by "Textured Soy Protein" (texturedsoyprotein)
Published 10/30/2017 at 13:52
by "Textured Soy Protein" (texturedsoyprotein)
Published 10/30/2017 at 13:52
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STARS: 0
My car has some rather aggressive alignment specs, based on my sleuthing around BMW forums. But I have an annoying front end vibration, and when I went to Discount Tire to have my tires re-balanced, they said they couldn’t do it because the front tires’ inside edge was totally worn down. Doh!
First things first: yes I know, forums are more like guidelines than rules, and I probably should not be running -2.25 degrees of camber and a little bit of toe in on the front of a street car with a McPherson strut front suspension. But the stupid track rat BMW forum people were like, “you should run at least -1.75 degrees in front for good grip, and more is better!” This was a bad decision on my part.
I have Kumho PS91 summer tires, and while I’ve been very happy with their grip, they have a stiff ride and they make a kind of rhythmic wub-wub noise from around 35-50 mph that’s particularly irritating. They smooth out on the highway but then once speeds approach 70 mph or higher they introduce a higher-frequency vibration of the whole car. Blech. The uneven wear on the inner edge of the front tires has only made things worse.
UPDATE: Ok, ok, even though it’s damn cold outside and a mini flurry is happening at this very moment, I took a picture of my front tire to compare to what it should look like.
The grooves on the inner tiread blocks are rounded off on the inside edge of the tire. That’s my problem.
Carrying on now...
I’m going to my excellent alignment guy tomorrow who is going to zero out the toe and take the camber to a more reasonable -1.75. That should give decent handling while hopefully not chewing up the inside edge of the tires so badly.
Since the front tires need to be replaced, but the rears are basically fine, I think it’s time to choose a different tire for the front, and then match them when the rears wear out. I’m probably going to switch to the Firestone Firehawk Indy 500 (a.k.a. Bridgestone Potenza RE003), in the hope that they won’t have the same noise issues as the Kumho PS91. I bought the PS91 like a month before the Indy 500 came out, to immediate acclaim, and ever since then I’ve kinda regretted choosing the Kumhos, especially with the annoying noise.
Since I usually swap on my winter tires the weekend before Thanksgiving, there’s no good reason to spend money now on fresh front summer tires. It would be objectively stupid to spend $385 now for less than 3 weeks of hopefully-noise-free driving before my winter tires go on, and then stack those $385 worth of practically new tires up in the corner of my garage. And yet, I find myself thinking about getting fresh front summer tires. The rational part of me is like, “dude, no, just wait til spring!” but I am a thoroughly irrational person when it comes to spending money on car stuff.
I hope that by posting here, I’ll stop myself from making a bad decision. Except I’m sure all of you will encourage me to spend the money now, like the bunch of bad influencers that you are.
Patience. Breathe. The winter tires don’t have this noise issue. Let it be. Save the money until spring time. Woosah.
"Stapleface" (patrickgruden)
10/30/2017 at 13:56, STARS: 2
I dunno. If you know you need tires anyway, I see no reason to wait. I’d rather drive around on good tires versus stretching the poorly worn tires for another few weeks. Or, if you don’t want to spend the money, just put the winters on a couple of weeks early.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 13:58, STARS: 0
It’s only the inner-most 1/8 of the width of the tire that’s chewed up. The other 7/8 is totally fine. They’re not unsafe, only annoying. (The pic isn’t my tires.)
"rillweid - Now with more TRD and less TDI" (rillweid)
10/30/2017 at 14:01, STARS: 3
If it makes you feel better someone in my parking lot has been driving like this for months.
"benjrblant" (benjblant)
10/30/2017 at 14:02, STARS: 2
I know the photo isn’t yours, but damn. Hard to think past that image.
"PartyPooper2012" (PartyPooper2012)
10/30/2017 at 14:02, STARS: 1
Your definition of unsafe is unsafe.
"Steve in Manhattan" (blogenfreude01)
10/30/2017 at 14:08, STARS: 0
Don’t mess around with tires and suspension. They keep your car on the ground (and tires are the only contact point) - you are risking your life.
"Die-Trying" (die-trying)
10/30/2017 at 14:10, STARS: 0
can you have the tires remounted? so that the worn out corner is now on the outside edge? just a dumb idea from a guy who drives on old tires waaay too long.....
"shop-teacher" (shop-teacher)
10/30/2017 at 14:11, STARS: 4
Just put the winters on now and buy new summers in the spring.
"Mercedes Streeter" (smart)
10/30/2017 at 14:13, STARS: 0
I’ve never had a Kumho tyre that I enjoyed.
You probably won’t get much sympathy here, but I drove my smart on bad tyres through last fall into last winter, into this spring, into this summer, then finally swapped out at the beginning of this fall. The treads were good, they just made an awful racket. They were feathered so bad that you could visibly see that the insides of the tyres weren’t even really round. They were like the tyres out of a PS2 era GTA game.
They were cheap Chinese branded tyres that couldn’t handle a smart’s aggressive alignment (which from the factory will wear the insides quicker than the outsides).
I mean, so long as you good tread left (ie, not past the wear bars), you don’t need to replace them now. If you’re looking bald, replace now!!!!
Edit: Looking at your picture, yeah I wouldn’t worry too much. They’ll last a little longer.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 14:19, STARS: 1
I updated the post, now with what my tire actually looks like.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 14:22, STARS: 0
The initial hype on the PS91 was that they were a surprisingly good Michelin Pilot Super Sport knockoff.
My experience with them is that their grip is very good but the refinement just isn’t there.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 14:24, STARS: 1
They’re asymmetric and have to be mounted with the outside edge on the outside. They’re at least not directional so can be rotated side to side, but not front to back since I run staggered sizes.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 14:24, STARS: 0
See the updated post with a pic of my tire for context.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 14:24, STARS: 0
See the updated post with a pic of my tire for context.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 14:25, STARS: 0
That’s also an option, since today is now the second mini-flurry of the fall so far and the temps are starting to get down into the 40s.
"Decay buys too many beaters" (decay)
10/30/2017 at 14:26, STARS: 0
Not universal I know, but I find toe to be a LOT more relevant to tire wear than camber.
I run -3.5 per side front on a street car with zero front toe and get even wear. Rear is set up at -1.7 per side with a little toe out.
"davesaddiction @ opposite-lock.com" (davesaddiction)
10/30/2017 at 14:32, STARS: 0
“This was a bad decision on my part.”
BMW factory alignment is already aggressive before going further. I’ve been there...
"PartyPooper2012" (PartyPooper2012)
10/30/2017 at 14:32, STARS: 0
phew. Don’t scare us like that. the mere existence of the original photo is an indication that there are in fact people out there who think THOSE tires are still safe.
p.s. I took my gx470 in for alignment. They claim everything is fine, but inside of my tires are wearing out prematurely. They claimed my alignment was off by about a degree and they adjusted it... allegedly.
Fuck... I can’t even put in words how much I hate leaving my car with someone and trusting them to do the required work. I never know if they did the work, or if they just took my money and held my car for a day or two...
"Chris_K_F drives an FR-Slow" (chriskf)
10/30/2017 at 14:36, STARS: 0
I agree with shop-teacher.
For new summers next year check out the Conti ExtremeContact Sport, they’re supposed to be awesome.
I’m guessing your wear issue had more to do with the toe in than the negative camber. How much toe in were you running? It’s interesting, because Toyobaru folks routinely run -2.5
°
to over -3
°
of camber for autox/track/dd and don’t have any wear issues.
"shop-teacher" (shop-teacher)
10/30/2017 at 14:37, STARS: 0
It’s definitely been winter tire temps in Chicago this week. I imagine more so even up by you.
"Not a Sunburst Miata" (moezsayani)
10/30/2017 at 14:41, STARS: 1
On the BRZ I’m running -2.5 camber in the front and zero toe, rears are -2 with a tiny amount of toe in, no strange wear patterns here.
"Rico" (ricorich)
10/30/2017 at 14:43, STARS: 0
Next time definitely use your own picture for a post like this. I came in here to rip your Oppo card out of your hands thinking you were actually driving around on tires that worn out.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 14:50, STARS: 0
Yeah, toe is definitely part of the problem. The specs say 0.07° to 0.40° total toe in for the front, 0.20° to 0.40° rear. I’m at 0.30° right now on both axles. It’s not a lot but I have a feeling it’s contributing to the tire wear issue.
What kind of street car are you talking about with the -3.5°? I know that generally wishbone/multilink suspensions do a better job than McPherson struts at locating the wheels at higher negative camber settings.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 14:51, STARS: 0
The (admittedly small and not very visible) caption on the top pic says...
“These aren’t my tires, I just liked the picture on google image search.”
"PartyPooper2012" (PartyPooper2012)
10/30/2017 at 14:53, STARS: 0
Yeah...well... i read that after I posted and I was too lazy to edit.. so there you go. Miscommunication. I think some wars started based on miscommunications.
I know for a fact, world war 5 was started by my wife when I said I’ll take trash out later and she thought I said immediately.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 14:54, STARS: 0
This is what I get for thinking people would notice the caption under the picture!
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 15:02, STARS: 1
0.30° total toe in on the front. Factory spec is 0.07° to 0.40°.
I thought about the Contis. Compared to the Indy 500 they’re $36/each more in front and $60/each more in rear. From the Tire Rack tests they do look like a pretty solid upgrade in wet performance.
Another benefit of waiting until springtime is I can see what kind of anecdotal reviews on the Contis trickle out between now and March, at least from folks in warmer climates.
"Jayhawk Jake" (jayhawkjake)
10/30/2017 at 15:12, STARS: 0
Better than what happened to the PS91's I had. Half of one of the center treadblocks sheared off completely.
"Jayhawk Jake" (jayhawkjake)
10/30/2017 at 15:14, STARS: 1
You can swap the LF tire to the RF wheel and vice versa. Might have to go to a non-franchise tire shop for them to do it.
Source: literally the only way I can actually afford to autocross.
EDIT: Doi, asymmetric. I read that as directional. Nevermind...
"Decay buys too many beaters" (decay)
10/30/2017 at 15:26, STARS: 0
It’s an FR-S, so McPherson struts. Factory was zero camber and I wore the outside edges out before the insides showed wear and was dealing with a lot of understeer. Stepped it up to 1.5, got a little better, but was still rolling over the outside edges during heavy cornering and wearing inside edge at a lower rate. Stepped it up to the maximum available at the strut top (still have about another degree available at the lower mount and the wear evened out. This also gave it a good bias toward oversteer, understeer scares the hell out of
I do not do any highway though and the roads I do drive are pretty curvy.
"JawzX2, Boost Addict. 1.6t, 2.7tt, 4.2t" (jawzx2)
10/30/2017 at 15:27, STARS: 1
agreed, my Alfa 164-S had stock camber of -2.5°. In a FWD car. But the near neutral toe meant wear was not that bad.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 15:32, STARS: 0
Most of my driving is in a straight line with selected turns. I have to go looking for twisties.
"AestheticsInMotion" (aestheticsinmotion)
10/30/2017 at 15:41, STARS: 0
Those tires look fine. Wait it out through the winter? I can’t imagine not doing all four corners at once if you’re going with summer tires
Totally understand the forum “problem” though. I’ve had to ask myself, “do I really need 200tw tires that are 4 inches wider than stock for my street car?”
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 15:50, STARS: 0
It’s unfortunate that the PS91 is shaping up to be kind of a dud tire...and that I bought them. ¯\_()_/¯
I don’t want to spend Pilot Sport 4S money, and the Continental ExtremeContact Sport is getting close to that ballpark.
In my sizes, the more-appealing choices that are similar price to the PS91 are the Firehawk Indy 500 and Hankook V12 evo2. From what I’d read about the Hankooks it seems like more people call them out for being kinda noisy and having poor tread life.
I’d like to at least get one more season out of the rear PS91s before I junk them though, they have plenty of life left and without the weird inner edge wear they (hopefully) aren’t the source of the vibration.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 15:54, STARS: 0
Well of course the logical course of action is to wait until spring since I’m putting my winter tires on in no more than 20 days anyway. But the stupid car guy part of me is like, “with that more reasonable alignment, you want to enjoy some summer tires now , don’t you?”
"Jayhawk Jake" (jayhawkjake)
10/30/2017 at 16:01, STARS: 0
IMO standard street tires are all basically garbage, and no one really utilizes them to their fullest grip potential so spending big bucks on them is pointless. I realize AutoX is different than the street, but I drove a Focus RS on PSS and I was completely underwhelmed. Steering response was better than I’d expect from a typical all season but ultimate grip was poor.
If you really want performance get a 200TW performance tire. I probably wouldn’t recommend RE-71Rs for anything other than autox, they heat up real fast, but I’ve heard that Rivals are a little better on the road. Hankook Ventus RS4s are probably pretty good for street use too, RS3s were great.
I’m running BFG Comp 2 A/S for daily use. They seem decent enough. Honestly I have more fun street driving the skinnier Comp 2's than I do the wide RE-71Rs I use for autox. The RE71s react extremely well and grip like crazy, but then I’m never close to their limit if I’m being safe. They’re also really loud, follow every imperfection in the road, and have super stiff sidewalls killing ride comfort. The BFG’s are a sight better than the Eagle F1s my ecoboost had while still allowing for some playful livelyness.
That being said, Indy 500's are pretty cheap IIRC, might not hurt to try as a summer. I want to say I generally see them at Tires Plus for like $170 each and Buy 3 get 1 Free, which is amazingly cheap for my size.
"Steve in Manhattan" (blogenfreude01)
10/30/2017 at 16:04, STARS: 0
Yeah, inside wear bars are right on the edge ... just don’t take any chances.
"JGrabowMSt" (jgrabowmst)
10/30/2017 at 16:46, STARS: 0
Outside edge of the HEMIWagon front tires are wearing super fast, need to do something about that soon, including not cornering quite so fast on public roads.
It should be at zero toe, but I think thats the problem, it should have toe to account for the aggressive camber.
"GTRZILLAR32-Now saving for Godzilla and a condo" (jackolson)
10/30/2017 at 17:00, STARS: 0
PS91’s suck... I almost put them on my M3 and my mechanic had a set on his to try them and he hated them. I eventually went with the new Continental ExtremeContact Sports and loved them.
"uofime-2" (uofime-2)
10/30/2017 at 17:18, STARS: 1
it isn’t the camber that killed those, its the toe.
source: I have -2.5 deg front and -2.0deg rear camber on my car (but zero toe). R-S4s with 400miles on the track and 10k on the street and they’re still nice and even.
why did you toe-in in the first place?
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 18:00, STARS: 0
No 200TW or all-season tires for me. I want something that will hold up to the heat from repeated back road shenanigans but is still somewhat civilized commuting around town.
I had a set of Hankook RS2 on my Miata, and those were fun but not what I want on my BMW.
I had a set of Continental EC DW on my Mazdaspeed 6, and while they were very good in the wet, and nice and smooth and quiet for a summer tire, their steering response was mushy and they went greasy on repeated back road bombings.
My ideal tire is the refinement of the Conti DW but more heat capacity & steering bite.
The PS91, in theory, was exactly what I wanted. They’ve held up to sustained back road bombing, they grip in the wet, they have good steering response. They’re a tad clompier than I’d like, but not awful. The problem is the noise/vibration.
The more I read reviews the more the new Conti EC Sport appeals to me. I didn’t realize there were already reviews out on it. The EC Sport appears to have some of that same noise/comfort advantage as the DW but improves the negatives, so that may move them up my list.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 18:06, STARS: 0
I went with a little toe in to reduce twitchiness. My B&G springs have rates more biased to the rear than stock, and I also have an M3 convertible rear sway bar. Even though I have staggered tires with bigass 275s in back, I was thinking it would make the car not too eager to change direction. But there’s plenty of tire grip on both ends of the car, especially the rear. If anything I could go with even more rearward bias. So I’m getting rid of the toe. Although technically the minimum toe in setting for the rear is 0.20, not 0.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 18:08, STARS: 0
I went with the PS91 right before the Indy 500 came out, and then the EC Sport. EC Sport is definitely on my radar now.
I had a set of Conti DW on my old Mazdaspeed 6. I liked the smoothness & quietness but the steering response was a little mushy and they went greasy a little too quickly on back roads. Have you given the EC Sports a proper thrashing?
"AM3R, lost another burner" (am3r17)
10/30/2017 at 18:38, STARS: 0
I have the Indy 500's on my 335i. Surprisingly good wet grip, good dry grip, less noise than the stock runflats and also more comortable. Good steering feel as well. Feel free to ask any questions. More remarkably, got them in staggered 255/35 and 225/40 for under $400 shipped.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 18:40, STARS: 0
I’m not going to get that price in 235/35-19 + 275/30-19 but they’re still more affordable than even the current Kumho PS91 I have on my car.
Do you have any issues with flat-spotting or vibration?
"GTRZILLAR32-Now saving for Godzilla and a condo" (jackolson)
10/30/2017 at 19:43, STARS: 0
Oh yeah beat the hell out of them for about 3k miles before I sold the car. I never felt any mushiness or hesitation on turn-in that was confidence degrading, but there was a little which I assumed was normal for an 18-inch tire (I had the OEM 225/35/19F before). On some really spirited drives I never had the tires get greasy and they put the power down great. Fuck , I miss that car.
"Textured Soy Protein" (texturedsoyprotein)
10/30/2017 at 20:34, STARS: 0
Sounds like these might be my move. If I can get some more comfortlike the Conti DW provided that would be a plus, both for myself commuting around on crappy Wisconsin roads and so I get a few less complaints when my wife rides in the car. The cost won’t be *too* bad if I get the fronts in the spring and try to get at least another summer out of my rear PS91. The back of the car handles bumps better than the front and the rear tires have plenty of life left in them.
"AM3R, lost another burner" (am3r17)
10/31/2017 at 00:00, STARS: 0
No vibrations, had my wheels/tires put on by my BMW specialist shop who did a great job balancing them and aligning the car after. I haven’t noticed flatspotting, the car lives outside but the most it’s been parked without being driven is maybe 2 days. My gym is only about 1 mile from my house so I do short drives all the time, and I would’ve felt flatspotting by now. I do run my PSI a little higher for that good turn in feel though.
also, they run a little narrow, which I kinda like because it allows me to fit an 18x9.5 et25 out back without rubbing. Totally flush fitment with no spacers, and no rubbing at all. With PSS the wheels would have rubbed like crazy.
"uofime-2" (uofime-2)
10/31/2017 at 09:36, STARS: 0
Technically my car is not specified to run zero toe either, but if I ask my dealer alignment tech real nice he’ll do it without complaint.
The camber you have should keep you going straight pretty well. Beemers of old tended to have lots of caster which is also beneficial for stability.
that said once all your changes are done you should still find a safe place to find out what it likes to do at the limit.
"Textured Soy Protein" (texturedsoyprotein)
10/31/2017 at 10:53, STARS: 0
My caster adjustment range with my camber plates that sorta kinda not really let you adjust caster is from +6° to +9°. My front passenger summer tire likes to rub on the front of my fender liner where my oil cooler is mounted, so I keep it at the +6°.
I should point out that my particular BMW is awd, which I think may also have something to do with the excessive inner edge wear.
My alignment guy suggested that the camber and toe both contributed to the wear but recommended at least doing a little bit of toe in still. He said it’s probably best to go with the minimum recommended toe in (0.07° front, 0.20° rear) rather than full zero. The rear is more because I have a slight rub on the trailing edge of the driver’s fender liner so I’m hoping to clean that up.
He also suggested that if I really want to keep from chewing the tires up, don’t bother with a ton of front camber. Since it’s a street car that gets chucked around back roads, might as well go with a milder setting. The reality is my car sees a lot of straight-ahead driving. The roads here aren’t twisty and curvy. Sure, I have a couple roundabouts on my way to work, and I’ll heel-toe the occasional neighborhood and office park entry turn, but really, I have to go find twisties rather than have them present themselves in normal driving.
So, I’m keeping the rear at the -2° camber it’s at right now but the front I’m dialing back to -1.25°. That’s enough to help with cornering but not so much that it’ll chew the front tires.
"uofime-2" (uofime-2)
10/31/2017 at 12:02, STARS: 0
this is from my suspension tech article :
monkeyed with
I’m not saying that this is necessarily what you want. I will say it makes my car very entertaining to drive. I understand your alignment tech wanting to cover himself by following the minimum spec, but I really don’t think you need the front toe in. Camber will not wear tires until you get silly with it, like -4 deg.
It is odd you got so much wear. Stock my car had -.2 deg toe in. It drove around like that for at least 10k miles and It never showed excessive wear. So you’ll probably be fine
stock
"Textured Soy Protein" (texturedsoyprotein)
10/31/2017 at 12:35, STARS: 0
The alignment guy will set the car however I want, including the last alignment. He was making recommendations to help fix the tire wear issue, not covering his ass.
I know it’s certainly possible that other cars have run more negative camber without chewing up the front tires like this, but this is the result on my car. I suppose it’s possible the Kumho PS91 don’t like lots of camber and the problem is specific to the tires, but I didn’t want to test that theory by waiting and seeing if yet more tires get chewed up like this. I needed to do something.
My car doesn’t see the track and I have loads of suspension mods so being a little conservative with the camber isn’t going to suddenly ruin the handling.