Lippy's ERA #797 build log

[ERA Chas]

The front tires are incorrect- they should be 60 series not 65. They are too tall.

[DanEC]

I missed the tire size in Lippy's thread. Yes, those are probably the same heigth tires as my 215/70-15 tires. Same interference.

[lippy]

Originally Posted by ERA Chas

The front tires are incorrect- they should be 60 series not 65. They are too tall.

Chas, you're right that the math says the OD of the 225/65 is larger than the OD of the 235/60. Avon doesn't make the 235/60, so ERA recommended I go with the 225/65 and mentioned there shouldn't be a problem.

[ERA Chas]

Originally Posted by lippy

Chas, you're right that the math says the OD of the 225/65 is larger than the OD of the 235/60. Avon doesn't make the 235/60, so ERA recommended I go with the 225/65 and mentioned there shouldn't be a problem.

Well now you know there is. All the tires sizes are different per manufacturer.
I had 4 sets of Hoosier TD's, size 245 / 60 on the fronts for 8 years. Like all ERA's with any tire, the driver front will rub on the inner fender panel (where the screen vent is) and the pass side will rub a little less.
That's only at full lock at parking speeds. You're never at full lock any other time, even in auto-x.
For the record, my front BB's with 26.5" diameter had a circumference average of 82.875 to 83.187 and rubbed no worse than the TD's.
It's always wise to check circumferences and adjust up to the highest (or have a bad set shaved). Radials are more closely sized but I'd check anyway.

[lippy]

Originally Posted by ERA Chas

That's only at full lock at parking speeds. You're never at full lock any other time, even in auto-x.

Problem is I have interference on the driver's side at full extension, but when the wheel is only turned say 1/4 of way in. Not at full lock.

[DanEC]

Originally Posted by lippy

Problem is I have interference on the driver's side at full extension, but when the wheel is only turned say 1/4 of way in. Not at full lock.

ERAChas - the difference is we are hitting the fiberglass lip on the newer bodies instead of rubbing the wheel well aluminum. My tires clear the aluminum fine.

[ERA Chas]

Originally Posted by DanEC

ERAChas - the difference is we are hitting the fiberglass lip on the newer bodies instead of rubbing the wheel well aluminum. My tires clear the aluminum fine.

OK I see. The answer is still a lower aspect ratio. I'd rather change tire profiles than remove fiberglass unless it's just a trace amount.

[ERA Chas]

Originally Posted by lippy

Problem is I have interference on the driver's side at full extension, but when the wheel is only turned say 1/4 of way in. Not at full lock.

Understand but if you're at full extension under-weigh, you're off-roading.
Not a normal condition for Cobra driving.