So, my car had to sit for 6 weeks due to a bad starter. This weekend it got fixed finally and I was able to drive it this morning for the first time. It feels like the tires have flat spots on them now and there is a vibration at speed. Will they round themselves back out eventually or do I need new tires? They are fairly worn, but I cant afford tires at the moment.

 

If they are radials then they will work themselves back into round. Bias-Ply tires are the ones that will develope flat spots that don't go away.

 

Thanks for the quick reply! Yeah they are Cooper Cobra Radial GTs so they should be ok then. Thanks again!

 

if you really want to be sure if they are out of round you can have them road force tested but if you dont have funds for new tires that probably isnt feasible.

 

Yeah thats not going to happen. It just feels like they are out of balance at higher speeds and you can feel the car bounce up and down a little at low speed. Im sure as RedLeader said, they will round themselves out as the heat up in the sun. They spent 6 weeks in the hot Florida sun in the same exact spot on pavement. Im sure they got soft in that time frame as it was 90+ for at least 4 of those weeks.

 

Tires can flat spot over night, the longer they sit the longer a drive it will take to get them to round out. It is also possible to have such a severe flat spot that it cannot be removed and replacement or tolerance of the vibration are the only options. Unfortunately, a Road Force Variation machine will NOT remove flat spots. In fact, the first step before taking the tire/wheel assembly off the car when performing RFV measurement is to drive it for at least 15 miles in order to remove flat spots. People who have very soft compound tires and have vehicles that sit for long periods of time will either over inflate their tires to minimize flat spotting or will raise the tires off the ground to remove all possibility of flat spotting.

 

Hopefully it works its way out. I've got some 31" tires that never worked their RFV out

 

Well it's been 10 days now. The drivers side tire rear has rounded back out, but the passengers side isnt cooperating. It feels like a flat tire when driving at low speeds then shakes like it's out of balance at high speed. There is no visible flat spot. I need new tires in the near future anyway, so I will just ride it out for now, just kind of sucks.

 

There's always the possibility that it did throw a weight at some point.

 

I thought of the weights too, but the car bounces up and down at 1 mph and bounces faster at 2 mph, then faster and faster as you accelerate. It wouldnt show balance issues at those slow speeds.

 

That's true. rotating it to the back might help/make it less noticeable (if your tire sizes alow for front to back rotation)

 

Lol! That would be a great solution, but it's the passengers side rear thats the trouble. I know I dont want to rotate it to the front, that would suck having that shake in the steering wheel. Im just going to live with it until I can finally swap out the tires for new.

 

Ah! I misread that, good call. As a totally viable option you could always just burn the flat spot off haha

 

Im thinking thats my next option, especially being a one legger and it's on the passenger side, so thats the tire that gets power most of the time.

 

So, the burnout didnt really help as the flat spot was more in the sidewall of the tire (at least I assume it was) but it sure was fun! Anyhow, after 2 weeks of daily driving, it has FINALLY worked itself back into round. Now it really feels out of balance at speed (worse vibration than when it was flat spotted) but the low speed bounce is gone. Anything under 40mph is smooth now when before it shook no matter what speed you were going. So hopefully this weekend I can bring it in and get the tire re-balanced.

 

Just an update... the tire is junk now. It has separated badly. I didnt see it when looking the other week (I figure the bad spot was against the ground), but the problem was getting worse, so I took it to a tire place yesterday. As we walking up to the car the tech goes, that tire is bad before we even got to the car. The bad spot happened to be facing us as we were walking. I know I would have noticed it, I even ran my hand over the whole tire (minus the spot on the ground) so again the car sits until I can afford a tire, which should be next week. It also sucks because I can only really afford one tire, so I will have one brand new one, two fairly worn ones (currently in front), and one very worn one.