Tyre Cupping; what is it, and how do you stop it?
If you’ve never heard of Tyre Cupping, or Tyre Scalloping before, don’t feel bad. It’s not a commonly talked about problem, but in the 4WD, Camper and Caravan world its quite common, and annoying to deal with.
What is Tyre Cupping?
Traditional tyre wear does either the centre of the tyre, or the outside, or one side or the other. Tyre Cupping though, is a wear pattern that causes high and low points on your tyre. Typically, you’ll have one block of tread that is high, with the next one low, and then repeating all the way around. In some cases the blocks can wear heel to toe, and it looks really unusual.
What does Tyre Cupping do?
Most people only notice this sort of Tyre wear when their tyres get noisy, and occasionally you feel more vibration coming from your wheels. As you might imagine, when your tyre is wearing some lugs faster than others, you end up with a wheel that is much noisier on the road, and it whirrs a lot louder.
It also reduces your traction considerably, as your tyre is no longer nicely round on the outside edge.
The most annoying thing though, is that it wears your tyres out much faster than they would do if it was wearing evenly without the cupping. Once it starts too, it can be virtually impossible to recover from, so its critical that you keep on top of how your tyres are wearing, and make changes as quickly as you can.
What causes tyre cupping?
There’s a whole realm of things that can contribute to tyre cupping, and some tyres are much more susceptible to it than others.
Damaged shock absorbers
One of the most common reasons you’ll get tyre cupping is because of shock absorbers that are no longer doing their job. This can be due to failure, but more often than not they’ve just worn out, and are no longer dampening the suspension as they should, resulting in tyres that get uneven amounts of weight, and cause them to wear in a cupping fashion.
Incorrect tyre pressures
If you run your tyres down too low, they’ll bounce and you will get poor wear patterns forming. There’s a number of ways you can work out the correct tyre pressure on bitumen, but sometimes a bit of trial and error doesn’t go astray either.
Poor alignment
If your tyres have not been aligned lately, this can contribute to tyre cupping. Our very own Reconn R2 suffered this terribly until we had offset spindles fitted, which resolved the alignment issues.
Unbalanced tyres
Tyres need to be balanced properly on the wheel, and sometimes this is missed, or not done correctly. Also, weights can fall off, but a tyre that is not balanced properly has a much higher chance of cupping.
Mud terrain tyres are shocking for it
You will never see tyre cupping on a road terrain tyre, and its rare on a normal all terrain tyre too. However, mud terrain tyres are terrible for it, because they have big, chunky lugs with nothing in between them.
Our Reconn R2 Hybrid Camper had a bad problem with tyre cupping, and I’ve seen it on plenty of other trailers running mud terrain tyres. From the moment I went to an all terrain (albeit an aggressive one), the problem went away, and we no longer had a problem.
If you have more rubber touching the ground, it’s a lot harder for the cupping to start, and continue.
How do you prevent Tyre Cupping or Scalloping
Asides from making sure that your wheels are balanced, and your suspension (particularly the shock absorbers) are working correctly, the best thing you can do to prevent tyre cupping is to rotate your tyres regularly and run the right pressures.
That might be every 5000km for mud terrain tyres, because they’re most likely to suffer. If you push the rotations out too long, the pattern will be virtually impossible to stop, and you’ll have noisy, vibrating tyres right to the death of them.
Have you had issues with tyre cupping or scalloping? What did you do about it?
