Balance is different from alignment. Alignment is the angle of the wheels relative to the car. Balance is the distribution of weight around the wheel and tire as a unit. A wheel can be perfectly aligned and still vibrate badly if it's out of balance.
What balancing does
A tire and wheel together are never perfectly uniform — the wheel itself has slight casting variations, the tire has uneven rubber distribution, and the valve stem adds weight in one spot. Without correction, this imbalance causes the wheel to wobble as it spins, especially at highway speed.
Balancing finds the heavy spot and adds small lead or steel weights on the opposite side of the rim to cancel it out. A balanced wheel spins smoothly at any RPM.
Signs of an out-of-balance wheel
- Steering-wheel vibration at a specific speed (often 55-65 mph)
- Vibration that disappears below that speed and reappears at higher speed
- Vibration felt through the steering wheel (front imbalance) or the seat (rear imbalance)
- Uneven 'cupping' wear pattern on the tire — wavy depths around the circumference
Static vs dynamic balance
Static balance corrects up-and-down imbalance. Dynamic balance also corrects side-to-side wobble. Modern computer balancers do both as a single operation. Old-school bubble balancers only did static — fine for low-speed driving, not for highway.
Road force balance
Premium balancers (like Hunter Road Force machines) press a load against the spinning tire to simulate the weight of the car. This catches stiff spots in the tire that traditional balancing misses. Worth paying extra for if you've had repeated balance issues that don't go away with normal balancing.
When to rebalance
- Every time you mount a new tire
- Every other tire rotation
- Any time you develop a vibration that wasn't there before
- After significant pothole impact (a weight can fly off, or the wheel can bend)
What balancing costs
$15 to $25 per tire at most shops. Often included free with new tire purchases. Road force balancing runs $25 to $40 per tire.
If you've got a vibration and your tread looks fine, the wheel's not balanced. Cheap fix, dramatic improvement.