Tires for Cragar Starwires 15 x 7

[bepnewt]

I'm about to purchase my tires to put on the 15x7 Cragar Starwire I bought for my '64. As far as I know, the car isn't currently lowered, but I can't be sure of that. The pic at the bottom is what it currently looks like, sorry about the contrast issues. The current wheels are 15x??s and the tires are 225s.

As it stands, the fronts will rub on full lock, which I can live with and just avoid as best as I can.

I'm fairly confident the Star Wire wheels I have are 4" backspace. If I remember correctly from what I read, that's just a little more than what came stock on the car, like 1/4" or so.

The tires I am about to purchase are P225/60R15s or P225/70R15s. I believe either will be fine with some probable rubbing at full lock but I just want to make sure that I'm not overlooking anything before I blow the $$$ on the tires. Based on what I've read in these forms, I think I'm ok with these. Does anything jump out as a problem running these tires?

How much difference would going up to a 235 make? Can I run 225s on front and 235s on back on 7" wide wheels? I'm eventually going to 8" on back when I find another 8" Star Wire to go with the extra one I have.

Also, I was thinking about running 70s in back and 60s in front to lower the front just a little. Would that have any impact on driveablilty?

I eventually will lower the car, probably 2", but it will be at its current height for a while.

[mt65riv]

Brian,

Good questions. The rears should be fine. I have run 255's on stock wheels in the rear with no problem.

The thing to consider with 70's in the rear and 60's in the front: the rears would have to be about 2 sizes bigger than front to look right. Check with a tire calculator ( Tire size calculator ). The rears would look skinnier even though they have the same 225 width.

Usually I ran 60's in the rear and 70's in the front. Maye 235 or bigger 60's in the rear and 215 or 225 70's in the front Trying to keep the diameters equal front and rear (see calc).

The best thing to do would be to run the 225's and get 1" or 2" lowering springs if you want the nose down look. You don't sacrifice ride and you can still rotate the tires.

Wires on Rivis have always looked cool! If I could afford them, they would be on my car.

Your a lucky dude!

[bepnewt]

Thanks, Mike. I'll stick with 225/70s for now and revisit when I get the other 8" to swap into the back.

I appreciate the information.

-BEPNewt

[RivNut]

Brian,

Before you mount any tires on the wheels, mount a bare wheel on the front and rear. Depending on the size of the wheel center and the rim that's welded to it, and how your spokes are laced, you'll first want to make sure that the wheel mounts over the aluminum drums. Back spacing might not be as big a problem as interior spacing.

The offset of the center piece to the rim will have a bearing on the backspacing. If I were you, I'd get a couple of straight edges whose length is the same diameter as the wheel. Lay them across both the OE wheels you have and the Star Wires. Determine if the mounting surface is exactly in the middle of the rim (offset) If it is, the offset is 0 - zero. Because the Starwire is 7" and your OE rims could be either 5.5" or 6" rims, the back spacing will probably be greater on the Starwire. The tires you run, if you choose 225/70's will have the same cross section (225mm) no matter what size rim you put them on. On a 7" rim, the sidewalls will just be straighter than they would be on a 6" rim. The beads will be closer together, but the cross section will remain the same.

Find a tire store that will work with you and trial fit some different sized tires. If you're okay with the rub you get with the tires you now have, mount the same size tire on the Starwire before removing any of the tires from the OE rim. Lay the tires/wheels on their faces and lay a long straight edge across the sidewall of the tire. Measure the distance from the straight edge to the mounting surface of the wheels. Compare the two. Chances are they won't be that much difference. Remember, it's the tire that's rubbing not the wheel. If they're fairly close you should be okay. If not then figure out if a spacer will help. If you need to use spacers, remember your lug nuts do not have as many threads holding them on. You should consider pressing longer studs into your front hubs.

Chances are your back tires/wheels will clear with no problems, but just to be safe, mount a bare rim on the rear axle as well and go through the same process. Look around in the archives and find some related threads. Use this link to compare OE and the Starwires, enter all of the info and see what results you come up with.

http://www.rimsntires.com/specs.jsp

You'll need rim diameter, rim width (measured at the bead, not the outer edges, offset. It will calculate backspacing for you. Remember, back spacing has to do with 1) rim width, and 2) offset. Then you can play with tire sizes. There are two images side by side. Put your OE info on the left side and the "wanna be" tire and wheel combo on the other side. You'll see exactly how they compare. At the bottom of the screen, there will be an analysis you can read. It will tell you how much closer the "wanna be" tire will be toward the fender, how much closer it will be toward the chassis, and how the offsets compare. You can then see what spacers will do by playing with the offset.

Take your time, find a tire store willing to work with you, and don't buy the tires until you've done a bunch of trial and error fitting.

Ed

Edited April 22, 2011 by RivNut
Added link (see edit history)