Protection support plates
A protection plate fits over the centre hole clamping of your tyre machine. It keeps dirt and metal contact away from the clamping disc and the centring part, right where the rim is clamped. Order by the make and model of your machine, because the fit differs per support plate. If in doubt, measure the old plate: outside diameter, inside diameter and thickness. That prevents play and keeps the rim centred. The plates fit machines from Ravaglioli among others. For the rest of your tyre changer there is also clamping jaw protection and tyre lever protection.
Choosing centre hole clamping protection
Which size fits your machine
The fit of a protection plate depends on the support plate it goes on. When ordering, state the make and model of your tyre machine, then you know which plate belongs with the centre hole clamping that is on it. If you are unsure between two sizes, measure the old plate. Lay it flat on the workbench and note the outside diameter, the inside diameter and the thickness. A plate that sits too loose will shift during clamping. A plate that is too small does not cover the edge of the clamping disc.
When to replace the plate
A protection plate is a wear part. As soon as it cracks, warps or wears down at the edge, it no longer covers the clamping disc and dirt still gets onto the centring part. Lay a new plate next to the old one and check whether the shape still matches. For the clamping itself there is also cone centre hole clamping protection and Butler centre clamping punch.
Difference from other protection
This plate belongs to the centre of the machine. For the jaws that grip the rim edge there are separate parts, such as clamping jaw protection. If you replace both, you keep the whole clamping clean. When ordering, look at the shape of the recess in the plate, because it follows the support plate of your machine.