Tires

[joemikeb]

Originally Posted by 73shark

I believe the cupping is due to an alignment issue. Anytime you purchase new tires for a vehicle, you should get it aligned.

I have been told by three reputable tire stores that "cupping" is endemic on vehicles made in Germany including Mercedes, BMW, and Volkswagen. The implication being U.S. built models from the same manufacturer are not as likely to evince the problem. No explanation of why that is was offered, but the solution offered is being sure to rotate the tires often. It does not eliminate the cupping, but equalizes the wear.

[73shark]

Originally Posted by joemikeb

I have been told by three reputable tire stores that "cupping" is endemic on vehicles made in Germany including Mercedes, BMW, and Volkswagen. The implication being U.S. built models from the same manufacturer are not as likely to evince the problem. No explanation of why that is was offered, but the solution offered is being sure to rotate the tires often. It does not eliminate the cupping, but equalizes the wear.

Probably a conspiracy between the Germans and the tire manufacturers.

I wouldn't be so paranoid if everyone wasn't out to get me.

My front tire wear was confined to the outer rib and was uniform, not cupped. From what I've been told over the years was that cupping was usually caused by worn shocks.

[Protagonist]

Originally Posted by joemikeb

The implication being U.S. built models from the same manufacturer are not as likely to evince the problem.

As far as I know, every Sprinter van comes off the same assembly line in Dusseldorf, so that would be a moot point. There are no American-made Sprinters that I know of.

I haven't seen any uneven tire wear at all on my Interstate. No cupping, no excessive outer edge wear, no excessive inner edge wear, nothing.

Mind you, I only have 20,000 miles on mine, so maybe it's a problem that will show up as I get more use out of it…

[Boxster1971]

Cupping normally means your tires are not balanced properly. Uneven wear on front is normally an alignment problem. I've have no such problems with my new Michelins in over 15,000 miles.

[Moflash]

If your tires are cupped on just the outside edges or inside edges your vehicle is out of alignment.You can rotate them but they will not ever smooth out and will whine until replaced.Replace front tires and align and all will be good again.


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[73shark]

Originally Posted by Moflash

If your tires are cupped on just the outside edges or inside edges your vehicle is out of alignment.You can rotate them but they will not ever smooth out and will whine until replaced.Replace front tires and align and all will be good again.


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Could you elaborate on which element(s) of alignment (caster, camber, toe) contribute to cupping?

[CapriRacer]

Originally Posted by 73shark

Could you elaborate on which element(s) of alignment (caster, camber, toe) contribute to cupping?

Mostly it is toe. Camber can play a role, but to a lesser extent. Where it gets interesting is that both camber and toe can reinforce each other and the result would be worse than the sum of the 2 by themselves.

[Moflash]

To much toe in will cause excessive outside tire rib wear with cupping toe out will cause excessive inside rib wear with cupping.Excessive camber will cause more even excessive wear without cupping normally on the inside or outside of tires tread.Under inflation will cause excellerated wear both inside and outside rib usually without cupping.Over inflation will cause excellerated wear in the middle of the tires tread.
Hope this helps.


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[Protagonist]

I suppose it helps in my case that I installed my Koni shocks and front struts early on— rather, I had Mercedes Benz of Baton Rouge do it for me, and they did a front end alignment at the same time, even though the instructions with the Konis said that no realignment was necessary after installation.

Having gotten a front-end alignment with my full load (full fresh water tank, full propane, full diesel tank, everything but me in the driver's seat) is probably why I've not experienced the same problems as you describe.

[CapriRacer]

Originally Posted by Moflash

.......Under inflation will cause accelerated wear both inside and outside rib usually without cupping.Over inflation will cause accelerated wear in the middle of the tires tread.
Hope this helps.

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That part isn't quite right.

First, there are other things that have a greater affect than inflation pressure. For example, steer tires tend to wear on the shoulders and drive tires tend to wear in the center. So even properly inflated tires will show symptoms that most folks would view as over/under inflation.

Inflation pressure does affect cupping. It's kind of a multiplier - too low and the cupping gets worse. It's not a direct cause, but it does affect the results.

[Moflash]

I agree with you,just trying to simplify description for novice drivers.


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[73shark]

And weak shocks/struts can cause cupping.

[Prairie]

Thanks for all the good advice and discussion on "Tires". I didn't realize I was opening a topic with so much interest and experience. Being new to the Forums I am impressed with how valuable this tool will be as I continue my adventures in the world of RVing. I am now at a Chrysler dealer that services Sprinter for front end alignment with new Michelin LT215/85R16 LTX MS2 tires.
Again, thank you all,
From the "Prairie Schooner"

[73shark]

Hope their rig can handle the long wheel base. Mine couldn't.