Wheel Backspacing

SanceB20 · 03-04-2009, 07:34 PM

I have a 2004 Rubicon with a 2" Rubicon Express budget boost and a 2" body lift. Im running 305/70/16 Dunlop Mud Rovers with stock Moab rubicon wheels. I was looking for some Cragar Soft 8's or either the Pro Comp 97's. How much of a backspace do I need?

wes19d · 03-05-2009, 01:47 AM

Seeing as that tire is around 12 inches wide I would run 3.75 or 4 inch backspacing.

wes19d · 03-05-2009, 01:47 AM

Thats what I run on rockcrawler 152's

**Wheelin98TJ** · 03-05-2009, 10:14 AM

Welcome to the forum.

Here is some good info from the FAQ on what backspacing you need:

Width

The tire width you can use on your TJ is determined by the backspacing of the wheel. Stock TJ wheels have backspacing ranging from 5"-5.5". A list of stock TJ wheel specifications including backspacing can be found HERE

The chart below is intended to be used as a guide only. Different tire brands will vary in actual width. You may have slight rubbing when turning full lock if you are running the MAXIMUM suggestion below.

emev0l · 03-05-2009, 11:08 AM

15x8 4" backspace $40 each at summit

http://store.summitracing.com/partdetail.asp?autofilter=1&part=CRR-3975812&N=700+115&autoview=sku

2005X · 03-05-2009, 11:59 AM

"4BS on my cragers with a 12.5 wide tire

**TheBoogieman** · 03-05-2009, 12:07 PM

It depends also how far do you want them to stick out past your flares.Some states actually have laws.

**Deacon** · 04-28-2009, 06:10 PM

OK, I know this is a total noob question, but I just bought my first Jeep and am wondering how the backspacing affects how far out a particular tire sticks out of your fender flares / tire wells. Does it actually affect where the tire rides on the wheel itself, placing it closer or farther from the axle/hub? Or what?

wes19d · 04-28-2009, 06:14 PM

Less backspacing=wheel/tire sticks out further. Backspacing is a measurement from the mounting surface of the wheel to the back lip of the wheel. It does not affect where the tire rides on the wheel.

**Deacon** · 04-28-2009, 06:26 PM

Ah, very nice. I've always preferred the Jeeps' look when the tires stick out a little further. I'm planning on 33x10.5R15 BFG M/T KM2's on Mickey Thompson Classic II's (15x8), which have a backspacing of 3 5/16", which apparently means it can easily take 12.5's should I decide to move to those, and apparently it'll stick out nicely, too

Thanks!

meha11 · 04-28-2009, 06:27 PM

use the information here- http://www.jeepforum.com/forum/showthread.php?t=452871 to fill out the information here- http://www.wheelsmaster.com/rt_specs.jsp

It will tell you everything you want to know from change in mph to clearance dimensions. It is intended for use on cars which it does a great job at, i dont see why it can not be used for a jeep too.

hope you find it useful.

blackattak · 04-28-2009, 06:44 PM

Trust me if you want things to stick out the 33X12.5s on the Mickey Classic IIs will stick out. I just put on he MTZs on those wheels & they throw mud all over the Jeep. Just ordered the Bushwacker 6" Flat Flares to help ( they will still slightly stick ou) remedy this.

05LjNj · 04-28-2009, 07:52 PM

i plan on doing the same setup (33x12.5x15) on cragar soft 8's with 4" BS.. i'm just hoping it doesn't stick out too far past my stock fender flares.. but we shall see.

Strizzy · 04-28-2009, 07:55 PM

I running 4.5BS on my rubi with 305/70/16 and I think it is perfect.
Here's what it looks like:

blackattak · 04-28-2009, 08:15 PM

05LjNj:
My current setup up has the tires out almost 3" from the flares. The Clasics are 3 5/16th bs which is 2 1/4" more than the stock ravines, & the tires 12.5 so 3" wider than stock 30X9.5 that came with the LJ so overall 1 1/2 imches plus 2 1/4 inches so the probably are 3 3/4 inches outside the flares, noticeable but not horrible looking but the mud definitely gets thrown over the Jeep. New Flat Flares I have ordered will give about 3" more coverage than stock so it will hel rectify this issue (but not perfectly). 4" bs would have been better.