Wheel Offset and backspacing question

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Laredo Matt
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Wheel Offset and backspacing question

Post by Laredo Matt »

I found a set of 17" raceline wheels for my build and have what may be a dumb question but ...

What offset were stock wheels from factory?

I'll be running 33s and don't want the tires to extend past the fender wells (83 Laredo WT). I figured best bet is to get same offset as factory.

I kinda assume 0 offset from factory but that may be totally wrong. If so, is it safe to assume 0 offset (or whatever matches factory) is an agreed upon standard so all wheels, regardless of manufacturer, fit the same for a given offset/backspacing.

TIA
Matt
83 Cherokee Laredo WT
L8T 6.6L, 6L90
GEN III LS Swap (LM7 block)
4L60E

Mreuther12
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Re: Wheel Offset and backspacing question

Post by Mreuther12 »

I’m running Raceline Boost 17x9 -12 offset. I believe that stock backspacing is around 3.75” but you are going to have a tough time finding a modern wheel with that backspace


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tgreese
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Re: Wheel Offset and backspacing question

Post by tgreese »

Yes, that's right. Plenty of 15" wheels with 3.5" or 3.75" backspacing. Suggest you use the search engine for wheels at Summit (or maybe Jegs?) to see what's available.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
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Topic author
Laredo Matt
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Re: Wheel Offset and backspacing question

Post by Laredo Matt »

Mreuther12 wrote: Sun Dec 19, 2021 9:40 pm I’m running Raceline Boost 17x9 -12 offset. I believe that stock backspacing is around 3.75” but you are going to have a tough time finding a modern wheel with that backspace


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I was looking at the Boost originally but leaning toward the Krank.

The 17x9 Krank has a 4.52" backspacing with a -12 offset, basically the same as your wheel.

My current wheels, best as I can tell, has 4.125" back spacing and -12 offset.

If I'm figuring correctly, that would cause the Krank or Boost to sit deeper inside the wheel well about 1/2" more than my current wheel. Look wise I think it would be fine but I'm concerned about brake component clearance. I have direct fit replacement discs and calipers so don't know if that's a concern.

Do you have a picture of your rig with the wheels you'd d mind sharing? Do you have factory discs with up front and is there any issue?

Also, I measured the bore on my current wheels and it is 3.5" or ~89mm. The Krank is 106mm and Boost is nearly 109mm. I thought the wheels required a larger bore to clear the hubs but that seems much larger than needed?

TIA
Matt
83 Cherokee Laredo WT
L8T 6.6L, 6L90
GEN III LS Swap (LM7 block)
4L60E

Mreuther12
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Re: Wheel Offset and backspacing question

Post by Mreuther12 »

Wheels clear the front discs plenty of room. As for the hub bore, this has to do with modern hub size. I spent a ton of time researching wheels trying to find something that would check all the boxes, but never came across anything short of custom beadlocks.

There is a company that I saw makes a hub spacer that would fit over our hubs and the inside the 109mm hub bore on the wheels. I reached out on Instagram they want $289 for the set.

My build thread has pictures of the wheels on the waggy toward the end. I need to do an update at some point.

https://www.fsjnetwork.com/forum/viewtopic.php?t=17906


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1970 Wagoneer
- Buick 350 Dauntless V8, TA Performance Stage 1 Intake, Holley Sniper, Holley Hyperspark, Electric Fan, Aluminum Radiator
- 76 J10 D44 w/ OX Lockers Front & Rear

WT Conversion in progress...

Topic author
Laredo Matt
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Location: Washington

Re: Wheel Offset and backspacing question

Post by Laredo Matt »

Mreuther12 wrote: Mon Dec 20, 2021 8:19 pm Wheels clear the front discs plenty of room. As for the hub bore, this has to do with modern hub size. I spent a ton of time researching wheels trying to find something that would check all the boxes, but never came across anything short of custom beadlocks.

There is a company that I saw makes a hub spacer that would fit over our hubs and the inside the 109mm hub bore on the wheels. I reached out on Instagram they want $289 for the set.

My build thread has pictures of the wheels on the waggy toward the end. I need to do an update at some point.

https://www.fsjnetwork.com/forum/viewtopic.php?t=17906


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I didn't realize it but looking at your build, I think you sent me a PM with a picture of the jeep a while back when I was asking about wheels when I started.

That's steep for a set of hub spacers. The wheels look good enough without it.

thanks for the feedback...cheers
Matt
83 Cherokee Laredo WT
L8T 6.6L, 6L90
GEN III LS Swap (LM7 block)
4L60E

Topic author
Laredo Matt
Posts: 331
Joined: Fri Jan 08, 2021 3:32 pm
Location: Washington

Re: Wheel Offset and backspacing question

Post by Laredo Matt »

tgreese wrote: Mon Dec 20, 2021 9:25 am Yes, that's right. Plenty of 15" wheels with 3.5" or 3.75" backspacing. Suggest you use the search engine for wheels at Summit (or maybe Jegs?) to see what's available.
I' started looking for 15s a while back but choices were limited compared to larger wheels. It seemed like everything I liked was only available in 17s and up. The more I looked the more I was confident I wanted 17s. You know, more air flow to help cool brakes blah blah rationalizations... fact is I just like the look and that heavily influences some decisions :)
Matt
83 Cherokee Laredo WT
L8T 6.6L, 6L90
GEN III LS Swap (LM7 block)
4L60E

Mreuther12
Posts: 84
Joined: Fri Oct 04, 2019 10:45 am
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Re: Wheel Offset and backspacing question

Post by Mreuther12 »

The hub spacer would also take some of the load off off the wheel studs, I see a benefit in that regard.

They are still expensive


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- Buick 350 Dauntless V8, TA Performance Stage 1 Intake, Holley Sniper, Holley Hyperspark, Electric Fan, Aluminum Radiator
- 76 J10 D44 w/ OX Lockers Front & Rear

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Yeller
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Re: Wheel Offset and backspacing question

Post by Yeller »

In my opinion it really is a mute point, very few wheels oem or otherwise have ever been hub centric and run without issue. There are a few vehicles designed with hub centric wheels but these most certainly were not.
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AccrateDelivery
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Re: Wheel Offset and backspacing question

Post by AccrateDelivery »

Yeller wrote: Tue Dec 21, 2021 4:54 pm In my opinion it really is a mute point, very few wheels oem or otherwise have ever been hub centric and run without issue. There are a few vehicles designed with hub centric wheels but these most certainly were not.
Agreed.
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tgreese
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Re: Wheel Offset and backspacing question

Post by tgreese »

Just fyi, MOOT, not MUTE. Entirely different. Pronounced differently too - moot rhymes with root, mute rhymes with cute. Moot means irrelevant or inconsequential. Mute means dumb, like deaf and dumb. Or to make silent. Or the thing that goes in the bell of a brass instrument to change the sound.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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Stuka
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Re: Wheel Offset and backspacing question

Post by Stuka »

Yeller wrote: Tue Dec 21, 2021 4:54 pm In my opinion it really is a mute point, very few wheels oem or otherwise have ever been hub centric and run without issue. There are a few vehicles designed with hub centric wheels but these most certainly were not.
I actually cannot think of a single late model passenger vehicle that doesn't have hub centric wheels. Even the stock steelies on my '75 Cherokee were hub centric.
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AccrateDelivery
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Re: Wheel Offset and backspacing question

Post by AccrateDelivery »

They must be 'moot-ants'? lol

When you go 'aftermarket' wheels, you pretty much have to let hub-centric take a back seat to 'fit the bolt pattern' and offset. IT's just too limited in selection to expect to find the best of all 4 worlds in one wheel.
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