Re: [Chevelle-list] Tires

[Clint Hooper]

Title: Message

Backspace and offset are two different animals,John. However,if you need air shocks to keep the rear tires from rubbing the outer fenders,it's a sure bet your wheels don't have enough backspacing. It's a critical measurement on all wheels,not just 15". The bigger the tire,the more important it becomes. Clint Hooper H&H Custom,owner 1969 El Camino ProTourer 2001 H-D FLHR custom bagger http://dalesplace.com/misc/friends/clint/clint_hooper.htm ----- Original Message ----- From: John Nasta It seems like it's only people with 15" wheels who talk about backspacing. I guess I will be dealing with this soon myself.   There is good info and a diagram here:   http://www.high-impact.net/wheels/howtomeasurebackspacing.htm   I'm still not clear on how maximum offset has anything to do with the height of the caliper from the center of the axle, while minimum offset has to do with the depth behind the rim. I also don’t know why If (I) x2 (times 2) is greater than 12.125" (G), obviously your maximum offset must be just under 4" or why G is measured on the outside of the wheel while the caliper is on the inside, but I have time to figure this out.   My '70 Malibu has 15s on the back now and when the air shocks are not pumped up they rub. Offhand I don’t know the tire size, which could be the cause of the problem. I suppose I'm going to have to see how she sits with new shocks and then decide what to do about tires and wheels.