Flat Spot on Wheel

Parent Cafe
1

I’m confused about a car issue (nothing new for me!). When D’s old Subaru got its last tire rotation (first rotation on new tires), they said there was a small “flat spot” on one of the wheels. They said it could cause some vibration, but is safe to drive with. It was in the front after the rotation, but they said it would probably vibrate less in the back. They said they could replace the wheel for $200-$300. I’m confused by that. It is more than the tire cost. Isn’t that part of a new set of tires? Or is the wheel something separate? When they rotate tires, do they move both the tire & the wheel? Or is the wheel always in the same place, and did they just mean that if it had happened in the back, we’d feel it less?

2

When car tires are rotated, each wheel and tire is moved as a unit.

Flat spots on tires are described at https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=42 .

3

Wheel = metal part. Tire = rubber part. “Flat spot” on wheel = dent on the metal part. Most likely from hitting a pot hole, or perhaps a curb. Generally speaking an out-of-balance or flat spotted wheel is more noticeable when mounted on the front as it will be felt through the steering wheel as a shaking or vibration. Putting a dented wheel on the rear is less noticeable to most drivers.

4

Thanks. :slight_smile: The hive mind comes through again!

5

These terms may be confusing because they tend to be used without precision. However, if you think of a wheel as being composed of a rim and a tire, the following should apply:

  1. Rims and tires remain together during rotations.
  2. Flat spots generally occur on *tires*, but one could occur on a *rim* as well. If significant, either would affect road performance because the *wheel* would be "out of round" as a *unit*, even after balancing.
  3. Any wheel problems will be less consequential if on the rear of the car.

What to do?

  1. Your daughter can ask if she has a tire problem or a rim problem.
  2. If she has a tire problem, then a new tire obviously would eliminate the issue.
  3. If the rim is imperfect, then you could replace that part, which would similarly solve the problem.
  4. She could rotate the problem wheel back to the rear for a quick fix.
  5. She could leave the arrangement the way it is now until further rotations and tire replacements. This ultimately would resolve any issue other than an imperfect rim.