Offsets, Backspace, and other wheel info

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Aldo

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Hi,
Would you please tell me what rims are good for my stock KJ 2007?
I have mfg mt km2 235/70/16. I bought (like a stupid) a set of 4, 8x16, offset -30 (didn't know what is negative offset) and cannot use them.
Thanks
 

Jim McClain

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Here's a question that hasn't been asked, at least not in this thread: What is the smallest acceptable inside diameter of a wheel? In other words, what is the outside diameter of the brake disk and caliper (not just the disk)?

I have found wheels I like a lot that have an inside diameter of 13.47". They are 16x7" 5on4.5 4"bksp. If that's too small, I can get the same wheel in a 17x7 5on4.5 4.5"bksp and add a half-inch spacer to get it back to 4" back space. The larger wheel has an inside diameter of 15.47".

Can any of you take a measurement of the brakes? Measure from center of hub to top most portion of the caliper, then multiply by 2.

Thanks,

Jim
 

dude1116

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Here's a question that hasn't been asked, at least not in this thread: What is the smallest acceptable inside diameter of a wheel? In other words, what is the outside diameter of the brake disk and caliper (not just the disk)?

I have found wheels I like a lot that have an inside diameter of 13.47". They are 16x7" 5on4.5 4"bksp. If that's too small, I can get the same wheel in a 17x7 5on4.5 4.5"bksp and add a half-inch spacer to get it back to 4" back space. The larger wheel has an inside diameter of 15.47".

Can any of you take a measurement of the brakes? Measure from center of hub to top most portion of the caliper, then multiply by 2.

Thanks,

Jim

Never heard of a 16" wheel that doesn't work...so your wheel should work.

Although that also only answers half of your question. I believe some 15's fit with a hair width of clearance between the wheel and the caliper.
 

Jim McClain

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I'd feel safer with an actual measurement. It may seem silly to not reveal the brand and style of the wheel, but I'd kinda like to be the first guy on the block, so to speak, to have these wheels on a KJ. Suffice it to say, it's not your standard 16" wheel. And I'm hoping the 16-incher will work because the selection of tires is much greater. But if the ID of that wheel is too small, then my only hope would be the 17-incher - and there's no guarantee that it will work either, unless I know the diameter of the brake disk and caliper.
 

tommudd

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I'd feel safer with an actual measurement. It may seem silly to not reveal the brand and style of the wheel, but I'd kinda like to be the first guy on the block, so to speak, to have these wheels on a KJ. Suffice it to say, it's not your standard 16" wheel. And I'm hoping the 16-incher will work because the selection of tires is much greater. But if the ID of that wheel is too small, then my only hope would be the 17-incher - and there's no guarantee that it will work either, unless I know the diameter of the brake disk and caliper.

I've yet to hear of a wheel not working ( 16 inch) most 15 inch stock type wheels won't work due to how they are made in the back, that's why aftermarket will in most cases but stocker won't.
As far as what the calipers measure I have that somewhere just can't lay my hands on it.
Funny story, we built a 50 Chevy pickup for my buddy, he wanted a certain size wheel which I said wouldn't fit , we built it, he drove it home a week later he arrived at my place with his new wheels. Boasting that I didn't know crap and see they worked.
Well we had used a front clip from a camaro and used the stock brake setup etc that came with it till we got all the bugs worked out. After we installed all new hardware, calipers, pads , rotors a few weeks later his new wheels wouldn't fit. That little extra width of the new pads was enough so that the wheels wouldn't turn :happy175::happy175:
But I also did the same thing years earlier on a lowered GMC pickup I build so knew he'd have issues
 

Jim McClain

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The friendly folks at Les Schwab were kind enough to invite me into a shop bay on a quiet day so they could help me take some measurements.

After removing the front-left wheel (my online research concluded that the front brakes are slightly larger than the rear in most cases), measuring from the center of the hub to the outer most portion of the calipers showed 7⅜", which equals a 14¾" diameter. That means a wheel with an inside diameter of 15" or more should work (provided it also meets other criteria for fitment).

I also had the technician measure the hub protrusion, which translates to the center bore hole of a wheel. That measurement is 2.8".

Please keep in mind my KJ is a 2005 Limited. I don't know if these measurements would be different on other models or years of KJs.

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The reason these measurements were important to me is because I found a type of wheel that I really like. There are 2 basic styles of this type, but only one comes in a 16x7 5/4.5 4"bs. Unfortunately, that wheel only has an inside diameter of 13.47". However, that same style also comes in a 17" wheel - 17x7 5/4.5... but with a 4.5" backspace. It has an inside diameter of 15.4", so it should fit over the disk brakes and calipers of a KJ.

Questions for those of you with experience:
  1. Will a 17x7 5/4.5 4.5"bs wheel work without using a half-inch spacer?

  2. And if so, what is the largest tire that would fit on a 3" lifted KJ?

  3. Finally, if a half-inch spacer would be necessary to prevent the tires (and maybe even the wheel itself) from scraping the suspension components or inside body parts, is that small a spacer such a bad thing?

Thanks for your guidance.
 

tommudd

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Just run it without a spacer,
1/2 inch spacer would be very bad
you would either have almost no threads holding it on
or you would have to cut the end of the studs off
for tire size just look for 17 inch tires in 30 inch tall range
 

Jim McClain

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Thanks Tom. The second style in that wheel type I mentioned has a back space of 5¼". There are high quality, hub centric 1¼" spacers available that would not require cutting into the threads of the studs and would bring the back spacing out to the 4" Jeep engineers determined was optimal.

Considering that the use of a spacer in this particular case is actually an adapter designed to bring the wheel geometry back into specs, not to push the wheel out farther for looks or a false sense of better handling, do you think this might be a viable option? Granted, I could just shop for a wheel that has the proper back spacing, but those I do like are still a very distant second to the wheels that need some adapting.

I hope you understand I'm not looking for a it's-your-money, throw up your hands in disgust response. By the same token, I am not looking to hear the standard boilerplate response either. I have tried very hard to do the research. But I'm still stuck with an artist's head. I want the Jeep to have a unique look, but I still want it to be safe and functional. I look to the wisdom of those I have come to trust in the year I've been a member here.

Thanks,

Jim
 

patandted

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This has probably been asked many times before but I am buying a 2007 liberty/cherokee in the UK its the 2.8 diesel one and it has these 17" wheels that you cannot get decent tyres for I sold my 2001 XJ last year and I noted that the 16" alloys on that was still in good condition can anyone tell me if the 2000/1 XJ 16" alloys will fit my KJ to replace the 17" ones.
 

tommudd

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This has probably been asked many times before but I am buying a 2007 liberty/cherokee in the UK its the 2.8 diesel one and it has these 17" wheels that you cannot get decent tyres for I sold my 2001 XJ last year and I noted that the 16" alloys on that was still in good condition can anyone tell me if the 2000/1 XJ 16" alloys will fit my KJ to replace the 17" ones.

Yes the 16 inch wheels from a XJ will work, same as stock KJ wheels
 

lfhoward

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Thanks for putting that diagram up there. A related term I’ve heard is backspacing. How would backspacing be measured on this diagram?

also, which side of the wheel in the diagram is inboard to the vehicle? L or R?
 

tommudd

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Thanks for putting that diagram up there. A related term I’ve heard is backspacing. How would backspacing be measured on this diagram?

also, which side of the wheel in the diagram is inboard to the vehicle? L or R?
Right side would be the face or what you see when mounted on a vehicle
Backspacing is measured from the back part of the wheel, ( where the tire sits ) not on the outside " rim " of the wheel where weights are attached
For example a MOAB is 8 inches wide with 5 inches of backspacing , so from the flat part that sits against the hub to the backside of the wheel is 5 inches
from where it attaches to the hub to the front would be 3 inches of course
 

mercdudecbr600

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Info on Stock Wheels:

Bolt Pattern: 5x4.5" or 5-114mm
Backspace: 5.5" (might be a hair larger than this actually)
Offset is 41mm ( I know the chart says 38, but I found 41 from a tire vendor that said the factory wheels are 41 )
Wheel size is 16 x 7
Stock Tire Size ranges, but 235/70R16 is most common.


If anything seems wrong please correct me.

Bennett

Measured to the outer lip, backspacing is closer to 5 3/4". If you measure to the tire bead, it's about 5 1/4"
 

Redonthehead

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Wish I had found this site sooner cuz I think I messed up. Bought a set of 245/75/17 tires with wheels from a 2015 Wrangler for my 2005 KJ Renegade. Of course 1st thing I realize is the new wheels are 5x5. Before I look at adapter/spacers, etc., can anyone tell me if these wheels & tires are just not going to work on my KJ? I'm not opposed to lifting (up to 2.5") cuz I probably need new shocks and springs anyway... Any help is much appreciated.
(wheels 7.5" wide, 5.75" backspace if I measured right)
 
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tommudd

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Wish I had found this site sooner cuz I think I messed up. Bought a set of 245/75/17 tires with wheels from a 2015 Wrangler for my 2005 KJ Renegade. Of course 1st thing I realize is the new wheels are 5x5. Before I look at adapter/spacers, etc., can anyone tell me if these wheels & tires are just not going to work on my KJ? I'm not opposed to lifting (up to 2.5") cuz I probably need new shocks and springs anyway... Any help is much appreciated.
(wheels 7.5" wide, 5.75" backspace if I measured right)
will not work , tires or wheels either one
 

Redonthehead

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Thanks Tom. Glad to see you back.
I sold the Wrangler set for what I had in it and just replaced my tires with stock sized tires (for now).
Too many other things to spend money on: rusty rockers & door bottoms; sound system; roof rack; ....
 

EricNorton

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I'm looking into getting new wheels to fit bigger tires and widen my stance for the offset on the rim would it be better to get 0 off-set or something more severe such as -6 or -12 offset if I'm able to find styles I like to be able to fit 265/75-r16 with doing around a 3.5 in lift
 
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tommudd

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I'm looking into getting new wheels to fit bigger tires and widen my stance for the offset on the rim would it be better to get 0 off-set or something more severe such as -6 or -12 offset if I'm able to find styles I like to be able to fit 265/75-r16 with doing around a 3.5 in lift
7 inch wide with 4 inches of backspacing when lifted
Are you going to regear to 4.10s ?
If not its going to be a dog with that size tire, transmission will have to work harder , run hotter due to continually shifting
plus you will lose 5 to 6 MPG at least
 

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