Got a problem...

chevy#8 · February 16, 2006

Hey guys, I went today to buy my lift, wheels and tires and then have it all installed sometime this week but when I told the people at the shop what wheels I wanted he told me that they wouldnt work because the wheels have a negative backspacing. I was going with a Fabtech 6" lift, 35X12.50 20 Nitto Mud Grapplers and 20X10 Helo Maxx 6 wheels. I was told that becuase of the negative offset of the wheels he would have to either have to do some cutting on my truck( which isint happening) or I would have to lift it higher. I dont mind lifting it higher but I dont wanna lift it so high that it looks funny, like the truck is sitting above the tires and I dont mind going with another wheel but I really do have my heart set on these. So my question is what are my options? and if someone could explain the whole offset thing to me that would be great too! lol Thanks in advance. Sorry this was so long Im just confused.

94redZ · February 16, 2006

My lift on my truck (a 94 Z71 ext cab RCD 6") told me that I shouldnt really use 35 inch tires with a 16x10 inch wheel, too wide. They suggested a 16x8 wheel, might want to see if they have a thinner wheel for you. If not ask the place where you bought the wheels if the manufacturer sells that wheel with a different backspacing, most good wheel companies do. Backspacing is ...how do i explain this...

Take your wheel, put it outside face down, and put a peice of flat wood across it. Then take a tape measure and measure from the inside flange on the wheel (where the lugnut sleeves are) to the bottom of the wood. This should give you the backspacing of your wheels.

Some manufacturers dont want you to use a large backspaced wheel because it will cause clearance issues with the aftermarket drop knuckles, but on the other hand, if you get a wheel with less backspacing, it will increase your track width, then you will need wheel flares or you will scratch up your truck from road debris. Id say talk to the wheel manufacturer before you ditch your current wheels.

20" wheels????? Hmmm they might be so big that you wont even have problems with knuckle clearance, but another option, though not the normal way, is to grind down the knuckle, but Id steer away from that if I were you.

Ps. I might have my expression of backspacing mixed up (in terms of large vs. small) I know what Im saying just get mixed up saying it. Someone back me up if you can, so this guy can get good info.

rob

chevy#8 · February 17, 2006

I called the guy today who sold me the wheels and he said that they only offer that particular wheel in a 5in backspacing and the lift im going with(Cognito) only allows for a 4.75 inch backspace maximum so I just said screw it and decided to go with the same wheel just in an 18X9 and I was told they should fit perfectly. I too was told that the 20" wheel being so tall that it should clear the knuckle so there shouldnt be a problem there but I wasnt about to take that chance so I just went smaller. I think it will look fine I mean 18 is still a big wheel. But thank you 94RedZ for explaining the whole backspace thing...sure did make it ALOT clearer on my end. So I guess you could say that the problem is resolved. Thanks alot for the info. Later.

03HD · February 17, 2006

I called the guy today who sold me the wheels and he said that they only offer that particular wheel in a 5in backspacing and the lift im going with(Cognito) only allows for a 4.75 inch backspace maximum so I just said screw it and decided to go with the same wheel just in an 18X9 and I was told they should fit perfectly. I too was told that the 20" wheel being so tall that it should clear the knuckle so there shouldnt be a problem there but I wasnt about to take that chance so I just went smaller. I think it will look fine I mean 18 is still a big wheel. But thank you 94RedZ for explaining the whole backspace thing...sure did make it ALOT clearer on my end. So I guess you could say that the problem is resolved. Thanks alot for the info. Later.

<{POST_SNAPBACK}>

If you insist on the fabtech lift then you will have to do what you say because it is a spindle lift. (Note, the fabtach lift also spaces out the front track about 3 inches so your front tires will stick out more than the back). If you go with a ProComp lift which is not a spindle lift, but relocates the upper control arm you can use the 5" backspaced wheel without any problem. This is what I did. I had to have the 17x10 Diamo 17 Karat wheels and they have a 5" backspacing, so I went with the procomp lift. It is a more difficult lift to install, but it is a great lift. Also the procomp lift does not increase front track width, but maintains the factory width in the front. Maybe this is too late, but maybe not. Let me know if I can explain anything more...