Wheel Expertise Needed with Adapters

[Mikey J 23]

I am working to decide on my 3rd set of wheels since I got my TB a few years ago. I am comfortable enough that I want to use some of the 1.5" wheel adapters this time as there seems to be less and less available to fit our bolt pattern. That said, I need some help from those smarter than myself on here.

I am looking at the 20" Helo HE835 with specs below:

Rim Diameter 20 inches
Rim Width 9 inches
Bolt Pattern (Number of Holes) 6
Bolt Pattern (Pitch Circle Diameter) 139.7 millimeters
Offset +18 millimeters
Backspace 5.71 inches
Bore Diameter 106.25 millimeters

My question is with the 1.5" adapters and these specs will I have any rubbing/other concerns with stock TB setup.
Also what would be the tire size I could run on these, again without rubbing or other issues. Any help is truly appreciated!

 

[HARDTRAILZ]

The tire size is the key, but that wide of wheel does make it more of a concern for rubbing. The backspacing is better than most I run so they wont be out as far.

Are you wanting larger tires or smaller or stock size?

 

[Mikey J 23]

Thanks for the quick response Hardtrailz, just the kind of expertise I was hoping for especially since your input on the adapters in some of the other threads really sold me that was the way to go this time.
For now I was hoping to just run stock size tires as my truck is a pavement pounder, daily driver. My last two sets have been 22x9 running 265/40R22, but this time around I am going for nice look, but little better ride. I definitely like the wheels being pushed out a bit and the width as I think it makes our TBs look a little more stout (yours looks like a beast).
The 1.5" vs. backspacing vs. offset is throwing me off quite a bit with these.
What do you think for tire size that would be closest to stock, but hopefully avoid rubbing.

 

[Sparky]

1.5" spacers effectively create -38mm offset. So if you got wheels that have a +12mm offset, combine that with -38mm and you'll end up with -26mm offset total.

Spacers increase backspacing by the thickness of the spacer since it pushes the wheel outward.

Offset is how far from the wheel centerline the mounting surface is (negative pushes the wheel outward, positive sucks it inward). Backspacing is the distance from the back of the wheel lip to the backside mounting surface.

Remember, wheel width is bead seat to bead seat, not outside edge to outside edge. A wheel measured from edge to edge is approximately 1" wider than the wheel width. I did not realize that until I was trying to figure out why my math wasn't working out and I did some quick research!

 

[Mikey J 23]

1.5" spacers effectively create -38mm offset. So if you got wheels that have a +12mm offset, combine that with -38mm and you'll end up with -26mm offset total.

Spacers increase backspacing by the thickness of the spacer since it pushes the wheel outward.

Offset is how far from the wheel centerline the mounting surface is (negative pushes the wheel outward, positive sucks it inward). Backspacing is the distance from the back of the wheel lip to the backside mounting surface.

Remember, wheel width is bead seat to bead seat, not outside edge to outside edge. A wheel measured from edge to edge is approximately 1" wider than the wheel width. I did not realize that until I was trying to figure out why my math wasn't working out and I did some quick research!

So the adapters would create the -38mm offset vs. the +18mm offset from the wheels = a -20mm offset total?

If I am reading correctly then the +18mm accounts for and is just another way of saying the 5.71in back spacing is off-center slightly pushing the wheel back?

That would lead to my next question then... -20mm offset with the adapters seems like enough to avoid rubbing, but what size tire?

 

[Sparky]

Basically. Offset is relative to the centerline of the wheel, backspace is relative to the back edge of the wheel. Same reference point (mounting surface), just measured from a different point to get different information.

It took me a long time to wrap my head around this, and I think the way that wheels/tires tend to mix units so that just adds to the confusion IMO.

Not sure what size tire you can use without rubbing on a stock height vehicle. And be aware the further out the tire wheel sticks, the wider the arc the wheel makes when turning so the greater the chance it'll rub front or rear of the wheel well when turning. I barely rubbed with a 31.6" tire and I run a lift to fit it vertically, so at stock height you probably don't risk much rubbing unless you have a heavier negative offset.

 

[Mikey J 23]

So to sum up - at stock height using the 1.5in adapters would equal -20mm offset total with 5.71in backspacing, does anyone see any potential for rubbing with these running a 275/45R20 tire size?

 

[Sparky]

No the backspacing is effectively decreased from 5.71 inches to 4.21 inches because of the adapter.

You won't hit any suspension, and height is fine. The tire might rub a bit on the liners at full lock due to the tire width but I'm not sure on that.

 

[Mikey J 23]

No the backspacing is effectively decreased from 5.71 inches to 4.21 inches because of the adapter.

You won't hit any suspension, and height is fine. The tire might rub a bit on the liners at full lock due to the tire width but I'm not sure on that.

I get what your saying... accounted for the offset change, but not for adjustment to the backspacing. So now would just be getting some first hand feedback from someone "cough-cough-Hardtrailz" (subtle hint...) as to whether he thinks it would clear turning or not, but even in worst case it would be on the max turn rubbing the liners (which could be modified easy enough)
Truly appreciate the time and input on this one guys! Especially for the help with the calculations Sparky

 

[smt 59]

Good day,
I am looking for a supplier for wheel spacers for my Envoy, I have read all the info and know the pro's etc. but I now require a supplier and which is the best product, I have learned that cheaper means cast aluminimum which is lower quality so I 'v been told. Has anyone dealt with Wheel-adaptor.com or wheeladaptor.com 2 different sites with different pricing and quality. Please advise if you know anything about these companies or let me know of one that we would all deal with here. Any info is appreciated.