Correct tire size on a '72

[Gary42]

Greetings,

When I bought my 72 last year, I was advised by the dealer not to crank the wheels all the way to a steering wheel lock since the tires might rub on the body due to their size. He said this was because they were 70 series, not 60.

Checking the original owner's manual and a couple of tire web sites, I see that the car is supposed to take 215/70R15s. I currently have some very nice BF Goodrich Radial T/As (235/70R15). Here's my question:

I'm a little confused about this. At Vette meets, my tires certainly look larger than those of my C3 brothers (see attached picture). However, as far as tire height, I have the correct tires. I should have 70s, not 60s. What is everyone else running?

Another question: the owner's manual specifies width 215, not 230. Are my tires extra wide?

As always, comments appreciated.

 

[Stallion]

Richard Newton talks about a caliper clearance problem that C3 Vettes have if the wheels are too wide. What is the width of them? 8" maybe?

TR

 

[69autoXr]

While it may appear that you have the correct height tire, you must remember that the second number in the tire size, 70, defines the height of the tire as a percentage of the width (the first number in your case 235). Therefore, a 235-70 tire is taller than a 215-70, by more than an inch. I calculate a 235-70-15 to be about 27.95 inches tall, and a 215-70-15 about 26.85 inches. Of course, it depends on how wide your wheels are, but nevertheless, your tires are taller than a 215-70-15.

Chris

 

[Tom73]

The '72 came with F70X15 tires as standard equipment. These were not radials. The F70x15 would work out to be about the same as 215/70R15 or the 235/60R15.

I have 245/60R15 on my 73 and do not have any clearance problems.

tom...

 

[billybob]

I've posted this more then once but its a damn nice visual of tire size

http://www.miata.net/garage/tirecalc.html

I'm personally running a set of 255 60 15's all round with no clearence problems, heck the vette turns like a tank anyways

42.3 foot turn circle according to Popular Science but what do they know :L

Bill

 

[Stallion]

What exactly does "Radial" (R) mean when it comes to tires?

Thanks!
TR

 

[73383]

I have a question on this also. I have rebuilt my chassis, (frame off). However the emergency brake cable bracket clearance is to the wheel is less than 1/8 inch. The ear to the mickey mouse clip is even closer to the tire.

The car came with rallys and two different sizes of tires, 225/70R15 front, and 245/60R15 rear. I have tried both sizes on the rear. While the 225 give better clearance they are close enough to make me uncomfortable. Is this normal?

I would hate to mess up my powder coated trailing arms by moving and rewelding the bracket.

I built a 65 conv. in 1978 and do not remember this being a problem.

Dennis