Reconfirming wheel specs for 15x7 Options

[grantsfo]

I'm about to pull the trigger on a set of custom wheels and want to confirm backspacing and center bore for hub centric ring on a 1974 car. I will be running fat 205/50/15 Hoosiers on the wheels.

I will be having 15x7" wheels made with 4 lug 4x130mm bolt pattern.

Back spacing specs: I have heard everything from 4.25" to 5" for backspacing for 15x7 wheels. I'm not afraid of bending my fenders a bit to make things fit and I like the idea of a little wider track. Would 4 1/2" back spacing be enough for somone who has rolled fenders? I have lots of room now with rolled fenders and my 205/50/15 tires on 5.5" Fuchs - easily 2 to 3 inches

I do have centering ring on my front hub. Mueller provided dimensions of 78.60 mm x 15 mm which looks about right using my tape measurer. If I make an error I want to make sure its making this bore too big.

I appreciate everyones feedback.

[Demick]

All cars are a little different, so there isn't a single right answer. But the general rule of thumb on 7" wide wheels, is that a 5.00" backspace will very closely center the wheel between the inner wheel well and fenders which have been rolled and/or tugged out a bit.

The right thing to do is to take measurements on your current wheel/tire combo. measure the clearance between the tire and inner wheel well (hard to do), and the clearance between the tire and fender. Do this on both sides of the car as they will be different. From there, some simple math will tell you the proper backspace or offset you will require to center the wheel between the inner and outer fenders (if you have 4 bolt Fuchs, your current backspace is about 4.7" - you will need this info in your calculation). There won't be much room for error, but you will want to err on the side of having the wheels closer to the outer fenders than the inner fenders (a little less backspace) because it is much easier to massage the outer fenders to get the wheel/tire combo to fit. The inner fenders or wheelwells will be much more difficult.

Demick