tire size!?!?!?!

Topic: tire size!?!?!?! (Read 4171 times) previous topic - next topic

tire size!?!?!?!

July 26, 2007, 05:47:31 PM

how big of tires can i fit on cobra R 17x9 rims? can i fit 10" in the back?

tire size!?!?!?!

Reply #1 – July 26, 2007, 06:50:43 PM

275/40/17 on a 9" wheel

and yes a 10" will fit with the right offset

tire size!?!?!?!

Reply #2 – July 27, 2007, 01:56:51 AM

what do you mean by offset?

tire size!?!?!?!

Reply #3 – July 27, 2007, 03:13:05 AM

The "ideal" section-width tire would be a 245 on a 9" wheel. When you go wider, the sidewall and bead area is pulled in to fit the wheel. You begin to lose the designed-in sidewall stiffness and cornering ability. It can also cause the tread to "crown" and wear in the center more at the required inflation pressure.

tire size!?!?!?!

Reply #4 – July 27, 2007, 03:19:45 AM

"Offset" is the difference from the center of the wheel to the mounting . It can be pos or neg.
Example:
A 10" wheel with 0 offset would have the exactly in the center, 5" from the back rim.
The same 10" wheel with 1" positive offset would have the mounting surface 4" from the back rim, with the wheel center shifter to the outside, making the -car's- "track" wider by 2", maybe requiring the fender lip to be rolled.
This same wheel would also be described as having 4" backspacing.

tire size!?!?!?!

Reply #5 – July 27, 2007, 06:37:22 AM

close.
offset is a calculation of the wheel centerline to the mounting pad, and is measured in millimeters.

backspace measures the inside wheel lip to the mounting pad and is measured in inches.

small difference in measuring systems that makes things kinda confusing when you try to go between systems. more info here.

tire size!?!?!?!

Reply #6 – July 27, 2007, 02:08:32 PM

Gumby is correct, except some companies DO list offset in inches(or used to).
That's what I get for posting in the middle of the night.....

tire size!?!?!?!

Reply #7 – July 27, 2007, 02:13:07 PM

if you're just wanting to fit the biggest possible... 315/35/17.

tire size!?!?!?!

Reply #8 – July 28, 2007, 01:02:17 AM

Quote from: Prototype Services;163720

The "ideal" section-width tire would be a 245 on a 9" wheel. When you go wider, the sidewall and bead area is pulled in to fit the wheel. You begin to lose the designed-in sidewall stiffness and cornering ability. It can also cause the tread to "crown" and wear in the center more at the required inflation pressure.

Would a 245 on a 9" wheel be ideal for traction on a drag radial in the 1/4 mile?
Tia
Mike

tire size!?!?!?!

Reply #9 – July 28, 2007, 02:05:16 AM

I worked for Goodyear in the mid '80s, before Zakspeed. Long ago.
I would check with a drag-tire expert to make sure. We worked the roadraces, but I asked about drag slicks just because I was curious. I think a drag tire will fit a slightly narrower wheel because of the taller, softer sidewall. Unless you are only interested in cosmetics, I would stick with their suggestions as to the ideal tire width. I had this proven to me once. I was given a pair of 255-50 roadrace tires for the rear when I had 8" wheels. The back end always wiggled and I was glad to be rid of them. I had to put a ton of air in them to keep from feeling like I was going to spin-out at everycorner, even on the street, and then wore them threadbare in the middle.

tire size!?!?!?!

Reply #10 – July 28, 2007, 09:31:24 AM

I have 255.40.17's in the back and 245.40.17's up front.You'll have to go 5 lug to use 10 inch Cobra R rims,as there aren't any 4 lug Cobras (believe me,I looked everyywhere).The 255's in the rear JUST clear my quad shocks.

tire size!?!?!?!

Reply #11 – July 28, 2007, 10:28:13 AM

I too think 315's will fit in the back. That is/was my plan.

tire size!?!?!?!

Reply #12 – August 03, 2007, 03:47:09 PM

because i still have the stock tbird rear end do you think i could fit 265's on the back?
im asking these questions now so i dont look stupid at a tire place..

tire size!?!?!?!

Reply #13 – August 03, 2007, 04:14:26 PM

Quote from: Prototype Services;164027

I too think 315's will fit in the back. That is/was my plan.

honestly, i don't think a 315 will fit under the ass of a tbird. i've got them on my ranger. i thought he was just asking what size tire could be fit on the rim.

tire size!?!?!?!

Reply #14 – August 03, 2007, 10:44:31 PM

but will 265's or 275's?