This is why tires need to have sidewall measurements.

"Coty" (coty)
08/09/2015 at 17:03 • Filed to: None

These didn’t. What. The. Fuck.

DISCUSSION (25)

ly2v8-Brian > Coty
08/09/2015 at 17:08

They do. Let's say P225/65R16 the number after the slash is the sidewall measurement.

lonestranger > Coty
08/09/2015 at 17:09

????

All tires have sizes on the sidewall.

Coty > lonestranger
08/09/2015 at 17:12

The size OF the sidewall.

Coty > ly2v8-Brian
08/09/2015 at 17:13

Okay, I understand that. These say 135 R15.

Goggles Pizzano > Coty
08/09/2015 at 17:20

Could be wrong, but it’s my understanding these tires have a sidewall height of 75% of the width. It’s the old standard.

Edit: Now see 505’s reply. It is 80.

Arch Duke Maxyenko, Shit Talk Extraordinaire > Coty
08/09/2015 at 17:20

Research isn’t that hard.

https://www.cokertire.com/135r15-firesto…

505 - morphine not found > Coty
08/09/2015 at 17:20

Which means they are 135 / 80 R15. If there is no number, it’s 80. Don’t know why, maybe because first radials all had this same sidewall index, and /xx only came to play when it differentiated.

Coty > 505 - morphine not found
08/09/2015 at 17:22

I was gonna say, who the fuck came up with that rule?

Coty > Arch Duke Maxyenko, Shit Talk Extraordinaire
08/09/2015 at 17:26

Yeah, not hard but that’s not useful in any way.

ly2v8-Brian > Coty
08/09/2015 at 17:30

Title made it sound like you didn't know. Sorry

Arch Duke Maxyenko, Shit Talk Extraordinaire > Coty
08/09/2015 at 17:32

Overall Diameter: 23.57

“not useful in any way”

That Bastard Kurtis - An Attempt to Standardize My Username Across Platforms > Coty
08/09/2015 at 17:34

Wouldn’t taking the overall diameter of the wheel and subtracting 15” for the wheel have yielded the sidewall height?

Coty > Arch Duke Maxyenko, Shit Talk Extraordinaire
08/09/2015 at 17:35

Thank you for telling me what I said because if you hadn’t of I might not have know that I had said it either while I was typing it or after.

Coty > That Bastard Kurtis - An Attempt to Standardize My Username Across Platforms
08/09/2015 at 17:38

It’s more the fact that I ordered the tires and they didn’t have an aspect ratio (the second part of the usual tire measurement nomenclature, 155/ 65 R15 for example).

Some people seem to think that having the overall diameter will do just fine, but when I’m away from the car and don’t have time to measure it just to appease Firestone/ Coker’s being too awesome to include a very basic measurement, it really doesn’t.

505 - morphine not found > Coty
08/09/2015 at 18:46

No idea, but I gone and checked what i told you and it was almost perfectly correct: it’s 82%, not 80%, but i guess they would never write /82 on it anyway. See wiki: https://en.wikipedia.org/wiki/Tire_code

Anima > Coty
08/09/2015 at 19:12

Well. the logical solution is to baja the heck out of it. Then it will fit.

Dusty Ventures > ly2v8-Brian
08/09/2015 at 20:36

No, it's not. It's the ratio of the sidewall to the tread width. So a /65 is 65% the size of the tread. In other words a 185/65 has a different size sidewall from a 225/65, even though the number after the slash is the same.

That Bastard Kurtis - An Attempt to Standardize My Username Across Platforms > Coty
08/09/2015 at 21:16

I gotcha. I mean I understand why they did it, making a period correct tire. But yeah, maybe they could give you a “this tire is a size 185/15, which is a 185/80/15 in modern sizing” or something.

ly2v8-Brian > Dusty Ventures
08/09/2015 at 21:23

Yeah. That's how it's measured.

Dusty Ventures > ly2v8-Brian
08/09/2015 at 21:40

Sorry, I was on mobile and misread the whole thread. I thought the issue was that tires don’t provide a straightforward sidewall size (as in one where you can look at the number and immediately know the size without having to do math).

ly2v8-Brian > Dusty Ventures
08/09/2015 at 21:52

It's all good. I sort of did the same to coty.

gmporschenut also a fan of hondas > 505 - morphine not found
08/09/2015 at 22:43

Very close. depends on year

“

!!! UNKNOWN CONTENT TYPE !!!

Prior to 1964, tires were all made to a 90% aspect ratio. Tire size was specified by the tire width in inches and the diameter in inches - for example 6.50-15 . [22]

From 1965 to the early 70’s, tires were made to an 80% aspect ratio. Tire size was again specified by width in inches and diameter in inches. To differentiate from the earlier 90-ratio tires, the decimal point is usually omitted from the width - for example 685-15 for a tire 6.85 inches wide.

Starting in 1972 tires were specified by load rating, using a letter code. In practice a higher load rating tire was also a wider tire. In this system a tire had a letter, optionally followed by “R” for radial tires, followed by the aspect ratio, a dash and the diameter - C78-15 or CR78-15 for bias and radial respectively. Each diameter of wheel had a separate sequence of load ratings, thus a C78-14 and a C78-15 are not the same width. 78% aspect ratio was typical for letter sized tires, although 70% was also common and lower profiles down to 50% were occasionally seen. [23] ”

gmporschenut also a fan of hondas > Coty
08/09/2015 at 23:01

http://www.vintagecarconnection.com/vintage_tire_s…

On older cars it becomes a pain in the ass as people would often mix/match tire sizes for better fuel efficiency or acceleration, an many will argue about safe levels of width. “oh yeah they fit you just have to be careful and no lock to lock turns”

Your boy, BJR > Coty
08/10/2015 at 03:04

HAHAHAHAHA

Coty > Your boy, BJR
08/10/2015 at 08:25

Do you plan on laughing more or less when they still fit?