Tire rolling over

[mla163]

Seriously. No way your 225s on a 7.5" wheel are rolling over. Stock class autocross guys are running wider tires on 7" wheels with no issues. Not just this car. All cars.

[CSG Mike]

255 on a 8.5"

Check out that deflection... you can see rim against background.

[smbstyle]

Nice, a Lakeland guy! I've got a SWP BRZ, stock except for the 5Axis spoiler, and am in the County Line Rd / Shepherd Rd area on the south side.

[Big-B]

Originally Posted by smbstyle

Nice, a Lakeland guy! I've got a SWP BRZ, stock except for the 5Axis spoiler, and am in the County Line Rd / Shepherd Rd area on the south side.

I've seen you a couple times, I live off Shepherd Rd. There's also a black one in the area I've seen once.

[Big-B]

Originally Posted by CSG Mike

Sorry, please let me know if I need to clarify... I was up till like 2AM last night studying datalogs, and was at my day job by 7AM this morning.

No need to clarify, understand you perfectly. Tire too wide for wheel / wheel too narrow for tire. I'm still going to switch that tire out because I'm not getting it on the other side. But it is definitely rolling over, I know what it feels like and I know what it looks like.

[mike the snake]

It could possibly be your alignment. If that wheel has positive camber it would help make the tire roll under.

[mla163]

Edit...

Mike, I respect your opinion. But, that picture shows a race car with race tires on a 18" or 19" rim. I see it as a different condition for the OP with a square setup on daily driven passenger tires and 17" wheels.

Maybe you're right. But I've seen plenty of autocross cars run much wider tires in much narrower wheels and I've never seen any scratched rims from rubbing on pavement.

[Anthony]

@CSG Mike, what do you think would be the optimal tire width on a 7.5" wheel to put the most rubber on the ground with no (or almost no) chance of something like this happening? And while we're on the subject, an 8" wheel, since that's what I have. Thanks!

[ZDan]

I would lay the blame more on the tire sidewall being too compliant than "tire too wide for wheel". 225/45-17 on 7.5" width is a perfectly cromulent fitment. Running a narrower tire width isn't necessarily the greatest solution. A 205/50-17 might not roll over as much, but you would likely lose ultimate cornering grip. And of course wheels will be more susceptible to damage from curbs/potholes/etc.

I wouldn't bother going above 36psi cold, that's a bit much, really. I wouldn't worry too much about it, just get stiffer-sidewall tires next time (check tire tests, customer survey results, and customer reviews on Tire Rack's website).

[smbstyle]

Originally Posted by Big-B

I've seen you a couple times, I live off Shepherd Rd. There's also a black one in the area I've seen once.

Yeah theres a black one with green wheels and lowered I've seen around. Too funny! Do you have any plans on bringing it down to Sebring or another track in the area? I'll be down there in August with Chin.

[neurokinetik]

Originally Posted by mla163

Maybe you're right. But I've seen plenty of autocross cars run much wider tires in much narrower wheels and I've never seen any scratched rims from rubbing on pavement.

Typically in those scenarios, people are not running street tires with floppy sidewalls. The Hoosier A6/R6 Kumho V710 and Hankook Z212 all have VERY stiff sidewalls and will tolerate a much narrower rim.

[CSG Mike]

Originally Posted by Anthony

@CSG Mike, what do you think would be the optimal tire width on a 7.5" wheel to put the most rubber on the ground with no (or almost no) chance of something like this happening? And while we're on the subject, an 8" wheel, since that's what I have. Thanks!

It's really the tire more than the size. High performance tires tend to have stiffer sidewalls that can handle more load, so that the rollover doesn't happen.

Originally Posted by mla163

Edit...

Mike, I respect your opinion. But, that picture shows a race car with race tires on a 18" or 19" rim. I see it as a different condition for the OP with a square setup on daily driven passenger tires and 17" wheels.

Maybe you're right. But I've seen plenty of autocross cars run much wider tires in much narrower wheels and I've never seen any scratched rims from rubbing on pavement.

That's actually my personal s2k, on 17" rims with street tires that I daily drive on The rims look bigger because they fill up the wheel well due to compression from lateral load from cornering (look at the body roll... front bumper vs ground is the easiest way to tell). Here's another angle: Oh, yeah, the surface was a bit damp too

[Anthony]

Originally Posted by CSG Mike

It's really the tire more than the size. High performance tires tend to have stiffer sidewalls that can handle more load, so that the rollover doesn't happen.

That does make sense. I guess I'll have to research it next time I need to buy tires. I've been thinking about going with Yokohama AO48's or Toyo R888's next. No clue about sidewall strength on those tires though. Thanks!

[kster1]

Originally Posted by Anthony

That does make sense. I guess I'll have to research it next time I need to buy tires. I've been thinking about going with Yokohama AO48's or Toyo R888's next. No clue about sidewall strength on those tires though. Thanks!

I ran one set of R888s on my old RX-8 just to try them out. They have stiff sidewalls and are fast when new; the problem with these tires is they get heat cycled to death pretty quick. For the BRZ, I am back to the old reliable RA-1 which seem to last forever (I need a set of tires to last a good number of HPDEs).