Wheel back spacing

[Darrell C]

I'd apprecaite some input/thoughts on this subject. Sorry, it's kind of lengthy.

I've got an '03 TJ (yes, it's the Rubicon, but don't hold that against me Robert, I'm not sniveling ) It presently has a 1.25 BL and 1" MML. I'm planning a 4.5" suspension (RE) and 35's. My dilema is wheel backspacing.

The stock wheels are 16x8 with 5" BS, and research tells me 35's (315/75R16) will rub. Additionally, due to strength concerns (among the other benefits), I'm also planning a Warn hub conversion with alloy shafts in the near future (staying with 5 on 4.5) and the stock wheels will not accomodate that change. So, it sounds like new wheels are in order. Plus, I'd like to widen the stance slightly since I'm going up at least 4" (I hear RE's 4.5 nets closer to 5").

The wheels we like (wife and I) are Eagle 58's...looking at the 15" since they don't make the 5 on 4.5 pattern in 16". I'd like to stick with 8" wide to assist with bead holding when aired down. However, the Eagle 15x8 have 3.25 BS. Plus, with the 3/4" gained by the hub conversion, that's sticking out pretty far I think? The 15x10 are 3 5/8" BS. Somewhat better, but may not hold a bead as well (rumor says...no personal experience with 10" wheels).

Is the 3.25 BS coupled with hub conversion going to present any problems?

Should I try to choose another wheel? I have the SAF to contend with (Spousal Approval Factor which can be a complex mathematical calculation to say the least )

I don't mind staying with 16" wheels, but there aren't many 16" wheels out there with the TJ bolt pattern (unless I've missed them). 15" wheels are much more common.

Any other thoughts??

Darrell

[Deaver]

Darrell

I have 315-75R-16 MT/R?s mounted on Mickey Thompson Classic II?s (P/N 368421). This wheel has a backspacing measurement of 4-7/16? with a 5 on 4.5 lug pattern (wheels cost $112 ea )

I chose this config based on Backspacing and trying to keep the wheel/tire under the Flare as much as possible. PA Police and inspection can be picky buggers. The other consideration I made was going to WJ calipers in the future. This combo has worked well for me.

Keep in mind, that adding the Warn Hub Conv, It will add approx ?? to each side to the track width. I don?t have the hub conv (yet). Others with it can verify.
The lower the number of Back spacing, the farther your wheel/tire will stick out away from the body (increase to trackwidth)

Waiting to go on the trail

[Paradiddle]

Darrell - the fact that you have SOF is highly exciting!!!

I know (because I asked this question a year ago when I built my XJ) that the several of us on here run 4 7/16" (typicall referred to as 4.5") of backspacing on their Mickey Thompson wheels as Deaver mentioned. This seems to be a good fit for 35" tires on both a TJ and XJ and keeps the tire inside the flare.

Sounds like your are going to have a really nice Rubicon when you are done!

Jeff

[Jerry Bransford]

Just realize that the Warn hub kit also increases the front width by around 3/4" on each side for a total track width increase of 1.5". So while a 4.5" backspacing dimension works well with 35x12.50" tires and stock hubs, that same dimension will cause them to stick out more after a Warn hub kit has been installed.

I'm about to have that problem since I'm finishing my Warn hub installation today and my wheels have 4.5" of BS. Sometime soon, I hope to get the wheels tucked back in with new wheels with more backspacing. For the rear, I'll insert a set of spacers to counteract the additional backspacing.

[Darrell C]

Deaver,

Thanks for pointing me to the Micky Thompson wheels. I had not seen those and they look like a viable option. You mentioned going to XJ calipers. Are 16" wheels needed to allowed adequate clearance inside the wheel for those?? I know to expect decreased braking performance with the 35s and wasn't sure what I could do about it. Probably enough material on that topic for another thread.


Jeff,

Yes, getting a positive number the SAF is like keeping your checkbook in the black...just makes you feel better I get to mod the Jeep, and she's getting new carpeting throughout the house (and she wants new livingroom furniture to boot). These mods are going to break me

I'm willing to switch flares to cover the tires, but I don't want to get rediculous with track width either. I've also read that excessive backspacing can wreak havoc with wheel bearings.

I look at my Rubi (only my second Jeep and third 4wd vehicle) as a nice starting platform. I hoping it'll only get better with my planned upgrades.


Jerry,

Not sure if you're running the MT wheels or not, but I'm curious if the Warn hub kit will fit through the center of the wheel. I'd like to plan my buildup smart and not have to change wheels too many times. Even though I haven't broken a D30 axle or parts (35s are the biggest tire I've ever run) I want to minimize the chance...plus others won't have to wait for me if I breakdown due to a poorly planned Jeep buildup.


Darrell

[Deaver]

Originally posted by Darrell C
Deaver,

You mentioned going to XJ calipers. Are 16" wheels needed to allowed adequate clearance inside the wheel for those??


Darrell

Not XJ but WJ, Grand Cherokee dual piston Calipers. Depending on your Jeep, you may need other "enhancements" I am not close to being an expert on this subject. Others here are better and wiser suited to the task.

You may not have near the "trouble" others have had as yours is already set-up for disc/disc

[Stu Olson]

I run 3.5" BS rims with the Warn hub conversion. I personally don't see a problem with the width, etc. However, I live in AZ and no one gets anal about tires sitcking out of the flares either. For that matter, a lot of my friends don't even have fenders! LOL

[Darrell C]

Whoops, my mistake, I should have typed WJ calipers. Do they adapt over pretty well and is the braking efficiency improved with the conversion?

Yes, my Jeep is already disc/disc so that might eliminate some of the problems with the proportioning valve...then again, it might not.

Not meaning to change thread topics mid-stream...

[Darrell C]

Originally posted by Stu Olson
I run 3.5" BS rims with the Warn hub conversion...

What's your track width, Stu?? 3.5 BS with an additional 3/4" from the hub conversion is equivalent to running stock hubs with 2.75" BS. I've seen pics of your rig and it doesn't look like the tires are sticking out that far.

Did you plan on that wide a track width ahead of time? Or did it just work out that way and you haven't seen the need to change?

Darrell

[Stu Olson]

Yes, you have the numbers correct.

I got a pretty good deal on the wheels several years ago and couldn't pick or choose the back spacing with that price, so that is how I ended up with them.

As for the Warn kit, I knew what the results would be and was not bothered by that.

One other thing....I have a Sahara and although I've not broken out the tape measure myself, folks claim the flares are about 1" wider than Sport/SE models.

[Paradiddle]

Originally posted by Darrell C
Whoops, my mistake, I should have typed WJ calipers. Do they adapt over pretty well and is the braking efficiency improved with the conversion?

Yes, my Jeep is already disc/disc so that might eliminate some of the problems with the proportioning valve...then again, it might not.

Not meaning to change thread topics mid-stream...

Darrell - you need to talk to mrblaine - he is the WJ brake expert.

For a simple answer - yes the braking is greatly improved over the stock TJ brakes. Yes they adapt over "pretty" well but there is still work to make them work. Mark Hinkley from ORGS Manufacturing makes some of the important parts in a short kit for this mod.

Jeff

[Darrell C]

Thanks Jeff - I've been reading thru the archives and found that Blaine is a "guru" for many different things. When it comes time to tackle the brake issue, I'll definitely post accordingly and request some input.

For now, it looks like the Mickey Thompson Classic II's in 16x8 flavor will fit the bill. I'm leaning toward staying with 16" since it seems to accomodate the brake upgrades easier than a 15" wheel should I decide to head down that road.

[MJR]

One of these days I would like to run across a set of Rubicon wheels for my XJ.

15" wheels can be made to fit over the WJ brakes depending on setup but 16" are better. Most of the 8" wide TJ wheels are 5.25" backspacing like the Canyons I currently have. If you like the wheels and don't mind spending the money for spacers that is a way to go also. I run 1.25" on mine for 4" of backspacing on my XJ.

[Paradiddle]

Originally posted by MJR
One of these days I would like to run across a set of Rubicon wheels for my XJ.

I know an auto shop that carries those tires - only open after midnight

What is the backspacing of the Rubi wheels?

[MJR]

Originally posted by Paradiddle
I know an auto shop that carries those tires - only open after midnight

What is the backspacing of the Rubi wheels?

I won't ask where they came from.

I think it's 5.25" like the Canyons but I should measure some at work.

[Darrell C]

Originally posted by MJR
One of these days I would like to run across a set of Rubicon wheels for my XJ.

15" wheels can be made to fit over the WJ brakes depending on setup but 16" are better. Most of the 8" wide TJ wheels are 5.25" backspacing like the Canyons I currently have. If you like the wheels and don't mind spending the money for spacers that is a way to go also. I run 1.25" on mine for 4" of backspacing on my XJ.

I've considered spacers and keeping the Rubi (Moab) wheels. However, plans are being developed (and monies budgeted) for a Warn front hub conversion and the center hole in the Rubi wheel is awfully small...don't think it will accommodate that mod. But, truth be told, I haven't actually measured the center hole, and I'm not sure how large it needs to be to accommodate the Warn small hub conversion.

Does anyone know the minimum wheel center hole size to fit the Warn 5 on 4.5 setup?? Guess I should find this out before I plunk down $$ on new wheels.

Not sure what the bolt pattern is on an XJ, but if the wheel swap occurs I won't have any more need for the Moab wheels.

Darrell

[Darrell C]

Originally posted by Paradiddle
I know an auto shop that carries those tires - only open after midnight

What is the backspacing of the Rubi wheels?

Jeff - I thought it was 5".

[MJR]

Blaine would be the best person to answer that but I am pretty sure the hole has to be like 3" or more. The bolt pattern is the same on the YJ/XJ/ZJ/TJ 5 on 4.5".