Why the f00k does my sidewall keep bubbling?

[Neb]

I've ran Nitto Neogens and loved them. they stretch great and handled good for the tire.

Also had Fuzion Tires and I liked them a lot.

[Polo Classic]

Ok so this all started on my old set of wheels, I had 19x8.5 with a set of falken fk452 225/35 on them, i noticed after about 5 k my sidewall bubbled on both fronts. I put them on the back and put the good tires up front, which also lasted me about another 5k.So my question to you all is, wtf am i doing wrong?

Is this a result of an impact? or lack of checking tire pressure? or do i officially have the worst luck in the world?

fuck sorry for the book guys... but i appriciate any help.

What tyre pressure are you running. Whats the load index of the tyres and what does the car weight (f/r)

I'd say most likey the 225/35 and 205/40 have a too low load rating for your Audi

(running 235/30-20 FK452's on 9,5x20)

[da_force]

I'll go back a bit...

All in all what do you guys think of T1R's in 205/40 on an 17x8.5 rim?

[geoffafa]

whoa this thread has somewhat derailed, but in a great way.

all this info is great to know. Im gonna look into the nittos (a friend has some 225/35/19 on some 8.5s in his a4. he loves them. Ill also look into the nankangs.

but can anyone give me feedback on the hankook rs2?

[Han]

What I mean by running small, is a 235/45-17 Falken ZE512 stretched on my OEM 17x8's while the Toyo Proxes4's I had in the same size were squared in the same rim. The rolling diameter looked smaller by a cunt hair though.

Although, I know what you mean, it's only a visual appearance. The way the 512s are designed look stretched even on stock wheels and tires. There are extremely minuscule differences in rolling diameter from tire to tire, but it's acceptable. (Nothing that will make or break a "size," since a 225/40/18 is a 225/40/18 mathematically). I have no argument there on the visual point of view, but on a math side, it's all the same.

[JackEatsEmoKids]

Yes, I understand that. However, 40% of 255 is always going to be 102mm.

Width x Aspect Ratio = Section Height
Section Height x 2 = Combined Section Height
Combined Section Height + Wheel Diameter = Tire Diameter

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=7

255 x .4 = 102mm = Section Height
102 x 2 = 204mm = Combined section Height
204mm + 431.8 (17 x 25.4) = 635.8 / 25.4 = 25.0314 inch = Tire Diameter

Falken 512's list a 255/40/17 as a 25.2 Diameter. (A tire that people consider "small")
Falken 452's list a 255/40/17 as a 25.0 Diameter. (A tire that people consider "small")
Falken Azenis RT-615 list a 255/40/17 as a 25.0 Diameter (A tire that people consider "correct"/"big")

Your examples:
Toyo RA1 lists a 255/40/17 as 25.0 Diameter. http://toyotires.com/tire/pattern/proxes-ra1
Toyo TR1 lists a 255/40/17 as a 25.0 Diameter. http://toyotires.com/tire/pattern/proxes-t1r


Those are all measured on a 9" wide wheel by Falken and Toyo.

That's a variance of +/- .2" (.1" top and .1" bottom). That's acceptable, but I cannot see any tire have a +/- .5" variance in measurement...

Again, it's all visual differences. Math and numbers don't change.

What I mean by running small, is a 235/45-17 Falken ZE512 stretched on my OEM 17x8's while the Toyo Proxes4's I had in the same size were squared in the same rim. The rolling diameter looked smaller by a cunt hair though.

[Han]

Technically no.

40 series is means the side wall is 40% of the width of the tire. Since we established that the section width can vary then so does the side wall height.

My 255/40 Toyo RA1s have a greater rolling diameter than the 255/40 Toyo T1Rs I use to have. Its clearly visible because the T1Rs sat about a half inch shorter than the RA1s

Yes, I understand that. However, 40% of 255 is always going to be 102mm.

Width x Aspect Ratio = Section Height
Section Height x 2 = Combined Section Height
Combined Section Height + Wheel Diameter = Tire Diameter

Width x Aspect Ratio = Section Height
Section Height x 2 = Combined Section Height
Combined Section Height + Wheel Diameter = Tire Diameter

Example: 185/60R14 85H or 185/60HR14

185mm x .60=111mm
111mm x 2=222mm
222mm + 355.6mm(14")= 577.6mm or 22.74"

The first number is the width of the tire in millimeters, measured from sidewall to sidewall. To convert to inches, divide by 25.4 In the example above, the width is 185mm or 7.28".

The second number is the aspect ratio. This is a ratio of sidewall height to width. In the example above, the tire is 7.28" wide, multiply that by the aspect ratio to find the height of one sidewall. In this case, 185x0.60=111mm or 7.28"x0.60=4.36".

The last number is the diameter of the wheel in inches.

To figure the outside diameter of a tire, take the sidewall height and multiply by 2,(remember that the diameter is made up of 2 sidewalls, the one above the wheel, and the one below the wheel) and add the diameter of the wheel to get your answer.

http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=7

255 x .4 = 102mm = Section Height
102 x 2 = 204mm = Combined section Height
204mm + 431.8 (17 x 25.4) = 635.8 / 25.4 = 25.0314 inch = Tire Diameter

Falken 512's list a 255/40/17 as a 25.2 Diameter. (A tire that people consider "small")
Falken 452's list a 255/40/17 as a 25.0 Diameter. (A tire that people consider "small")
Falken Azenis RT-615 list a 255/40/17 as a 25.0 Diameter (A tire that people consider "correct"/"big")

Your examples:
Toyo RA1 lists a 255/40/17 as 25.0 Diameter. http://toyotires.com/tire/pattern/proxes-ra1
Toyo TR1 lists a 255/40/17 as a 25.0 Diameter. http://toyotires.com/tire/pattern/proxes-t1r


Those are all measured on a 9" wide wheel by Falken and Toyo.

That's a variance of +/- .2" (.1" top and .1" bottom). That's acceptable, but I cannot see any tire have a +/- .5" variance in measurement... Unless if your measurements are in a completely controlled environment and with static variables and controls, I do not see a logical reason to disprove the tire manufacturer's own findings.

Again, it's all visual differences. Math and numbers don't change.

[Geoff.T]

Right, but section widths are not used to calculate rolling diameters. The overall width is, hence the 205/215/225/etc designation.

http://www.tirerack.com/tires/tiretech/tirespecskey.jsp

AKA: Why I said it's a sidewall design, not actual width (IE: 225) because that stays constant.

Technically no.

40 series is means the side wall is 40% of the width of the tire. Since we established that the section width can vary then so does the side wall height.

My 255/40 Toyo RA1s have a greater rolling diameter than the 255/40 Toyo T1Rs I use to have. Its clearly visible because the T1Rs sat about a half inch shorter than the RA1s

[Han]

Right, but section widths are not used to calculate rolling diameters. The overall width is, hence the 205/215/225/etc designation.

Section Width

A tire's section width (also called "cross section width") is the measurement of the tire's width from its inner sidewall to its outer sidewall (excluding any protective ribs, decorations or raised letters) at the widest point. This measurement is made without any load placed upon the tire and after the tire has been properly mounted on its industry assigned measuring rim and has been inflated and reset to its test pressure after 24 hours.

http://www.tirerack.com/tires/tiretech/tirespecskey.jsp

AKA: Why I said it's a sidewall design, not actual width (IE: 225) because that stays constant.

[Rally]

All tire companies section widths vary even though the labeled sizes are the same.

True story. The autocross guys love finding tires that underestimate the labeled sizes so they can get as much section width as possible while still staying within the designated class rules. A 205 doesn't necessarily mean it's absolutely 205 wide...some are wider some are skinnier.

[simple g50]

nankang +1

+2. Nankang stretches nice and has a reinforced sidewall.

[Geoff.T]

215/40 is always going to be 215/40, not a 205/40. The reason why 512's LOOK smaller is the sidewall construction. Mathematically, they are the same.

Not true...

a Falken 512 in a 215/40 section width is 8.5in wide while the same size tire in a RT615 is 8.7in wide

Check for yourself under each tires specs and sizes.

http://www.falkentire.com/

All tire companies section widths vary even though the labeled sizes are the same.

[fatboy.yoshi]

Nitto NT555's are your answer.. they stretch great, good wear and are quality made... wet traction is the only issue i have heard, but that hasn't been the case with me.

word im rocking nt555's on my fronts and they stretch great...and i have not had any wet traction issues either...im running kumho spt's rears no probs either...and the stretch on both are great

[IIXtremeHansen]

damn thats horrible^^

[cheez80]

you are using falkens.
i use hte shit out of some nankang NS2s

nankang +1