rim size

[vmrod]

One of these days, when the car is ready for the road, I'll finally be able to purchase some nice rims for my 1977. I wanted to know what is the widest rim I could put on the car, but still keep all 4 rims identical? (I am guessing that the front of the car will dictate the width of the rims.)

Also, what is the required backspacing? Is there anything else I would need to know when sizing rims? (I have stock trailing arms, and would consider changing to offset trailing arms, only if the front of the car could also 'wear' the same size rims as the rear.)

-Vic

 

[69MyWay]

Vic, I am virtually certain you can go 5" back spacing all the way around on a 9.5" rim, and or a 10" rim if you want it really tight. Remember, a 9/5" rim is really 10.5 inches wide lip to lip. Or another way of saying this is to realize that your stock vette rims are 8" wide, but really right at 9" wide from outer lip to lip.

So, it becomes rather easy now to determine just how much more rim you can squeeze in there by looking at the stock offset, then imaging the new rim to move in or out from the stock location. You can usually move the wheel out between .5 to 1" to the outside of the car, and move the rim in 1" to the inside of the car without a need for offset arms. Therefore obtaining a 10" rim with at least one more inch of backspacing.

BTW, it is not so much the trailing arm you have to be concerned about as it is the rear leaf spring shackle. If you run 15-17" rims and go more than 4.5" back spacing, you will run the tire into the rear leave spring outer mounts. If you step into a 18" rim, you can run the 5" back space and clear the spring with no worries. Vette Brakes and Products makes a shortened rear spring for the above noted situation. Personally, for a few extra hundred dollars, I would go for the more aggressive rim size.

 

[vmrod]

Thanks for the advice. Right now, I don't know if my rims are stock or not. I know that I do not have any backspacers on them right now either. (The rim comes within perhaps 1/8" or less from my caliper.) I think another area of concern would be the emerg-brake bracket. It is as close to the wheel as the spring shackle.

I just put a brand new composite spring on the rear, so I don't think I wanna get another one at the moment. I think I could live with some 9.5" or 10" rims though! That would be much better than what I have now. I am sure I could get some 60s (or 50s) on there then.

By the way, you 69 looks awesome. (Currently it's my desktop picture!) I love the wide tires, but I don't think I want to add wheel flares to my car. At least not right now.
-Vic

 

[inferno-vette]

[qoute]I think another area of concern would be the emerg-brake bracket.[/qoute]

This can be relocateed to the another part of the trailing arm, it's a pretty easy job.
Paul