ALLOY WHEEL UPGRADE OPTIONS

Alloy wheels are a great way to add style to your motorhome and they're ideal for replacing a tired set of steel wheels or as part of an upgrade to a different tyre size. But before you simply bolt a set on, what do you need to know?

- Peter Rosenthal

While many motorhomes are fitted with a smart set of alloy wheels, not all are and some of these factory wheels can be quite boring and, in the case of older wheels, can really limit your tyre options. These days there are all manner of cool wheel options to upgrade the look of your motorhome and personalise it to your preference. Probably the best time to do it is when your tyres need replacing, because many specialist firms offer deals on wheels and tyres bought together. Whatever your reason for wanting to upgrade to a new set of alloys, there are a few things to be aware of before you simply bolt the new set on. So let's get into it!

THE BASICS OF WHEEL SIZING

Wheels and tyres are sized in a curious mishmash of metric and imperial sizes that can be quite bewildering to the uninitiated. Wheel diameters and widths are usually quoted in inches (measured from the inner rim of the wheel - not the outer bit you can see), such as 17-inch diameter and 7-inch wide. Their bolt pattern is usually four, five or more bolts (or nuts, if studs are fitted) and is commonly quoted in millimetres and referred to as the Pitch Circle Diameter (PCD). The PCD varies between all vehicles and can change from model year to model year on the same vehicle.

The offset (or Einpresstiefe in German - 'insertion depth') refers to where the mounting face of the wheel sits, relative to the centreline of the wheel. A wheel with zero offset (ETO) would sit in the exact centre of the wheel, while one with positive offset would sit more inboard. A negative offset wheel will sit further away from the bodywork.

This offset is usually stamped on the reverse of the wheel - often on the spokes - and denoted by 'ET' with a number next to it. For example, 'ET -5' would indicate a negative offset of 5mm relative to the wheel centreline.