Symptoms
- Wavy, scalloped dips around the tire's circumference
- Noticeable vibration or noise that gets worse with speed
- Rougher ride than before
- Wear feels uneven when you run a hand across the tread
Likely causes
- CommonWorn shocks or strutsShocks control tire bounce; when they wear out, the tire hops slightly and wears unevenly.
- CommonWheel out of balanceAn unbalanced wheel bounces at speed, creating cupped wear over time.
- PossibleWorn wheel bearingPlay in the bearing lets the tire wobble slightly against the road.
- PossibleBad alignment or worn bushingsLoose or misaligned suspension parts let the tire hop instead of tracking smoothly.
What to do
- Run your hand across the tread front to back to feel for a wavy pattern.
- Note when the vibration or noise happens: constant, only at certain speeds, or over bumps.
- Have the tires balanced first since it's the cheapest thing to rule out.
- Have the shocks or struts inspected for leaking fluid or bouncing test failure.
- Ask about wheel bearing play and suspension bushing wear if balancing doesn't solve it.
- Replace or repair whichever component is confirmed worn, then rotate or replace tires as needed.
Tools and parts
Replacement shocks or strutsSearch: “shocks or struts for [your car model]”
Wheel balancing weightsSearch: “wheel balancing service”
When to call a pro
A suspension or alignment shop should diagnose the root cause; replacing tires without fixing the underlying issue just wears the new ones the same way.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.