Every winter, Victorian roads take a beating. Weeks of rain soak into the road surface, traffic works the cracks open, and before long a smooth stretch of bitumen has sprouted a crop of potholes. Most of us hit one eventually — often in the dark or the rain, with no time to swerve. That single thump can do more damage than you might think, and not all of it is visible from the driver's seat.
What actually happens when you hit a pothole
When your wheel drops into a pothole, the tyre and rim cop a sharp impact rather than the gradual load they're designed for. The tyre's sidewall gets pinched between the edge of the hole and the wheel rim, and the suspension is jolted well beyond its normal range. Depending on your speed, the depth of the hole and how much air is in the tyre, a few things can go wrong: the sidewall can bruise or bulge, the rim can bend or crack, and your wheel alignment can be knocked out in an instant.
Kerb strikes do similar damage in slow motion. Clipping a kerb while parking, or mounting one at an angle, puts a scraping and twisting force on the tyre's shoulder and the edge of the rim. It feels minor at the time, but repeated kerb contact is one of the most common causes of sidewall damage we see.
The signs to look for after a hard hit
If you've had a decent thump, it's worth pulling over somewhere safe and having a look. Keep an eye out for:
- A bulge or bubble in the sidewall. This means the internal cords have been damaged. A bulging tyre can fail suddenly and should be replaced, not repaired.
- Cuts, gouges or exposed cords. Any damage deep enough to show the fabric or steel beneath the rubber makes the tyre unsafe.
- A visibly bent or cracked rim. Alloy wheels can crack rather than bend, and a hairline crack may only show up as a slow, unexplained loss of pressure.
- The car pulling to one side or the steering wheel sitting off-centre when you're driving straight — classic signs the alignment has been knocked out.
- A new vibration through the steering wheel or seat, which can point to a bent rim or a tyre that's out of balance.
Why the hidden damage matters
The tricky part is that pothole damage doesn't always announce itself straight away. A slightly bent rim might just cause a slow leak that you put down to bad luck. Alignment that's a few millimetres out won't feel dramatic, but it will quietly scrub the edges off your tyres over the following months, costing you tread life and fuel. A bruised sidewall can look fine for weeks before the weakened spot lets go — usually at highway speed, when you least want it to.
That's why the general rule is simple: if the hit was hard enough to make you wince, it's hard enough to be worth checking properly.
How to protect your wheels through winter
You can't dodge every pothole, but a few habits reduce the risk. Keep your tyres inflated to the pressure listed on your car's tyre placard — an underinflated tyre offers far less protection to the rim. Leave a bigger gap to the car in front in the wet so you can see the road surface earlier. If you can't avoid a pothole safely, slow down before it and roll through rather than braking hard in the hole, which loads up the front wheels and makes the impact worse. And after heavy rain, be especially wary of puddles — a harmless-looking sheet of water can hide a deep hole.
It's also worth glancing over your tyres and rims once a fortnight through winter. Thirty seconds with your eyes (and a quick pressure check) will catch most problems while they're still cheap to fix.
If you've clouted a pothole or kerb and something doesn't feel right — or you'd just like peace of mind — the team at Global Tyres Geelong in North Geelong can inspect your tyres and rims and check your wheel alignment while you wait.