Had hoped my first post would be an introduction and photo of my new Sierra 2500HD with the new shoes, but instead I come asking for advice:

Big O Tires here got me a good deal on a set of 17x8 Moto Metal wheels and BFG ATKOs 285/70R17s. I went in today to get them mounted and they had the wrong wheel. The wheel they had was a 17x9, so I told 'em to give it a shot. They looked GREAT but when the tech turned the wheel while backing the truck out, the tire damn near ripped the lower bumper cover off before he straightened it back up. They turned up the torsion bars until the truck looks level (the front is actually 1.25 inches lower as measured at the top of the wheel wells) and aligned it, but the clearance is not even really close.

We took the wheels off and put the stock baby buggy wheels back on. They will have the correct wheels tomorrow, and my tech said the narrower wheel would help - my question is this: how much of the lower bumper cover can I expect to lose in order to make these things fit? Is there any downside to hacking off a couple of inches from the cover?

I chose this wheel/tire combo because the local dealership has several new trucks sitting on the lot with these same sizes mounted (they look sweeeet but the dealership wants $3900 for the wheels/tires/nerf bars/spray bedliner package). When I looked through their inventory I didn't notice if they had trimmed the bumper covers, but I know the trucks were not lifted (I didn't buy from this particular dealer for various reasons, but we didn't part on friendly terms).

I have been reading this site nonstop for three days - what a great place!

Any advice is greatly appreciated!

Whats the offset on the new rims? With trimming the front spoiler, take as much off as you need, start small & keep trimming until it doesn't rub.

Also watch the inside fender by the door. If the suspension is compressed it may rub. The off set of the wheel should help. Also you may want to go with a 8" wheel.

With any lift you will need to trim the front fender, I know you don't have one but just letting you know that everyone is having to do it if they put on larger tires.

This is why a lot of us run the H2 wheels, the have a lot of offset so the tire sets in.

The wider the wheel and the wrong offset will cause more problems.

Thanx for the advice guys. Now I feel stupid because I don't know what offset the new wheels have. I was really just trusting the tire place to order the right thing for my truck - I see now that I should have taken a more active role in selecting the proper running gear. What offset is proper for this combo?

I snuck down to the dealer after closing last night and inspected the air dams on their trucks with similar wheel/tire sizes. They look to have trimmed off a couple of inches with a smooth radius cut. If I didn't know better, I would almost say the trucks had been shipped that way - the cuts were very clean (though the raw urethane was visible where the cut was made - I may paint mine). I have never cut a plastic bumper like this - what procedure should I use to get such a clean, smooth finish? A Dremel?

Again, thanks for your thoughts!

I just got some Nitto 305/55R20s and KMC Rockstar 20x9s. Couldn't find tha off-set but I know its wide. They rubbed BAD. I ended up having to put on some green keys, do some trimming on the inside and out side wheelwell as well as the bumper.I just used a air cut-off wheel and it looked good. Ill try to get pics this afternoon so you can see. Hope it all works out,
-Brennan

To cut back my airdam about an inch i used a steak knife, it worked great, also try zip tying the fender linder back in the back of it that is the other place that the tires rub. If your still having problems look into CognitoMotorsports.com they have a leveling system that brings up the front end and gives the smooth stock ride.

I have 285s on 18 inch wheels but approx. 1 1/2 smaller in diameter. These are mounted on 9 inch wide wheels in the front (5.75 bs) and 10 inches wide in the rear (6.0 bs). I removed the Bumper and cut a piece diagonal inwards with a jigsaw, any saw would work. I also cut the inner fender plastic cover the same way. With a higher wheel the bars have to be cranked probably up to 2 inches. I assume with a smaller bs in the front it will be more difficult to fit those wide wheel / tire combo...just my 2C

Much thanx to you all for your advice and assistance. The tire shop made a beautiful cut with an air cut-off wheel and clearanced the lower bumper cover so the tires wouldn't rub. It looks good - you wouldn't notice the cut had been made if you weren't looking for it.

Thanx again to everyone!

mountainstoner,
what shop did you go to? I just moved to slc but I am working at hill AF base. I have a set up in mind -- I want which is 18"x9" pro comps 1069 with the BFG A/T 285/65/18. I have been gun shy thinking that the set up would rub a bit. Anyhow just wondering if the tire shop took good care of you and if you would recommend working with them?
thanks

Phatty-

I went to Big O Tires on Antelope drive. They took good care of me, and I would recommend them. Ask for Ben or Travis. My truck is parked in front of bldg 385 most days if you want to see my set-up.

mntnstoner
I will have to drive by and look at your rig. Thanks for the info I will see what Big O can do...