How do potholes damage a car beyond the tires?

Why a hole in the road hits like a hammer

The destructive part is the exit lip, not the depth. The tire drops into the void and slams the far edge on the way out — an impact concentrated into a few centimetres of travel at whatever speed the DVP was moving.

Suspension absorbs energy by moving through its stroke. A pothole edge allows almost no stroke — enormous force, no distance — so instead of being absorbed, the blow transmits raw into the rim, the strut, and every mounting point above them.

Modern wheel fashion makes it worse. Low-profile tires leave a thin cushion of sidewall between road and rim, which is why today’s 19- and 20-inch wheels bend far more often than the tall-sidewall 15s of an older generation. Heavier vehicles — EVs very much included — bring more mass to the same collision.

The actual casualty list

The damage inventory runs far past rubber, and most of it hides where a walk-around cannot see:

• Bent or cracked wheels — steel rims fold, alloys crack, and a cracked alloy will not hold air
• Sidewall bulges — broken internal cords, and a blowout waiting for a hot day on the 401
• Blown struts and shocks, plus crushed strut mounts and bearings
• Bent control arms, tie rods, and knuckles, which lock the misalignment in permanently
• Snapped coil springs, often silent until a clunk develops
• Hammered wheel bearings and CV joints
• Cracked lower bumper covers, torn air dams, and underbody shields dragged loose
• Bent exhaust hangers and dented exhaust runs
• On the hardest hits, movement at the subframe mounting points in the shell itself

Alignment and sensors: the quiet consequences

A hit that shifts camber or toe even slightly starts eating a tire immediately — a few thousand kilometres is enough to scrub the inside shoulder bald — and the car will tug toward one side long before the wear becomes visible.

The subtler casualty is driver assistance. Forward cameras and radar are aimed relative to the vehicle’s thrust line and ride height, so a knocked alignment or a replaced suspension part can leave them pointing somewhere slightly wrong. Plenty of manufacturers require a formal calibration after alignment or suspension work for precisely this reason.

Stability control leans on the steering angle sensor to know where the wheels are pointed, and that sensor needs resetting after alignment corrections on most vehicles.

This is what catches people off guard about one bad pothole: a single impact can leave a car out of alignment, out of sensor aim, and outside the assumptions its safety systems were calibrated under — simultaneously, with nothing but a thump to show for it.

Your post-impact checklist

Some checks work in a parking lot; the rest need a hoist. Do the easy ones immediately, and stay alert through the following week:

• Inspect the rim for a flat spot, a lip out of round, or a hairline on the inner barrel
• Search the sidewall for any bubble or bulge — that tire is done, park it
• Notice whether the steering wheel still sits centred going straight
• Notice any new drift or pull on level pavement
• Listen for fresh clunks over bumps or a vibration at one particular speed
• Watch for driver-assist warnings, or cruise and lane-keeping behaving out of character
• Look underneath for hanging shields, torn liners, or dripping fluid
• Recheck tire pressures for a slow leak from a bent bead seat

Pothole season, claims, and the City

Potholes are freeze–thaw made visible: water seeps into pavement cracks, freezes and heaves the surface, and traffic punches out the weakened patch. The GTA runs that cycle relentlessly from February into April, which is why the worst weeks for Toronto roads are also our busiest for wheel and suspension damage.

They are hardest to dodge exactly when they are freshest — a new pothole has a square-cut edge, and one brimming with meltwater reads as an innocent puddle. When avoiding one safely is impossible, brake hard before it and release as you cross, letting the suspension use its full travel instead of hitting while compressed.

On the claims side, striking a pothole is a collision claim on an Ontario policy — you hit an object — so your deductible applies, and as a single-vehicle loss it is scored at fault under the Fault Determination Rules. Weigh the repair number against the deductible and the premium consequence before filing.

Claims against a municipality exist on paper and rarely pay in practice, since cities generally must have known about the specific defect and had reasonable time to fix it. Report the pothole to 311 anyway — if nothing else, it spares the next driver.

How we assess a pothole hit

We follow the force: wheel and tire first, then suspension and steering, then structure. If anything under the floor looks disturbed, the car goes on the measuring system and gets compared against factory dimensions — and you receive the before-and-after numbers in writing.

Cracked covers and torn shields are repaired or replaced, and wherever the manufacturer requires calibration after alignment or suspension work, that operation goes into the repair plan and gets completed before delivery — never left as an optional extra.

If you hit one hard enough to wonder, that is reason enough to check. Send photos or call (647) 594-3401 and we will tell you honestly whether it needs an inspection or just a shrug. Most of the time it is the shrug — and the peace of mind is free.