[Baddawg53]

I've got irregular wear on my front tires, showing excess caster. Knowing this is not adjustable, I'm curious how it would get out of whack. I do have the BMR lowering springs on right now, will be switching to a coilovers setup shortly.

Has anyone had similar issues seeing signs of caster wear on their tires? Any suggestions on fixing this?

[Vtor_ZL1]

https://www.racingjunk.com/news/wp-c.../08/align3.jpg


Front cradle does have some "adjustment" how far out of spec is it ?

[Baddawg53]

I can't remember exactly, seem to recall it was half a degree out of spec. I was surprised it was enough to show wear.

[Norm Peterson]

Originally Posted by Baddawg53

I've got irregular wear on my front tires, showing excess caster. Knowing this is not adjustable, I'm curious how it would get out of whack. I do have the BMR lowering springs on right now, will be switching to a coilovers setup shortly.

Has anyone had similar issues seeing signs of caster wear on their tires? Any suggestions on fixing this?

Can you describe this wear?

From the description provided, I don't think that caster is the problem.

When you lower a car, cambers tend to go more negative, and with a front-steer car (steering rack or linkage ahead of the front axle line) lowering also forces a toe change toward "toe out". Bad toe is the real bad guy in most cases; camber can be considerably more negative than "factory preferred" without causing undue amounts of wear if the driver drives the corners somewhat harder and toe is good.


Norm

[Baddawg53]

Originally Posted by Norm Peterson

Can you describe this wear?

From the description provided, I don't think that caster is the problem.

When you lower a car, cambers tend to go more negative, and with a front-steer car (steering rack or linkage ahead of the front axle line) lowering also forces a toe change toward "toe out". Bad toe is the real bad guy in most cases; camber can be considerably more negative than "factory preferred" without causing undue amounts of wear if the driver drives the corners somewhat harder and toe is good.


Norm

The wear pattern is a feathering from back to front on the treads. It's not toe or camber wear that goes across the tire side to side. The alignment shop made me aware of it and said it was not adjustable. Now I'm on my 2nd set of tires since that alignment and both sets have worn this way.

It's definitely caster. I was a mechanic back in the day, and I have done all my own work on this car other than alignment and tires.

[Msquared]

Never heard of such a thing as "caster wear." You're being fed a line of BS. The only way caster could cause wear is if you have significantly more caster on one side than the other, such that it causes a pull and you're always having to correct that. But that would cause wear on one side's tire only, not on both. Feathering from the leading edges of tread blocks to their trailing edges (if I understand your description correctly) is not a matter of alignment at all.

[Camaro_QC]

Originally Posted by Msquared

Never heard of such a thing as "caster wear." You're being fed a line of BS. The only way caster could cause wear is if you have significantly more caster on one side than the other, such that it causes a pull and you're always having to correct that. But that would cause wear on one side's tire only, not on both. Feathering from the leading edges of tread blocks to their trailing edges (if I understand your description correctly) is not a matter of alignment at all.

https://www.tirebuyer.com/education/...affect-driving

[Baddawg53]

I need to get some pictures, I'll do that later tonight.

I guess my reasoning is, all the alignment specs are good except the caster. The wear on the tire does not reflect typical camber or toe wear which is easily identifiable. It also doesn't reflect any signs of worn suspension components, such as the cupping that happens with worn shocks.

It has happened with continental extreme contact tires on my stock SS wheels, and now with the goodyear supercar 3's on my new wheels. Maybe after the coilovers are on this problem will magically disappear.

[Msquared]

Originally Posted by Camaro_QC

https://www.tirebuyer.com/education/...affect-driving

Yes, and that article clearly says that caster alone doesn't cause tire wear: it has to be in combination with bad toe settings or camber settings. It didn't even mention the issue that I already brought up: uneven caster causing a pull, which could result in tire wear, but not the kind the OP is talking about. OTOH, the OP says:

Originally Posted by Baddawg53

all the alignment specs are good except the caster

Ergo, caster is not causing the problem because tow and camber are in spec. He also didn't indicate the car has a pull or uneven caster. He just said the car has either 0.5-degree too much or too little caster. An SS Camaro is spec'd for 7.4-degrees of caster. Half a degree is absolutely nothing, and you could get that much change if the front or rear tire heights are changed from stock. Since caster is an angle around the same axis that the tire rotates on, there is no physics that can explain what "caster wear" would be. Our universe just doesn't work like that. Somebody is telling the OP "caster wear" because they have no other explanation. I just don't want to see him wasting time/money on silly things that won't help.

[Hotwheeltat]

Post a picture of the alignment print out. Caster is not a tire wearing angle.

[Baddawg53]

I don't have the sheet, must have tossed it.

Well if it's not an alignment issue causing a feathering from back to front on the tread block, then it sure would be great to hear a few possible reasons why it's like this.....

[Norm Peterson]

Originally Posted by Baddawg53

The wear pattern is a feathering from back to front on the treads. It's not toe or camber wear that goes across the tire side to side. The alignment shop made me aware of it and said it was not adjustable. Now I'm on my 2nd set of tires since that alignment and both sets have worn this way.

What you're describing here is commonly known as "heel-toe" tire wear, and it's usually due to not rotating your tires in side to side fashion or by flipping them so that the normal rotation direction gets alternated.

Just like bad toe (and hard cornering) can create a sawtooth tread block profile going crosswise to the tread, braking and acceleration traction can do the same thing in the tire's circumferential direction. Caster need not be involved at all.

From a search on "heel-toe tire wear".




Norm

[Baddawg53]

Originally Posted by Norm Peterson

Just like bad toe (and hard cornering) can create a sawtooth tread block profile going crosswise to the tread, braking and acceleration traction can do the same thing in the tire's circumferential direction. Caster need not be involved at all.


Norm

So this is normal wear from driving aggressively? I’m curious if anyone has had similar wear then. These tires have 1200 miles on them, however that does include 4 track days. Novice/low level intermediate level track days fwiw. Maybe I need to rotate between track days to keep the wear even.

[Racerman27410]

Are you lowering your tire pressures for the track sessions? All sorts of bad things happen to tires after a few laps if the pressure gets too high and the rubber overheats.