Stretch and sidewall height

[Mike S]

I ordered 4 tires (205/45/17) Falken 912's, which arrived this past week. I want the front and rear to have matching sidewall height. The rear wheels are 8" wide while the fronts are 7" wide. Since the fronts won't be stretched and the rears will have a slight stretch, should I go with a 40 sidewall in the front to keep the outer diameter the same?

My theory is, stretching the rear will make the sidewall decrease causing it to look smaller than the front.

What do you think? Any input would be great.

[Anonymoose]

Hey dude, look here it will show all

Tyrestretch.com

Damn I should get $$$$ for the amount of times I refer that site! Hope you get it sorted

[aar0n.]

Overall diameter doesn't change with stretch. There's no rubber being added or removed so it remains the same even as the sidewall shape changes

[Mike S]

Hey dude, look here it will show all

Tyrestretch.com

Damn I should get $$$$ for the amount of times I refer that site! Hope you get it sorted

Thanks, I've looked there quite a bit. The photo's helped a lot.

Overall diameter doesn't change with stretch. There's no rubber being added or removed so it remains the same even as the sidewall shape changes

Right, I understand that there's no difference in material, but since the inner diameter of the tire is staying 17", the sidewall stretches inward causing the outer diameter to decrease. Is that not how it works?

I drew this up as an example. It's exaggerated to show what I'm referring to.

[Tuck&Poke]

doesnt work like that. In order for what your saying to happen, the circumference of the tire would have to decrease, which is impossible.

plus, a 205 on an 8 is not stretched. 205mm is approximately 8 inches

[Mike S]

doesnt work like that. In order for what your saying to happen, the circumference of the tire would have to decrease, which is impossible.

plus, a 205 on an 8 is not stretched. 205mm is approximately 8 inches

Cool, that's the answer I wanted. And the stretch will be slight if there's any at all. This is fine right now. When these tires wear out, I'll likely buy new lips to get another inch in width.

[Anonymoose]

Your right though, it 'looks' as if it's decreased. But really it shifted

|""""""""""| to /""""""""\

Fucken 10 inch yo!

[CSBolger]

doesnt work like that. In order for what your saying to happen, the circumference of the tire would have to decrease, which is impossible.

plus, a 205 on an 8 is not stretched. 205mm is approximately 8 inches

True, but an 8" wheel is a bit wider in actuality. Stretching a 205 on an 8" wheel seems to be dependent on bead width, tire sidewall (flat or rounded), and tread pattern. Both myself and a friend are running 205/45s on 8s and there is definitely some visual stretch. Not much, but it's there.

[Mike S]

True, but an 8" wheel is a bit wider in actuality. Stretching a 205 on an 8" wheel seems to be dependent on bead width, tire sidewall (flat or rounded), and tread pattern. Both myself and a friend are running 205/45s on 8s and there is definitely some visual stretch. Not much, but it's there.

That's what I'm seeing with these tires. The contact patch of the tire is roughly 7.25". If you include the widest part of the sidewall, it's 7.75". Then if you measure the distance between the outer edges of the lip, it's nearly 9".

It sucks not having more tire options. I need more wide.

[Tuck&Poke]

that's because the measurement is taken from inside the edge of the lip to the other inside, and that edge of the lip is roughly .5in on each side. Remember that the sidewall mounts within those boundaries. You guys are talking about stretch in the fractions of an inch.... i know as this gets more mainstream its gonna get less hardcore, but your still within the approved rim width, which is where i draw the line for considering a tire stretched. Not knocking on you, just saying.

[Han]

http://www.stanceworks.com/forums/showthread.php?t=3216

Rolling diameter does not change when the tire is being stretched. No material is literally being "stretched," but just the point of where the beats seat and mount is being moved, in turn, tilting the sidewall to an angle to seat at said point.

[Mike S]

Yeah I was just saying that the lip will be wider than the tire so it won't look like my OEM wheels where the tire is wider than the wheel.

The only reason I wanted some stretch on these tires is because the offset of the new wheels should put them flush with the fender. Next time around, I'll go more aggressive. This is sort of an experiment for me as this is my daily driver. I'll still be smashing pot holes and speeding over train tracks just like before.

Can't wait to get them mounted up.

[Mike S]

http://www.stanceworks.com/forums/showthread.php?t=3216



Rolling diameter does not change when the tire is being stretched. No material is literally being "stretched," but just the point of where the beats seat and mount is being moved, in turn, tilting the sidewall to an angle to seat at said point.

Damn, sorry I missed that. Thanks for the link.

[Lux]

Wow, now I'm confused.

See, in a thread I started I was told that I would have a lower profile if I was to go from my current 235/35 to a 215/35 and noticeably less rubber.

Also, different tire manufacturer's also have different specs on max and min wheel width.

Federal for example does not recommend over 7.5 on a 225. You also have to think about the sidewall. They fluctuate the recommended widths with the side wall as well.

My 235/35 is square maybe a sliiiiiight visual stretch on a 8.5 which are Nexen N3000's.

[FreshLikeSushi]

doesnt work like that. In order for what your saying to happen, the circumference of the tire would have to decrease, which is impossible.

plus, a 205 on an 8 is not stretched. 205mm is approximately 8 inches

no dude
you are wrong

its MM difference, but you are wrong.
if you put a 205/40 on a 9 and a 10, the 10 will have a smaller outer diameter. i actually measured it a while back in an argument, and it was negligible, but there was a difference.