[Tarl]

Hi All,

I am running Ridler 695 18x9.5 with 5.49 BS with a 255/45/18 tire. I am rubbing on inside of the inner rear fender at full suspension throw.

Anyone else running a similar setup without any rubbing? Let me know please.

Thanks!

[JLMounce]

Seems like your biggest issue is the size of the wheel and tire you're trying to stuff back there. The early A-body cars pre 68 are notorious for having limited space in the rear. My understanding is that not only do they contour inward towards the top of the wheel house, but there are also a few lips and shelfs in the wheel house as well. The inner frame rail is the limiting factor without notching.

Here's a comparison on the factory mid-tier wheel/tire vs what you have now. The backspacing you chose is actually about where it should be assuming it's the factory rear-end and it's still got a drum brake on it.

https://www.wheel-size.com/calc/?whe...96875in&sr=0in

There's some options here if it's the frame side that you're having issues with. If you've got some room on the outboard (fender) side of the wheel well, you can try a small spacer to push the wheel away from the frame side of wheel house. Assuming you don't go too far, that may be all that's necessary.

If you're still running a drum brake, you can also consider a basic disc upgrade in the rear (assuming you've got a disc up front already). The mounting surface for the disc is about an 1/8th inch thicker than the drum mounting surface. That will get you a slight break upgrade while also marginally pushing the wheel outboard at the same time.

Without absolutely nailing the backspace by physically measuring each wheel house, the car probably wants more like a 245/45/18 on an 8" wheel.

[hgerhardt]

On my '66 GTO, I have 255/45-17 tires all around and have plenty of room in the rear. You probably just have a backspacing issue. I was actually considering 285 tires next time around with wider rims.

So from your rubbing description, it's unclear whether it's the outboard side of the tire rubbing on the inner fender or is it the inboard side of the tire rubbing?

Regardless, from whichever side it's rubbing, see how much space there is on the non-rubbing side and if there's opportunity to space the tire inward/outward to make it fit.

[Tarl]

Yes, I am hitting on the inner portion of outer fender (already rolled the inner lip).

hgerhardt, what size rims are you running in the back?

Thanks!

[hgerhardt]

Originally Posted by Tarl

Yes, I am hitting on the inner portion of outer fender (already rolled the inner lip).

hgerhardt, what size rims are you running in the back?

Thanks!

I've got 8.5" rims, so those would pull in the major bulge of the sidewalls by ~1/4" on each side relative to your 9.5" rims. Forgot what backspacing I have.

How much clearance do you have on the inboard side of the tires? If there's significant clearance on yours there, that would mean needing more backspacing.

[JLMounce]

Your overall tire height is also an inch less. That will also make a difference in a lot of cases.

Tarl, if as hgerhardt states above you have a good amount of space inboard of the tire to the wheel house or frame, you can use the link I posted above to mess around with backspacing. Transfer your current wheel/tire specs and then play around with backspacing to see how the wheel will move for you.

The unfortunate part here is that if you're rubbing the fender, that means you need more backspace. The only way you can do that is with a new wheel or by shortening the axle. Either method would work to accomplish that goal, but neither is particularly inexpensive.

[65madgoat]

Your offset will be the issue. Plenty of room for that rim/tire size.

[hgerhardt]

Originally Posted by JLMounce

.....The unfortunate part here is that if you're rubbing the fender, that means you need more backspace. The only way you can do that is with a new wheel or by shortening the axle. Either method would work to accomplish that goal, but neither is particularly inexpensive.

Most 66's have the wide rear axle. If he does, he could swap in a '64-'65 to get 1/2" more clearance on each side.

[ID67goat]

Originally Posted by 65madgoat

Your offset will be the issue. Plenty of room for that rim/tire size.

Agree on this. I have 275/40-18 on mine and fits fine.

[Tarl]

Hi All, thanks for everyone chiming in. I have plenty of space on the frame side of the tire. I have tried the hammer method on the inner fender for more clearance to no avail. My offset is listed as 6 on the Ridler site for these 18x9.5 with 5.5 backspace.

I chose the Ridler 695 because they fit over my C5 brakes up front. They do offer a 18x8 with 4.5 inch backspacing and zero offset, but if I run 245/45/18 I might be in the same boat as its 9.6 wide but I loose an inch of backspace which to my limited understanding puts the outside of the tire in a similar area.

Love the wheels, but might have to change them to dial in a better backspace, but it's tough getting information on C5 brake clearance.

ID67goat, what size rim are you running?

Thanks everyone!

[ID67goat]

Tarl,

My rear fender lip is unmodified and the 275 tire is all that can fit in there. The wheels are 18x9.5, but I don't recall the back spacing and would have to pull a wheel to measure it. My back spacing probably wouldn't help you anyway since I have a custom width 9" rear.

Just to clarify...you are rubbing on the fenderlip side or the frame side?

[Tarl]

ID67goat,

I am rubbing on the fender lip side. Not actually the lip, that is rolled, above that is a buldge in the inner fender and the tire hits on full suspension throw on a bump.

Maybe a custom axle is for me... I do need posi...and c-clip so I can run 98-02 f-body rear discs easier.