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YOUR RESEARCHWeird Tread wear
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under-inflated tires combined
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I had the exact same wear pattern on my last set of rear tires and I was told by two separate tire experts that the wear pattern was caused by under-inflated tires combined with the negative camber (I did run the tires at very low pressure for a few weeks after a track day because I failed to re-inflate them afterward).
Leading evidence: 'under-inflated tires combined' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'under-inflated tires combined' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check inside of the other tire side also' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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So, I figured it was the negative camber putting excessive loads on the inside of the tire to the point it simply wore the tread down to the cords.
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Sidewall height isn't why it rubbed though, but especially if not properly inflated, is probably the reason for the bends.
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Suggestion
What is the width of the wheel and what are the offsets.You might want to check the inside of the other tire side also.
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I had the exact same wear pattern on my last set of rear tires and I was told by two separate tire experts that the wear pattern was caused by under-inflated tires combined with the negative camber (I did run the tires at very low pressure for a few weeks after a track day because I failed to re-inflate them afterward).
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under-inflated tires combined
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
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Reported fixes
Read evidence and context
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0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
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Reported cause
I had the exact same wear pattern on my last set of rear tires and I was told by two separate tire experts that the wear pattern was caused by under-inflated tires combined with the negative camber (I did run the tires at very low pressure for a few weeks after a track day because I failed to re-inflate them afterward).
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Hi All,
I am running 315/25 19's rears on a wide lip rim. Yesterday I had a flat tire and had to put the spare on.
The tire had an interesting tread wear pattern on the extreme inside edge and there was a small gash where it finally gave out. This is the right rear tire. Also, I discovered that the rim was a little bent on the inside.
I am attaching a picture of the tire where u can see the treat wear and the gash(right below my friend's hand). What could possible cause this? The rest of the inside does not look worn out at all. Is the tire rubbing against something? Maybe the rims are too big and I need spacers?
all in all this tire lasted 8700 miles(Conti sport contact 2's)
Also attaching a regular pic of the car so you can see the rims. The rims stick out a little bit. Do I go with 325/30's?
-Manil
Your tire is definitely making contact with something on the car that it shouldn't . I would check the other side ASAP, wouldn't be surprised to see the exact same thing over there. You can add a small spacer to clear the issue but then need to be careful with the tire touching the outside fender lip.
The pic is a little blury but it appears that the entire inside of the tire has been rubbed/worn down to the cord. You could be right that the wheels are too wide. What is the width of the wheel and what are the offsets.You might want to check the inside of the other tire side also. Is it pissible to post a clearer pic?
Not sure, but that could be the result of too much negative camber...you may need a four wheel alignment.....I went thru a set of rears in 4k miles b/c of too much camber...had a similar result on the rear insides....not sure if it was that much though...but I did have the belt showing all the way around.
Good luck!
J
WHAT A GUY!!! Man I tell you, this type of posting makes me smile, knowing there are nice people who are willing to help others out... WTG!!
You are an inspiration today for me!
Not to discouont the "friend" in the passanger seat as a "good guy" too...
"Hey, hold this wheel and tire on your lap for me...."
I hope you bought him a lunch and a beer for that one!
The normal negative camber on the rears will wear out the insides much faster than the outside tread. But you seem to be running extremely wide tires on a car that was not designed around a 19 inch rim, much less one that wide. You may be running into other issues simply because of that.
Thank you for the responses. There was no way of transporting the huge tire back after putting on the spare. I am lucky I was riding with my friend who helped carry it on his lap .
I am sorry I do not have a clearer pic. I drove the car to European performance and dropped it there.
I never heard any rubbing noise..I have fabspeeds on but they are not that loud.
I am guessing that there was some rubbing going on along with the camber issue. Not sure how wide the rim is....the tire on it was a 315 and even that did not cover the entire rim.
Dell...I know we were talking not too long ago and you did comment that I need bigger tires to cover the rim.
I will decide on Monday if I should spend the $$ to get 2 new rears and get the rim repaired etc or go back to stock C4s rims. I have Bilsteins on and the car has been lowered.....I am hoping I can still have those bilsteins on and increase the height if I go the stock rim route....
hmmmmm....I'm still sticking with the negative camber theory. If there was rubbing, I don't think the wear would be so consistent and even....if both tires are doing that, it sounds like the camber is the culprit.
J
The rim is around 13 inch wide. Could not measure accurately as the plier like scale that they had only went to 11 inches.
Update : There was no rubbing so JBRipps was right on. Infact my mechanic says that it can even take a 325 wide tire and still be good. The tread wear is because of the camber setting and the other rear tire shows it as well. It was the same mechanic who aligned and balanced the car last time....does camber setting drift with time? Or did he do a bad job to begin with?
My decision : The rims are bent...the rears more than the fronts. It is gonna cost me about 200 - 250 per rim to get them in top shape again. That combined to with the rubber on the 2 rears and alignment etc etc is a little more than I would like to spend currently. Also, I am not confident that I will not bend those rims again on these NC roads within 2 months. I think those rims are more applicable to a track setting than for 100% street use.
I am going back to my stock c4S rims. Still plan to keep the car lowered as I have the Pss9's on.
Manil, that's a good decision to go back to the stock wheels.
FYI....the wheels you have on right now are NOT anywhere close to a track wheel and actually quite the opposite. They are pure street bling and nothing more. They are beautiful street bling though
Desidon....yes, the rubber can be so pricey on the larger tires! Also, I would suggest getting the 4 wheel alignment AFTER you get the new wheels and tires on. If you don't use your current wrench for that job, I would use the dealership (one of the only things I will let them do). They are more pricey, sometimes around 300 bucks, but they do the best job IMO. Make sure whoever does it knows what they are doing. Since I had my alignment, maybe 8 or 9 k ago, zero wear issues.
Good luck!
J
This same thing happened on my turbo. I thought something was rubbing the inside of the tire causing it look shredded. Well, after looking 2 different times, there was nothing there!
So, I figured it was the negative camber putting excessive loads on the inside of the tire to the point it simply wore the tread down to the cords.
I put on PS's and voila, no problems since.
Also consider that a 315-25-19 has a very short sidewall to begin with. A 911 carries 60% (or more) of its weight on the rear.. and even more forces when cornering. A rear 911 tire, quite simply put, is ABUSED
The short sidewall, ride-height, wieghts/forces, and camber all contribute to wearing out the inside edge of the tire as you found out.
Similarly, a friend had a 3.6 964T. He was running a 295-xx-18.. turns out, the 295 couldn't handle the abuse as well as a slightly taller sidewalled, but narrower, 285 width tire.
sure seems to be an abrupt change on that edge for it to be a camber issue.
Looks a lot more like it was rubbing... severely.
Excessive camber would usually have a wider path of destruction
What did the other tire look like?
Man, learn something new.... I would not have guessed that one. Makes sense when I read the reasons, but I would have been looking for the rub.....
Well there ya have it........... the Porsche engineers thought it thru, we second guess them and end up with torn up tires.... (boy the stock wheels I just put on like like cr*p!, sure like the wider ones!)
GL w/ the stocks and a replacement set when the funds free up to get them.... bling or not!!
By the math I know for this, sidewall height of 315/25 is roughly equivalent to 265/30 or 225/35 (a little under 80mm in most). With 19s, to maintain stock rolling diameter, you're going to theoretically lose 12-13mm of sidewall compared to 18s. However, the stock (at least on turbo) 295/30 18s sidewall is 88mm. In reality there's about a 8-10mm difference (new tire to new tire PS to PS2 in my experience). Sidewall height isn't why it rubbed though, but especially if not properly inflated, is probably the reason for the bends. Doesn't matter if it' 996 or 997, all the 19s get bent.
13 inches is WIDE! The previous alignment shop could have botched your camber settings, which depending on your offsets and the new wheel dimensions could have been difficult for him to optimally configure. It's also possible that whenever you bent that wheel something happened to cause either immediate or gradual change in the camber. Glad you figured it out, good luck!
Ok got my car back today after going to stock rims. I am getting my bent rims "repaired" at this other wheel shop and will be storing them for now. Posting before and after pics....need your feedback on what everyone thinks of the current look with the stock rims and still keeping the car lowered.
Manil
I like the stock rims and I like the lowered look. Even from the side view, it is evident that the rear wheels don't stick out as for as the other wheels.
European performance for changing the wheels out/alignment etc.
Hubcap heaven for rim work. In the future I think I will go to Hubcap heaven for all wheel/tire/suspension/alignment work.
I had the exact same wear pattern on my last set of rear tires and I was told by two separate tire experts that the wear pattern was caused by under-inflated tires combined with the negative camber (I did run the tires at very low pressure for a few weeks after a track day because I failed to re-inflate them afterward). Personally, I'm not sure if they were right or not, but I'm not nearly the expert they are and my replacement set of tires has not shown this wear pattern.
