Slant Six Forum
https://slantsix.org/forum/

Big Wheel Question
https://slantsix.org/forum/viewtopic.php?t=18645		 Page 1 of 1
Author:  vynn3 [ Tue Jul 18, 2006 11:26 am ]
Post subject:  Big Wheel Question
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! :twisted: )

Thanks!

VM
Author:  slantvaliant [ Tue Jul 18, 2006 12:57 pm ]
Post subject: 
What aspect ratio will the tires be? 35? 40?



Quote:
... but with not enough BS ...


Never a problem on the 'net! :lol:
Author:  Dart270 [ Tue Jul 18, 2006 1:28 pm ]
Post subject: 
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
Author:  vynn3 [ Tue Jul 18, 2006 1:33 pm ]
Post subject: 
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
Author:  Dart270 [ Tue Jul 18, 2006 1:43 pm ]
Post subject: 
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
Author:  vynn3 [ Tue Jul 18, 2006 1:50 pm ]
Post subject: 
Quote:
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
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
Author:  vynn3 [ Tue Jul 18, 2006 4:34 pm ]
Post subject: 
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
Author:  RossKinder [ Tue Jul 18, 2006 5:52 pm ]
Post subject:  Re: Big Wheel Question
Quote:
does anyone think they'd fit with a 225 or 235 tire?

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.
Author:  emsvitil [ Tue Jul 18, 2006 9:53 pm ]
Post subject: 
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.
Author:  vynn3 [ Wed Jul 19, 2006 5:28 am ]
Post subject: 
Quote:
* width changes 0.2" for each 0.5" of rim width. Note: the 0.2" for 0.5" is actual, and is stated by different manufacturers.
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
Author:  slantvaliant [ Wed Jul 19, 2006 6:13 am ]
Post subject: 
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! :wink:
Author:  RossKinder [ Wed Jul 19, 2006 1:23 pm ]
Post subject: 
Quote:
So the above tire would have a width of 9.6" on a 8.0" rim...
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. :D
Page 1 of 1 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/