Widest front tires

[Longgone]

There`s a ton of threads here that focus on the widest tire that will fit in the rear with stock wheelwells but hardly anything about the front. What is the widest tire you guys are running in the front? Rim size? Backspacing? I`m trying to emulate an F/60-15 on the front of my 68 Barracuda which seems to come out somewhere in the 235/60-15 range. Any input would be appreciated.

 

[clhyer]

Good topic, thanks for asking it.
C

 

[1968FormulaS340]

Well in my opinion it would be a 235-60-15 (maybe).

Some have tire to fender interference even with that size. A 2nd gen Barracuda really can't take much of a front tire without suspension mods or cutting the front of the wheel opening.

The problem is that if you get very wide or much over 26" tall the swing of the tire as you turn catches and folds the front of the fender. We have had many threads on this.

Several guys have caught a fender with 225-60-15s

 

[rob_robinson87]

Depends on several factors. To get a larger choice of wheel, many have converted over to the 73+ disc brakes. This pushes the wheel out from the original location about 1/2 inch per side. Because of this, the backspacing is critical for the correct fit.

I do know of people getting away with 245/45/17 up front with wheels with 5.5 inch backspacing. Of course this again is with the 73+ disc brakes. See michael mosely's experience with the set he was able to borrow.
http://home.roadrunner.com/~michael_mosley/tech/wheels.html

Here is another with 17" wheels and this time 235/45/17 wheels. http://www.mooresmopars.com/ModInterior.html

I have done the conversion and run standard size 15x7 Cragars with 225/60/15, but I had to do some trimming on the edge before I took it to paint so they would clear. I only took out a pie shape just enough for them to fit.

Hope this helps.

 

[autoxcuda]

There`s a ton of threads here that focus on the widest tire that will fit in the rear with stock wheelwells but hardly anything about the front. What is the widest tire you guys are running in the front? Rim size? Backspacing? I`m trying to emulate an F/60-15 on the front of my 68 Barracuda which seems to come out somewhere in the 235/60-15 range. Any input would be appreciated.

I have a bazillion different tires and rims on the front of my 68 Barracuda over the years. My car has the large bolt pattern 73-76 disc brake conversion.

Just remember alignment settings, past owners' collision damage, factory variation all play into the sceme of thing when you are pushing the limit of tire size. The first place where you need to look is the front lower fender lip edge.

225/60/15 with 15x7 4.25 backspace in the front is about the biggest. Must run absolutely no less than 4.25" backspace. 4.5 would be better and that is max with a 15" rim. There's a member here Mulinex (sp?) that ran that same setup and it rubbed backing out a driveway and bent a fender.

The alignment's caster setting factors into this too. The more postive caster you run, the front tire move backwards away from the front lower fender lip edge. I run Moog offset 7103 bushings with 4.5 degrees of postive caster. If you run adjustable front strut rod bushing and you shorten them to get your caster, you will move closer to the front lower fender lip edge.

So, my 4.5 degrees of postive caster is helping me with clearance. Also have have poly front strut rod bushings that compress less when backing out of a driveway. And I have 1" torsion bar that don't allow a ton of travel.

The good thing about the 225/60/15 tire size is they there is a ton of choices for tires. And best off, there are some good handling tires in there too. The 235/60/15 are pretty much muscle car type radial T/A's, Cooper, Eagle ST. You can buy a better 225/60/15 tire that will out grip a 235/60/15.

Other setups I've run in the front since 1993...

245/50/15 with 15x8 4.5 backspace very close

245/50/15 with 15x7 4.25 backspace close

225/50/15 with 15x7 4.25 backspace

225/50/15 with 15x7 3.75 backspace rubbed slightly

245/50/15 with 15x9 4.125 backspace HIT with unmodified front fenders. So I folded back the bottom front and rolled the upper lip.

Here's a picture of the car with 225/60/15 and 15x7 4.25 backspacing cop rims. 15x7 rallyes are identical dimensions. Sorry it's small.

 

[autoxcuda]

....

I have done the conversion and run standard size 15x7 Cragars with 235/60/15, but I had to do some trimming on the edge before I took it to paint so they would clear. I only took out a pie shape just enough for them to fit. .....

Rob what is the backspace of that 15x7 Crager? Usually they are 4.0 inches. That and the 235 wide tire will usually do you in with an un lipped fender.

 

[340Dust-her]

I have 225/60R15 up front with 15x7 and it looks plenty wide. 4" backspacing.

 

[rob_robinson87]

15x7 unilug with 4.125 backspacing. Which is the problem with the 225. But they clear now and fit pretty good. Also, if I decide to go 17", it may give me a little wiggle room to fit in the 245s... we will see. I'm happy with the 15s at the moment.

 

[340Dust-her]

The one on the left is a 225/60R15 sitting next to a 255/60R15

 

[69swinger340391]

I have 225/70/14's on the original 14x5.5 small bolt pattern steel wheels.

There are no interference issues, but it is very close to the lower portion of the front fender when turning the wheels.

 

[rob_robinson87]

I corrected my posts.... I was having a brainfa.. well, you know. I have 225 on the front and they still rubbed before trimming. Sorry for the confusion.

 

[autoxcuda]

I have 225/60R15 up front with 15x7 and it looks plenty wide. 4" backspacing.

Have you run them on the car yet??

The Duster fender are more slab sided at the bottom. The 67-69 Barracuda fender curl under and can catch the tire as it turn through it's radius.

The Duster fenders have a fender support brace at the bottom lip, correct? I know 67-69 Darts are that way. Most A-bodies without a lower front valence have a lower fender support brace.

With the lower fender support brace, you can adjust the fender outward to give you a little more room. Or you can even drill another hole forward of the factory hole and that will push out the fender even more. I did that with my 68 Dart and fit 245/60/15 with 15x6.5 rallye rims. I pushed the fender out a good 1" or so.

 

[340Dust-her]

I corrected my posts.... I was having a brainfa.. well, you know. I have 225 on the front and they still rubbed before trimming. Sorry for the confusion.

So I guess it's safe to say that 4" backspacing is the best bet.

 

[autoxcuda]

So I guess it's safe to say that 4" backspacing is the best bet.

Since you don't have a front valance keeping the bottom of the front fender rigid, I think you can adjust it to fit. The fender edge will probably need to come out an inch. At least a 1/2". So unbolt your support brace now, pull the edge out an inch or more and see if that works for you.

Here's what I did to my Dart.

The factory fender support hole is in the rear.

 

[autoxcuda]

This is a little off topic. But this is the process I used to lip and bend back my front lower fender lips on my Barracuda to fit those real wide 15x9 minilites with only 4 1/8" backspacing and 245/50/15 tires. Same idea just to a lesser extent can be used for other cars.
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I got a set of Minilite copy rims made by Optima at a swap meet a couple years ago for my 68 Barracuda. They are 15x9 with 4 1/8” backspace, -0.9” offset. I wanted to run them with my 245/50/15 tires that were previously on my 15x8 rallyes with 4.5 backspacing, and 0.0” offset. Obviously this was going to put the tire out closer to the fenders and I was close right now.

So I lipped the front fenders. I did this because in the future I will be running 275/40/17 on 17x9 rims as funds allow. I knew from others experience I had to move the front lower edge of the fender back. I installed a spare 245/50/15 on the new rims to mock them up.

The idea is to have the rod supporting the inside to fold against and get a contour. I had hand dolly also supporting the rod. And the key was small hammer blows and having patience. It ended up being pretty much a straight line because I didn’t put a couple relief cuts in it. Oh well, I feel I could reverse this if I had to.

I think I could have got away with about ¾” less this much cut back.