Cupping issues

[NeilageInc]

You need to rotate your tires every oil change or more if you don't like to do oil changes. 5k miles is about max unless you like wasting money. Cupping only happens on the front tires cause they are the steering tires. You will need to rotate them in a cross pattern to get optimal ire wear. LF-RR RF-LR and bring the rears forward. Tire pressure is also a huge factor. If you run more psi you will get better fuel mileage but you are wearing in the center of the tire. Over inflation can also cause the tread to separate from the webbing. I've changed a lot for these reasons and the manufacturer will not warranty over inflated tires. Just my 2 cents. I have more than 6 years of changing tires everyday and have never had a set of tires last less than 60k miles. Thanks Neil.

[bobbyblaze]

Hey now, Don't mean to hijack the thread but I keep seeing the tire's load rating being referred to as a letter designation. Am I missing something ? As far as I understand, the load rating on all tires have a numerical designation.
The last letter in a standard tire size indicates the number of layers used in the construction of the tire. If there is no letter, the tire has the standard 4 plies. A "C" indicates 6 plies, a "D" indicates 8 plies, and an "E" indicates 10 plies. The higher the number of plies in a tire, the stronger the tire is and the more air pressure the tire can safely hold. Higher ply tires require more air pressure to maintain proper wear. That pressure seems to vary from manufacturer to manufacturer and tire construction to tire.
Personally, I would not inflate my tires based on the recomended pressure on my door jamb or owners manual if i don't have the stock tires on that vehicle that the guide was made for, rather follow the actual tire's manufacturers guide and go from there.

As far as I understand, the load rating on all tires has a numerical designation. Here's a portion of the load rating chart. . . left number is the load rating followed by the weight designation.

100-1764 lbs
101-1819
102-1874
103-1929
104-1984
105-2039
106-2094
107-2149
108-2205
109-2271
110-2337
111-2403
112-2469
113-2535
114-2601
115-2679
116-2756
117-2833
118-2910
119-2998
120-3086
121-3197
122-3307
123-3417

[bartonmd]

Bobby is mostly right... I run load range D tires on my truck, even though it calls for load range E, because I'm running a wider tire and the load rating is the same on the stock E as the oversise D...

On the other side of the coin, the load range, like stated, is basically the sidewall stiffness, and different sidewall stiffnesses will require different pressures for even wear.

You say "follow the tire manufacturer's guide?? Is there a weight/pressure chart for a given make/model/size of tire online? I'm positive you aren't talking about the max pressure rating (for max load) on the side of the tire?

Mike

[bobbyblaze]

I was basing the inflation thing on us offroaders running larger than stock size tires. The owners manual recommended pressure is for stock size/construction type tires.
The max tire pressure for each tire is different so the optimum operaing pressure for each tire is based off that particular max. I have had tires with 35 psi max and I have also had tires with a 75 lb max inflation pressure. Personally, I wouldn't run 75psi tires at 35lbs around town.

I'm currently rolling on Hankook ATm RF10 245/75-16 with a max pressure of 44psi. At 90% the running pressure that would be around 39 1/2 psi. I run them at about 37-38psi and with close to 10,000 miles on them, they still look almost new.

I copied this from HankookUSA tires web site. . .

"Generally, the optimum inflation pressure is about 90% of the maximum level. For high-speed driving, drivers are recommended to use a higher than normal pressure"

http://hankooktireusa.com/Serv/Inflatio ... ChildNum=4

[bartonmd]

That's true for most 35psi tires...

I ran my OEM tires at 37-38psi and rotated them every 5k... When I replaced them, the center tread was at the wear bars, and the side tread was 3-4/32 above the wear bars... Those were 44psi tires, stock load rating, for this vehicle...

My truck was running stock size load range E 80PSI tires at 60PSI... They were all worn down the center, just like the tires on my TB were... Ended up they wore correctly at 50PSI front, 40PSI rear (empty) , but it's a 7k# Dodge Cummins truck, and they were 235/85-16...

I'll say it again... Max pressure is for max load. If your car weighs 90% of max load the tires are rated for, then 90% of max pressure is probably fine... If your vehicle weighs 40% of max load for the tires (as is typical for oversize + load range E tires on small vehicles...), then 90% of max load pressure will cup and wear the centers out of them...

Mike

[bobbyblaze]

Hey Mike, i'm wasn't trying to get into a pissing contest with you.

You checked me on the manufacturers pressure guide and I backed up what I was saying by quoting the 7th largest tire manufacturer in the world. . . ."You say "follow the tire manufacturer's guide?? Is there a weight/pressure chart for a given make/model/size of tire online? I'm positive you aren't talking about the max pressure rating (for max load) on the side of the tire?"

The load rating of on every tire is designated by a number. Can you show me where to find a chart that shows a list of letters that designate a 'load rating' for each letter ? All I can find is that the letter designates sidewall construction (plies). I understand that the sidewall construction (plies) affects the load carrying capacity of a tire but I can't understand how one can get a 'load range' or psi rating from how the sidewall is constructed.

I quoted this from Tire Direct.com. I didn't make it up to be "mostly right". . . ."The last letter in a standard tire size indicates the number of layers used in the construction of the tire. If there is no letter, the tire has the standard 4 plies. A "C" indicates 6 plies, a "D" indicates 8 plies, and an "E" indicates 10 plies. The higher the number of plies in a tire, the stronger the tire is and the more air pressure the tire can safely hold. Higher ply tires require more air pressure to maintain proper wear. That pressure seems to vary from manufacturer to manufacturer and tire construction to tire." http://www.discounttiredirect.com/direc ... dewall.jsp

As a side note, I run my tires just below 90% of max pressure and my tires aren't wearing more in the center. I guess every tire is different

[bartonmd]

That's exactly what I'm saying! You can't get a psi rating from the size of the tire, or from the load range alone! It all plays in together with the weight the tires are carrying. You're saying that the 90% of max pressure thing is good on the same 285/75-16 tires on a 7k# 1-ton diesel and on a 3500# Jeep... That is just not the case.

I asked about the chart because nobody puts out a chart like that, as far as I know, and that's the only way to get the correct pressure for a given tire under a given load.

If you'll recall, I wasn't the one going by ply rating as a sole rating for pressure. I don't know why you keep trying to argue this with me? Ply rating does matter, though... The stronger the sidewalls, the more weight they support, and the higher the pressure required for even wear... This only applies to stock size, though, if you're comparing to stock pressures... If you go to a different size than stock, you need a new baseline.

By the way, the tires on our TB didn't start showing irregular wear from overinflation until the tread was about half gone... How much of your tread is used to know that your pressure is right?

The "90%" thing from their website, I will flat guarantee, is because there is no across the board right answer that doesn't take into account the the weight the tires are carrying, and it's costing them a ton of money telling people that on the phone... We do stuff like this all the time...

Mike

[bobbyblaze]

I wasn't directing the ply rating thing at you. Sorry if you felt that way. Read my first post again. All I was trying to do is put out some helpful info i've collected during my tire research.

I never avctually wrote that there was some kind of pressure chart. Just said i'd follow the manufacturers guide. Hankook's guideline just happens to be 90% of max pressure. I totally agree on the pressure being relavant to your load weight. I hate when I get new tires mounted and the shop inflates it to the vehicle door jamb sticker without checking wether or not these larger tires are actually the size next to the psi rating they just read.

My tires still look almost new. These things are wearing great. I didn't measure the depth at different parts of the tread when I mounted them so I can't say id there is any extra wear not noticeable to my eye. Now that you brought it up, I wish I had measured them in the beginning. That would be interesting to track during the life of the tire. I want to upgrade to a set of 32x11.5" MT's anyway so I will probably run these tires for another year before I move up the tire food chain.

[bartonmd]

I know your first post wasn't to me... It's fine.

I know you didn't say there was a pressure chart... I asked if you found one, because that would be the only mfg data that would be correct... Any general data like the 90% rule is strictly to have SOMETHING out there, to free up thier tech support lines and save them money...

Mike

[OregTrailBlazin]

Most of the tires guys I talk to refer to the letters as "Load Range".. Each letter that represents the amount of sidewall layers, also represents a certain load range between those. The more layers the higher the rating and the stiffer the sidewall is. I don't know the exact numbers, but I do know, that if you have a tire that says "70lbs max PSI cold" Doesn't mean you have to run it at that. Mine call for 65LBS but if I run them at that under my TB they contact only in the center with about as much traction as a bicycle!! I run them at about 35-38PSI and often have to put more air in them after I get it back from the tire shop. But When I had those same tires on my old Superduty, I had to run them at 55PSI to get even wear.


In the off road would, they refer to the letters because its a better representation of how stiff the sidewall will be and how much flex the tire will give.

Not trying to piss on anyone's shoe's here... This forum sure seems on edge lately.. I find it hard to bite my tongue on some of the forums I have to be on for work, allot of time I'll write a really nice, long response, save it for an hour, and re-read to find out I sounded like a smart ass, or a bitter punk.. Not saying it pertains to anyone in here, just experience!!

[Trail X]

I find it hard to bite my tongue on some of the forums I have to be on for work, allot of time I'll write a really nice, long response, save it for an hour, and re-read to find out I sounded like a smart ass, or a bitter punk.. Not saying it pertains to anyone in here, just experience!!

You always seem to come at things from a good angle Johnny.

[Zero]

Ok so the vibration is still getting worse. We have tried every rotation possible and nothing really helps.

the front tires are feathered. We have even tried running the tires at different psi. The lower I go the worse it seems to get.

SO I think I am at a loss here guys. Sounds like I am just gona have to sell them, at least 3 of the 5 tires are still good. I def. wont ever be getting another set of these tires. I was also told that the cupping issue seems to be worse on a truck that does not have a solid front axle.

I hope I can figure out some way to get this figured out before Tecore, because I cant drive 7 hrs to virginia with the shakes.

i can get the goodyear duratracs for around $240 CAD each, mickey thompson ATZ $260, MTR $270+.

Maybe I will buy 1 new MTR and put my spare that has never seen pavement on. At least then I can replace the 2 feathered tires with 2 new ones. And try to sell the set after tecore.

[Trail X]

[MrSmithsTB]

Any play in your front suspension components? Even with a good alignment, if something is moving a little more than it should it could cause your issues..

[Zero]

No play in anything. My boss and I check everything. A guy with a local jeep club said maybe it was driveline vibration too? but the u joints r fine, so is the trany mount. Ill get pics up soon.

[HARDTRAILZ]

MTR's...Nuff said. they cup badly. Always have and proven once again...They still do.

[Zero]

There was a guy that had it soo bad that Goodyear gave him 2 new tires. Either way, Im gona try something else next time.

[HARDTRAILZ]

There was a guy that had it soo bad that Goodyear gave him 2 new tires. Either way, Im gona try something else next time.

Nice to see them stepping up and making good, but you would think that since they have had this issue since they released the tires, they might just fix it.

You mentioned Duratracs, I like them, but have never seena set worn out, so I would be interested to see what the second half of the tread wear is like. Up to half wear I have heard no real complaints. the Mickey's have proven themselves over and over and seem to just be a solid contender.

Hopefully you get something worked out.

[KE7WOX]

Watch out for using the door sticker. People with the late 90s Exploders followed that. Some didn't survive to tell the story.

[irishboy02]

Wait, you have MTRs w/ kevlar? Thats your problem right there...

Side note: whens the last time you got them balanced