Fox T-Bird/Cougar Forums

Technical => Misc Tech => Topic started by: fordman3 on July 31, 2005, 10:30:28 PM

Title: Widest allowable tire and/or shims/spacers?
Post by: fordman3 on July 31, 2005, 10:30:28 PM
Hey all,
I've got a couple questions regarding my 16" snowflakes on my '83 LS.  The tires I've got mounted (the ones that came with the wheels) are 225/55R16's, which look great under the fenders.  I like for the fenderwells to look filled out.  I've never actually put any miles on these wheels/tires since I bought them.  They've just sat in the driveway under whatever project car I had at the time and never actually went anywhere.  Anyway, I noticed today when I mounted the fronts on my '83 and had one fender removed, that the inner sidewall sure appears to be in contact with the strut.  If it's not, then there isn't but a couple thousandths clearance.  What are my options, because I really like these tires.  Are there shims or spacers I could put behind the wheels to get the tires safely off of the struts?  These wheels have a really deep offset, and these tires on another rim probably would have no trouble.  Or, do I just need to go to a narrower width tire, like a 225/60R16, which doesn't look quite as aggressive but is a lot more common?  Anybody else had these issues?  Thanks for the input.

Fordman3 

P.S. I know, I know, I really have no need for 55's behind a carb'ed V6, I just like the look.
Title: Re: Widest allowable tire and/or shims/spacers?
Post by: SLEEPER T-BIRD 87 on July 31, 2005, 11:38:09 PM
you can get some 1/4 inch wheel spacers just make shure to check the wheel torque every so often
Title: Re: Widest allowable tire and/or shims/spacers?
Post by: slamedcat on August 01, 2005, 12:12:34 AM
Quote from: fordman3
P.S. I know, I know, I really have no need for 55's behind a carb'ed V6, I just like the look.



I ran the same size on my v6 bird. They were cheap fit well in the openings especialy after dropping the car 1in.

I ran 1/4 in. spacers on the front of the bird to keep the rubbing down when turning.
Title: Re: Widest allowable tire and/or shims/spacers?
Post by: fordman3 on August 01, 2005, 01:20:53 AM
Hey guys,
Thanks for the ideas.  I haven't even checked to see if anything rubs when turning.  It looks like I'll be rubbing even in a straight line.  Quarter-inch sounds about right.  Where do I find 'em?  I'm assuming that leaves plenty of threads on the lugs, right?  Is there any need to use spacers on the back?  I doubt it, but you never know. 

Thanks again. 

Fordman3
Title: Re: Widest allowable tire and/or shims/spacers?
Post by: slamedcat on August 01, 2005, 06:45:55 AM
No there is no need for spacers on the back. Yes there is usualy plenty of thread left to bolt to. You can pick them up at your local parts store or speed shop.
Title: Re: Widest allowable tire and/or shims/spacers?
Post by: MasterBlaster on August 01, 2005, 08:13:09 AM
Just for the record, a 225/60 is not narrower than a 225/55.
225 is the "section width".
/60 /55 is the ratio of width to height.
The /60 is about an inch taller, so it just *looks* narrower.
Title: Re: Widest allowable tire and/or shims/spacers?
Post by: fordman3 on August 01, 2005, 10:41:27 PM
MasterBlaster,
We might be saying the same thing two different ways, or vice versa.  Yes, a 225/60 and a 225/55 have the same section width, 225 mm, which is the measure from the center of the tread to the inside lip of the sidewall.  But the aspect ratio describes what percent of that section width is sidewall and what percent is tread width.  So a 225/55 has 55% of its section width in the sidewall, and 45% of the section width in "half" the tread (to the center line).  A 225/60 has 60% of its section width in the sidewall and 40% of its section width to the center of the tread.  That is what I mean by a wider tire.  A 55 series is always wider than a 60 series if the other measures are the same.  That's why there are different series, so people can pick and choose the height and tread width that best suits them.  Vettes, Vipers, and other high end sports cars have 30 and 35 series rubber on them, and they are nothing but "fat".

Before I sold my '69 Mach 1 Mustang a couple years ago, I decided I would put the same size rubber on the front as I had on the back.  The rears were 245/60R14's, and the fronts were 215/70R14's.  The fronts were a little taller, but not much.  Well, I wanted 60's on the front to match the rear, plus I would be able to rotate them.  I had the 245/60's mounted on the fronts, took them home and proceeded to mount them, and whammo!  I slammed the tires hard into the front shocks.  The lug nuts wouldn't begin to tighten down.  I'd seen plenty of other '69 Mustangs with 60's on the front, but I guess my wheels were not the correct offset to allow anything but 70's.  Just an example. 

Hey, by the way, I know where a pair of take-off 245/50R16's are (pretty used, but probably still fine for a little while longer) that I may put on the rear of this same car.  The diameter works out to almost exactly the same as the 225/55, and man, would that look nasty.  What do ya think?

Fordman3