The Hows and Whys Of Going Up To 33 Inch Tires
I bought my Trailblazer back in 2002 and did not have a clear plan for modifications at the get-go. Two reasons: I always lease my vehicles, and back then there WERE NO modifications for our rides. It took me about 5 minutes to forget about the lease thing as I knew right away that I was going to buy the Trailblazer out at the end of the lease. Then, in the summer of 02 some mods started to appear. Air filter kits, JET chips, etc.
The BIG problem was the wheel (and suspension set up). As most everyone knows by now, GM for some reason decided to put a front wheel drive type set up on our trucks. This means a VERY HIGH offset for our wheels. Even more strange, they decided to use a practically non-existant bolt pattern of 6x5 for the wheels. And to top it all off, the front suspension set up has a protruding "knuckle" which limits even upping the tire size on the stock wheels! Almost makes me believe they did all this on purpose to stop us from improving the somewhat lame stock tire set up.
My specs were 16x7 wheels with a +50 offset. Tires were 245/70R16 with an approximate diameter of 29.5 inches. Needless to say there was nothing out there in terms of aftemarket wheels. As a small batch of aluminum wheels started to appear in early 03, I started to think about how I was going to outfit the Trailblazer in my usual summer/winter fashion. Note: up here in Toronto, SALT is used heavily in the winter so keeping any kind of aluminum or chrome wheels on all winter is basically not a good idea.
So in 2003, I was looking for tires I wanted to use on my stock wheels for winter driving and larger size polished or chrome wheels and performance tires for summer driving. My summer set is listed in my profile for anybody that is interested. The winter tires posed a problem as I really wanted to go with a wider tire than stock but that suspension hardware puts a big restriction on that.
This is when I started to look into spacers and adapters. I read many articles and opinions, talked to local people, and ended up deciding that I was comfortable with PROPER adapters. Specifically, NOT the kind that use the stock lug bolts and only push the wheel out, but this
kind. They bolt up to the stock lug bolts on our axles and provide new and stronger bolts for the wheels to bolt up to. The reason I ordered from Sam's Offroad was that they were the only shop back then (that I could find) that would get adapters made in our bolt pattern and would ship to Canada. There is much more selection these days ...
My original spacers were 1.5 inches thick, had 6x5 bolt patterns, and a center bore of 3 inches. With that extra 1.5 inches, I could get the tires I wanted for winter: Dayton Timberline 265/75R16. These would fit onto the stock 16x7 wheels. They are listed as 32" in diameter so I was a bit worried at the time about clearance.
However, after three winters, I can say that I have had no significant clearance problems. No left/right wheel well contact, only some rubbing on the top of the wheel well on major compressions.
So when I started to get into modifications again this past summer, I started to look for a third set of wheels/tires that would be more suited to offroad adventures. This wheel and tire combination really cought my eye:
Of all the wheels I looked at, I liked the simulated bead lock on this one the best. Its an Eagle Alloy Series 1378, 16x8.0 with a +5 offset. I also like that its black painted with only polished accents. Problem was that it only came in a 6 x 5.5 bolt pattern. As for the tire, I wanted to go very aggressive and of course, there was no reason to stick to a size I already had so I set my sights on a 33" tire as I knew I was also going to get a 2" lift. Still, front clearance was definitely going to be a problem.