How to Measure Wheel Offset – FYI

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(Newswire.net — October 21, 2019) — Do you know how to measure wheel offset, or the backspace? Which is the one you need to know when mounting your tires? Well, the answer is simple: you need both. You might have surely bumped into the wheel offset vs backspacing question when you were browsing for the many ways to mount a wheel on a truck, according to the hub, the tires and even the type of rims your wheel is using, so it’s understandable if you feel a bit lost in this equation. And yet, it’s important that you answer this question as soon as you can, as trying to mount a wheel without any knowledge of the zero, positive or even negative offset wheels problems that can bring an inadequate measure calls for catastrophe.

How to Measure Wheel Offset

From different types of tires to wheels, cars have various aspects to them. In order to avoid the potential dangers of inadequate mounting, read below for the basics of both offset and backspacing mounting. We’ll explain their main differences and how you can properly measure the wheel offset and backspacing for a safe mounting procedure.

Wheel offset vs Backspacing

Offset refers to the distance between the wheel’s hub mounting surface and its centerline. There are three offset types: zero-wheel offset (the surface is in line with the wheel’s centerline), positive wheel offset (the surface is facing the street side of the wheel’s centerline) and negative offset (the surface is behind the wheel’s centerline).

Backspacing, on the other hand, is the distance your wheels and tires need to be at in order to adjust both the offset and the wheel width.

Getting the measurements of these two wrong equals a terrible driving experience.

How Can You Measure a Wheel Backspace?

You can easily measure backspace by placing the wheel face down onto the ground so that the backside is facing up. Lay diagonally one of the straight edges across the wheel’s inboard flange and measure the distance between where the edge touches the flange and the hub mounting pad.

Afterwards, you can easily measure the offset.

How Can You Measure the Wheel Offset?

Once you’ve measured the backspace, measure this time the wheel’s width and its centerline. Afterwards, it’s time to do some math: subtract the wheel centerline’s inches from the backspace; the result you get is the offset.

If the backspace’s measurement is less than the wheel centerline, then the offset is negative. However, if it’s greater, then it’s positive. Mount accordingly and that would be it.

Now, some final considerations.

Is wheel offset bad?

Of course. It will damage the wheel’s inner flange and even the suspension components it rubs. And if your tire rubs a lot, it will rip very quickly up its inner sidewall and increase the chance of the tire exploding.

How do you read rim sizes?

Firstly, locate the stamped size on the rim’s back hub. You’ll see several numbers there, which are the diameter, width and bolt pattern measurements. For example, if you see 14 by 6 by 4.5, it means that the rim’s diameter is 14 inches, and will accommodate most 14-inch tires.

What are the different types of wheels?

There are various types of wheels. The most common ones are forged steel wheels, the cast iron wheels and the flow forged wheels. Other ones, however, are ductile Iron, polyurethane, mold on rubber, NyTec-MD, phenolic resin and the V-Groove. You also have three piece wheels which are similar to forged wheels. 

We hope that our article helped you understand how to measure wheel offset and backspace distances, and that you feel ready to properly mount your wheels according to their size, tire and type of rims. As you can see, it’s not so much about which is more important in the wheel offset vs backspacing debate, but rather understanding how both help you avoid the zero, positive and negative offset wheels problems which, as we described above, can be fatal if you’re not careful.