flat spots on tires?

[cinbol]

Hi all - we are looking at a 2005 Sightseer 29R - took it for a test drive today and can detect a small "thumping" as "flat spots" on the tires hit the ground - detected by hearing not feeling in the steering.

Rig was used just over a week ago for a 250 mile round trip week long outing but not sure when it was used prior to that - suspect it has been sitting most of the summer in one place (on gravel)

Current owner has the PSI at 80lbs per recomendation of his dealer.

How long will it take for these flat spots to even out? Is this an issue we should be worried about? - rig has 14K miles on it.

Would love to hear opionions from those who may have "heard of" this issue.

Cindi

[smlranger]

My rig sits for over a month at a time and I've never experienced thumping from flat spots on the tires. I would think that could be an issue if a coach has been sitting in cold weather. At any rate, 'flat spots' on tires usually resolve as soon as the tires warm up. Did the thumping continue even after driving some miles or did you drive only a short distance?

If the tires are the originals, they are at least 5 years old or older depending on the DOT code on the tires. They are near the end of their useful life anyway so you might want to consider that in your negotiations if you want to buy the coach.

[cinbol]

SMLranger - thanks - we did only do a short loop - maybe 5 miles- we were wondering if the tires are inflated properly. Current owner was a great salesman in his time so not sure if everything he tells us is gospel but he's taken good care of the rig and we confirmed that with the dealer who services it. Only 14K on the rig, but we should look at the tires more closely considering the winters here in NE - don't think he ever covered the rig so they have been exposed to all the seasons here.

thx for your insight.

[Clifftall]

I agree with smlranger, in that these tires are approaching the end of their useful life.

[dirko]

Hi Ho: Most MH tires will take a set causing a flat spot that will usually go away after 10-15 minutes of driving. Lots of folks change tires every 5 or 6 years. We usually go for 10-12 years if there are no visible cracks or checking.

You will have to determine what you want to do in this regard.

Dirk

[rowesort]

Quote:

Originally Posted by dirko Hi Ho: Most MH tires will take a set causing a flat spot that will usually go away after 10-15 minutes of driving. Lots of folks change tires every 5 or 6 years. We usually go for 10-12 years if there are no visible cracks or checking. You will have to determine what you want to do in this regard. Dirk

I agree , One of the little known recommendations by the tire manufacturers is to increase the tire pressure to the lower of the max rating of the rim or tire when placing into long term storage. ie MH Manufacturer max rating 90, tire rating 120, Rim max 110. Inflate tires to 110 for storage reduce to 90 or lower based on actual axle weights when bringing out of storage.

This assists the steel belts.

Here is good link

Michelin North America RV Videos and Demos Page

The rating by the MH builder is the max pressure for the coach under maximum load per axle ie 100 front 90 rear(duals) Over inflating can be hard on the suspension.

[cinbol]

Thanks all - we bought the sightseer and the tires evened out during our one hour drive home so all seems well. We are a bit confused about the correct tire pressure and will keep looking on these boards for more advice. Since we store outside but covered in the winter in the NE we will surely be looking at the max rim pressure to assit the steel belts over the winter months - thanks again!