Major flatspots on nearly new tires.

Joined
Sep 10, 2005
Messages
2,537
Location
Erie, PA
Got a winter ride at auction and the car was sitting since 2022 undriven. We drove it 300 miles at highways speeds at 50 psi and the major flatspots did not improve at all.

Any suggestions how to resolve. New tread is 13/32 these are 11/32. Hate to scrap them. They have 2020 and 2021 date codes.
 
Maybe heat them up a bit at pretty low pressure, 20psi? Go a couple miles and see how hot the sidewalls are getting, maybe try for as hot as you can stand holding your hand too, then reinflate and drive before they cool?
Sounds like it was parked with partially flat tires? I guess if they got hot enough times sitting in the sun, they tires may have taken a set that way?
Heating up the tires near vulcanization temperatures with some air pressure in them would probably work? Probably a fine line between getting them round and totally weakening them?
 
Got a winter ride at auction and the car was sitting since 2022 undriven. We drove it 300 miles at highways speeds at 50 psi and the major flatspots did not improve at all.

Any suggestions how to resolve. New tread is 13/32 these are 11/32. Hate to scrap them. They have 2020 and 2021 date codes.
That sounds like a perfect candidate for a Road Force Balance.

My 2009 F150 when purchased new, must have been sitting for some time. As the same thing happened with the Pirelli Scorpion tires. They tried a balance, took it for a drive and the shake was still there, then did a Road Force Balance and put the worst offenders on the back. Also performed an alignment with the "kit" that allows adjustment. In the end the truck was perfect and never again had a balance problem over the next 200K miles.
 
Why would call tires that sit for 2 years nearly new?

Were they pumped up to avoid what you are describing? If they were in full sun backing and with low pressure I can imagine that they may be ruined.

Is one side worse than the other?

Krzyś
 
My advice would be to start by reducing the inflation pressure and running them for a short time to heat them up. 10 minutes? Don't exceed 50 mph. You're just trying to heat up the tires. Speeds higher than that will have significant centrifugal forces that are normally countered by inflation pressure.

In that time you should feel the flat spots go away. If you do quickly reinflate the tires to over 40 psi and let the car sit. If the flatspots return, do it again, but be quicker.

Keep reducing the pressure - say 3 psi at a time - until you get rid of them while driving. If you get to 15 psi below the placard pressure, the flatspots are likely permanent and you'll either have to replace the tires or live with it.
 
Got a winter ride at auction and the car was sitting since 2022 undriven. We drove it 300 miles at highways speeds at 50 psi and the major flatspots did not improve at all.

Any suggestions how to resolve. New tread is 13/32 these are 11/32. Hate to scrap them. They have 2020 and 2021 date codes.
They are almost at end of life by age anyway. Don't be attached or feel bad about tossing old rubber.
 
Why would call tires that sit for 2 years nearly new?

Were they pumped up to avoid what you are describing? If they were in full sun backing and with low pressure I can imagine that they may be ruined.

Is one side worse than the other?

Krzyś

Ahhh.....how about I bought the car as-is, where is. I cannot ever know your questions. Im sure when they drive them from the police station to the auction lot, they have to do some basic tire inflation, fluid top offs, and fuel replenishment to get it there.

The front two are VERY out of round. The rear two are VERY acceptable. I know this as the front end was shaking so bad on the ride home I had to pull over and do an emergency front-to-rear tire rotation. It was so bad that I was concerned it would damage the steering system, which on the crown vics there is a weak bushing on the steering column that can pop out.

I drove it 300 miles home and it did not improve. I will try 25psi and see if they flatten out.

2020 thru 2021 date codes are new for our area. They have 11/32 out of 13 so I classify that as "like new".

They are police tires so for me to buy retail (not in a bulk buy) would cost me $1200 plus install. So the decision is not easy.
 
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