 only)	74.1 mm
Volkswagen / Audi / SEAT / Skoda (Golf Mk5+, A3, Leon, Octavia)	57.1 mm
Audi (A4 B8+, A5, A6 C7+ 2008+) & Mercedes-Benz	66.6 mm
Vauxhall Vivaro A / Renault Trafic II / Nissan Primastar	71.1 mm
Vauxhall (Astra H/J, Corsa D/E, Vectra C 5-stud)	65.1 mm or 56.6 mm

4. Plastic vs Aluminium Spigot Rings

A common myth is that aluminium rings are "stronger" than composite rings. In reality, spigot rings only center the wheel during installation — once the wheel bolts are torqued, clamping friction holds the wheel. Furthermore:

Aluminium rings suffer from galvanic corrosion: Road salt and moisture create an electrolytic reaction between the steel hub and aluminium ring, effectively welding the ring to the car. Drivers frequently have to chisel them off during tyre changes.
High-Grade Polycarbonate Rings: Will never corrode, seize, or bond to your alloys, while easily withstanding intense brake disc heat on road and track.