Hello,

i just bought a set of Cragar S/S wheels for my ‘66 F85 Deluxe sedan. The size rims are 15x7 front and 15x8 rear. I have a doubt with de size tires. I’m thinking to put 225/70 r15 front and 235/70 r15 rear, anyone has this combo on his car?
Other size tires Fit well?
thanks !!

 

The rear is no problem as there is plenty of space, the front with 225-70's may rub on the rear of the wheel wells when you go through a good dip if the car sits low. I have 215-70's in front and 275-60's in the rear.

 

I have the 225/70-15 on the front of both my 66 cars. No clearance issues at all on either one

 

Whether or not your tires will rub depends on the offset of the rims in addition to the size of the tires. Someone else's experience with the same size tire and the same car is irrelevant if the wheels don't have the same offset.

 

the exacte size of my new wheels are:

The front 15x7” wheels: Cragar Super Sport, Steel, Chrome, 15 in. x 7 in., 5 x 4.5/4.75/5 in. Bolt Circle, 4.125 in. Backspace.

The Rear 15x8” wheels: Cragar Super Sport, Steel, Chrome, 15 in x 8 in., 5 x 4.5/4.75/5 in. Bolt Circle, 4.25 in. Backspace

 

Just to be clear, backspace isn't offset. Backspace is just the dimension from the rear edge of the rim to the wheel mounting surface, and can vary depending on the thickness of the lip outside the bead seating surface. The offset is the absolute dimension of the wheel mounting surface relative to the centerline of the tire (technically, to the centerline of the two wheel mounting surfaces) and is independent of wheel width or lip thickness. This is what matters for tire clearance. Depending on the thickness of the lip, your 7" wheel has somewhere between 1/8" and 3/8" of positive offset (the tire is pushed inboard relative to the wheel mounting surface). The 8" wheels have between 0" and 1/4" of positive offset.

 

[QUOTE=joe_padavano;1471582]Just to be clear, backspace isn't offset. Backspace is just the dimension from the rear edge of the rim to the wheel mounting surface, and can vary depending on the thickness of the lip outside the bead seating surface. The offset is the absolute dimension of the wheel mounting surface relative to the centerline of the tire (technically, to the centerline of the two wheel mounting surfaces) and is independent of wheel width or lip thickness. This is what matters for tire clearance. Depending on the thickness of the lip, your 7" wheel has somewhere between 1/8" and 3/8" of positive offset (the tire is pushed inboard relative to the wheel mounting surface). The 8" wheels have between 0" and 1/4" of positive offset.



thanks for your explain.

the 15x8 have Offset: -6.00mm
the 15x7 have Offset: +3.00mm

 

I agree with Joe P that offset will cause the tire to rub on the inner frame or the fender lip. Where the tires were hitting the wheel well had nothing to do with my wheel offset and everything to do with the height of the car and the condition of the springs when hitting dips in the road.