I know that lack of rotation will cause cupping but the dart killed the rear tires. They were rotated at 10,000 and have been on the rear about 6,000 miles are both rears are junk cupped pretty severely. So I'm buying new tires. But what else could cause this the tires that were on it are rotational tires so they can only be rotated front to rear and rear to front. Any input or advice is appreciated!!
Rear tire cupping
- Thread starter ram_man
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I thought cupping pointed to struts.
I had a VW that liked to feather/chop the the rear tires; the rear axle had slowly bent over time, leading to toe-in condition. That car really needed frequent tire rotations as a result.
I'd do an alignment to start with, see if the rear is set up properly.
I had a VW that liked to feather/chop the the rear tires; the rear axle had slowly bent over time, leading to toe-in condition. That car really needed frequent tire rotations as a result.
I'd do an alignment to start with, see if the rear is set up properly.
Shocks had caused my cupping problem with a dodge dart. Ed
OP, just to be clear, are you talking cupping or scalloping?
Cupping is where the tire has segments of unusual wear that spans several tread blocks. This is usually caused by worn shocks/struts.
Scalloping is where individual tread blocks wear unevenly, "feathering" in the same sloping pattern. This is usually caused by alignment.
Scott
Cupping is where the tire has segments of unusual wear that spans several tread blocks. This is usually caused by worn shocks/struts.
Scalloping is where individual tread blocks wear unevenly, "feathering" in the same sloping pattern. This is usually caused by alignment.
Scott
FYI ... correct or not ... EVERY tire shop I have ever discussed this type of tire wear with calls it CUPPING ...
Rear tires are often prone to cupping type wear as a result of suspension set-up. Most cars run more negative camber on the rear than the fronts, and usually some toe in on the back wheels as well. The rear tires are always getting dragged across the inner blocks ever so slightly. This set up makes the car more stable and less likely to oversteer ( lose grip in the rear before the front ... ) which is important to car makers for liability reasons. When a car spins, they get sued ...
Much more frequent full ( cross x ) tire rotations, using non-directional tires that can be cross rotated, would likely help with tire life.
Rear tires are often prone to cupping type wear as a result of suspension set-up. Most cars run more negative camber on the rear than the fronts, and usually some toe in on the back wheels as well. The rear tires are always getting dragged across the inner blocks ever so slightly. This set up makes the car more stable and less likely to oversteer ( lose grip in the rear before the front ... ) which is important to car makers for liability reasons. When a car spins, they get sued ...
Much more frequent full ( cross x ) tire rotations, using non-directional tires that can be cross rotated, would likely help with tire life.
Shocks/struts are the usual culprit although weak bushings or worn parts can induce wheel hop with the same effect.
It's pretty easy to see on other vehicles you follow down the road. You see bad alignment, bad tires, bad shocks, and the driver just cruising along without a clue. Just have someone drive your car, follow it with another, and maybe see an issue.
My Focus had an agressive toe-out from the factory to assist with handling. Unfortunately that caused it to burn the insides off of the rear tires. I'd get you alignment checked.
![[Linked Image]](http://cyoum84abk-flywheel.netdna-ssl.com/wp-content/uploads/2016/11/diagonal-tire-cupping.jpg "[Linked Image]")
![[Linked Image]](http://perfectcircletire.com/images/tirewear.png "[Linked Image]")
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Originally Posted by ram_man
The alignment was in spec and good all the sus was tight. I think it's a product of the suspension geometry and I should probably rotate more often. Maybe I should do the shocks? The car has 68k on it.
It is my opinion that the published alignment specs are too wide - by half. Not the target, but the allowable variation from that target value. For good tire wear, the alignment needs to be within the inner half of the tolerance.
Also, my experience says that any camber larger than 1 degree causes wear issues.
The alignment was in spec and good all the sus was tight. I think it's a product of the suspension geometry and I should probably rotate more often. Maybe I should do the shocks? The car has 68k on it.
It is my opinion that the published alignment specs are too wide - by half. Not the target, but the allowable variation from that target value. For good tire wear, the alignment needs to be within the inner half of the tolerance.
Also, my experience says that any camber larger than 1 degree causes wear issues.
Originally Posted by CapriRacer
It is my opinion that the published alignment specs are too wide - by half. Not the target, but the allowable variation from that target value. For good tire wear, the alignment needs to be within the inner half of the tolerance.
Also, my experience says that any camber larger than 1 degree causes wear issues.
Tell that to a flat rate tech who makes very little money doing alignments ... within spec ... good enough. THAT is the problem.
It is my opinion that the published alignment specs are too wide - by half. Not the target, but the allowable variation from that target value. For good tire wear, the alignment needs to be within the inner half of the tolerance.
Also, my experience says that any camber larger than 1 degree causes wear issues.
Tell that to a flat rate tech who makes very little money doing alignments ... within spec ... good enough. THAT is the problem.
My Focus wagon burned through a pair of General Altimax Arctics on the rear in 20k miles. The front tires have 50k on them so far, wearing evenly.
Weak rear springs seemed to be the culprit. The Control Blade rear suspension adds a bit of toe-in during compression, but if the springs are weak, the toe-in is added when not needed, and wears the tires down, New rear springs, shocks and alignment seems to have solved the problem.
Get the rear end checked and aligned properly.
Weak rear springs seemed to be the culprit. The Control Blade rear suspension adds a bit of toe-in during compression, but if the springs are weak, the toe-in is added when not needed, and wears the tires down, New rear springs, shocks and alignment seems to have solved the problem.
Get the rear end checked and aligned properly.
Every FWD car I have ever owned cupped rear tires to some extent. I think it is a combination of a too stiff rear end, to be able to handle a FULL LOAD situation, and alignment specs that are too far off zero camber / toe, for high speed stability. Add too infrequent tire rotations and the tires start to cup ... for the average owner, I'm not sure there is anything you can do about it. For enthusiasts, suspension mods, non-factory alignment specs and OCD frequent tire rotations would probably help.
Originally Posted by Wagonmaster261
My Focus wagon burned through a pair of General Altimax Arctics on the rear in 20k miles. The front tires have 50k on them so far, wearing evenly.
Weak rear springs seemed to be the culprit. The Control Blade rear suspension adds a bit of toe-in during compression, but if the springs are weak, the toe-in is added when not needed, and wears the tires down, New rear springs, shocks and alignment seems to have solved the problem.
Get the rear end checked and aligned properly.
I couldn't get anyone to align the rear of mine because it was in-spec. So I loaded a bunch of weight in the back and had it aligned back into sped. Never had a problem after that.
My Focus wagon burned through a pair of General Altimax Arctics on the rear in 20k miles. The front tires have 50k on them so far, wearing evenly.
Weak rear springs seemed to be the culprit. The Control Blade rear suspension adds a bit of toe-in during compression, but if the springs are weak, the toe-in is added when not needed, and wears the tires down, New rear springs, shocks and alignment seems to have solved the problem.
Get the rear end checked and aligned properly.
I couldn't get anyone to align the rear of mine because it was in-spec. So I loaded a bunch of weight in the back and had it aligned back into sped. Never had a problem after that.
Originally Posted by Miller88
I couldn't get anyone to align the rear of mine because it was in-spec. So I loaded a bunch of weight in the back and had it aligned back into sped. Never had a problem after that.
In-spec on a Focus can still burn the tires off with a quickness. Too wide of a tolerance. I think the recommendation from the Focus forum I visit is setting rear toe to 0. May require extra, adjustable parts.
For my usage, a simple beam axle might be better. Might not handle as well, but would last longer without needing repairs and new tires. Everything else I own has a beam axle in the rear.
I couldn't get anyone to align the rear of mine because it was in-spec. So I loaded a bunch of weight in the back and had it aligned back into sped. Never had a problem after that.
In-spec on a Focus can still burn the tires off with a quickness. Too wide of a tolerance. I think the recommendation from the Focus forum I visit is setting rear toe to 0. May require extra, adjustable parts.
For my usage, a simple beam axle might be better. Might not handle as well, but would last longer without needing repairs and new tires. Everything else I own has a beam axle in the rear.
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