Okay all you kids running 17's on your A-bodies, I need your input. I have a '72 Swinger, and I ordered a set of SBP 17x7 Coy's C-5 wheels back in May. They're having trouble getting grey 17x7's from their vendor, thus the delay. After talking to a guy from Coy's today, he suitably apologized and voiced his frustration. He DID mention, however, that he had a set of 17x8's there and ready for shipment, and offered to send them instead. Both the 7" and 8" widths have the same backspacing (4.5"). I realize tire choice would also be a factor, and I'm not looking for guarantees, but does anyone think they'd fit with a 225 or 235 tire? If the wheels had too much backspacing, like the Mustang Bullit rims, I know I could use billet spacers to position them properly, but with not enough BS, I'm worried they might rub on the front fenders. (I've got the front end a little lower than stock.) Anyone think it's worth the risk, or should I just wait for the 7's?

(DW, I'm especially interested in your opinion! )

Thanks!

VM

What aspect ratio will the tires be? 35? 40?





Never a problem on the 'net!

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

I guess I would be worried about 4.5" BS on an 8" rim. 5" is about right. If you went with 225/40s or 225/45s, it would probably be OK.

This is based on me running 225 width tires on a 15X7" rim with 4" backspace - worked on my 64 Dart.

Lou

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Home of Slant6-powered fun machines since 1988

I was hoping to run 50's if possible (trying to salvage some sidewall so the ride doesn't kill me), but only if I ran the 215's or 225's I was hoping for with the 7" width rims. If I go up to the 8" width, I guess I'd try 235/45's all around. My current 14's are 195/70's and are 24.7" in dia. I'm looking for a 25-26" diameter with the new tires. Doable on the front, y'think?

VM

I have 245/45-17s on 17x8s on the front of Project V. BS is 5.72" on the rims, but have the equivalent of about 0.75" spacer on there. Needed a little fender lip trimming.

Lou

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Home of Slant6-powered fun machines since 1988

So, 5.72" minus .75" is still around 5" backspace, as opposed to the 4.5" on the C-5's I'm getting. Even if I go with 225's or 235's, it doesn't look like an 8" rim will make it, huh? Heck, the 7's sound like they'll be tight...

I was hoping the fact that the Swinger's wheel openings sweep backwards might help with clearance. Guess it'll come down to careful measurements and a prayer...

VM

Lou, do you have the big-bolt brake upgrade? I know that adds some track up front. I have the KH disks, which, IIRC, I don't push the wheels out toward the fender lips. Am I grasping at straws here?

VM

Is this an overall question or a wheel/tire question? The 225 should be about 1/2" inch wider (per side) than the 8" rim. The edge of the 225 tread should only be about 1/2" farther out on the 8" rim than on the 7" rim, given the same backspace.

Given that wheel size it would seem like you might need to back off the diameter some.

Tire manufacturers will give a width measurement and state what size rim that measurement was made on:

For instance a 225/50 17 tire might say something like:

Diameter 25.9"
Width 9.2" on 7.0" rim *
rim width range 6.0" - 8.0"

* width changes 0.2" for each 0.5" of rim width.

So the above tire would have a width of 9.6" on a 8.0" rim...


Note: the 0.2" for 0.5" is actual, and is stated by different manufacturers.

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Thanks, emsvitil! Although I've seen wheel width specs, I'd never see what the effect is on tire width.

Ross, these particular wheels don't come in anything smaller than 17's, and several other Darts and Dusters are running the same wheels, presumably without interference. So the question I'm wrestling with is not diameter, but width of said wheels.

Guess I'll wait on the 7's, unless I can convince them to send me two of the 8's for the rear that I could test-fit on the front. From my understanding, 8" width on the back should be fine (again, depending on tire choice). Thanks for all the help, gang!

VM

The diameter comes into play when you turn the wheels, and over bumps, especially at the front corner of the front wheel opening.
Think in 3-D and check the extremes!

_________________
"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

Of course the part of the tire that might contact the fender lip - the tread - does not change in width, it is considerably narrower than the total tire width. and, at the same backspace, adding an inch in rim width will only shift the edge of it half an inch to the outside.