i know the whole debate about wheel spacers and their safety issues. Not wanting to open up that can of worms. However I’m not seeing any wheels I particularly like and I don’t know or understand the whole offset thing. At least calculating it. From what I can gather I need an offset that 1.5 wheel spacer on factory wheels would give me. I’m toying with the idea of using spacers for the time being till I can figure out wheels. Currently running a OME J lift with BFG 315’s. Might jump to 37’s in the next year or 2.
Wheel spacers/wheel options? School me.
- Thread starter nonamemtbr
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voodu3
SILVER Star
Reference guide for car wheel and tire dimensions such as size, offset, PCD
This has a calculator and will let you compare tires sized with different wheel offset and backspacing.
This has a calculator and will let you compare tires sized with different wheel offset and backspacing.
If you're going to 37's, you'll want to keep stock backspacing, otherwise the tire will not tuck up in the wheel well. Instead you'll deal with it hitting the fenders.
Going to 37's I would recommend 4.5" to 3.5" backspacing, so depending on your wheel width you would want to choose your negative offset appropriately. For reference I run a 9" wide wheel with a -12 offset (stock backspacing).
I'm currently running 315s on factory wheels with 1.5 inch wheel spacers and love the look. The tires are pretty much flush with the fender flares.
There are two different ways to measure where the wheel mounting surface is in relation to the front and/or back of the wheel.
Backspacing is the distance from the back edge of the wheel to the mounting surface. You can easily measure this by laying the wheel (without a tire on it) face up on the ground and measure from the ground to the flat area on the back of the center hub. Alternatively, especially when there is a tire mounted on the wheel, you can put a straight edge across the back of the wheel and measure to the mounting surface.
Offset is the distance of the mounting surface from the center of the wheel. This is a more difficult measurement to do, because you have to figure out where the center of the wheel is. You can find specs online for factory wheels. Factory 80 wheels are 0mm offset, which means the mounting surface is centered. A positive offset pushes the mounting surface closer to the face of the wheel, a negative offset means the mounting surface is closer to the back of the wheel. Most OEM wheels, especially modern ones, have a positive offset, some aftermarket wheels have a negative offset, which makes them look 'deeper'.
Using the offset measurement is the easiest way to determine how thick your spacers need to be for the desired effect. It's easy with the 80, because the wheels are 0mm offset, so if your replacement wheel has a +32 mm offset you would need a 32mm (1.25" or so) spacer to put the tire at the same place as stock. If you use a 50mm (2") spacer on that wheel, the tires would stick out about 3/4" more than stock.
If you found a wheel with a -32mm (negative) offset, your tires would stick out 1.25" further than stock.
Using the backspace spec is more difficult, since the backspacing changes with the width of the wheel. A stock 8x16" 80 wheel has a 4.5" backspace, because the total width is 9" (8" bead to bead plus the widths of the beads themselves.) However, if you get a 7.5x17" wheel with a 4.5" backspace, the offset is going to be about +12mm. If you found a 12x17" wheel with 4.5" backspacing, the offset would be -50mm. What this means is you can't use backspacing alone to calculate what size spacer to use unless you are comparing the same widths, you have to essentially calculate the offset.
Backspacing is the distance from the back edge of the wheel to the mounting surface. You can easily measure this by laying the wheel (without a tire on it) face up on the ground and measure from the ground to the flat area on the back of the center hub. Alternatively, especially when there is a tire mounted on the wheel, you can put a straight edge across the back of the wheel and measure to the mounting surface.
Offset is the distance of the mounting surface from the center of the wheel. This is a more difficult measurement to do, because you have to figure out where the center of the wheel is. You can find specs online for factory wheels. Factory 80 wheels are 0mm offset, which means the mounting surface is centered. A positive offset pushes the mounting surface closer to the face of the wheel, a negative offset means the mounting surface is closer to the back of the wheel. Most OEM wheels, especially modern ones, have a positive offset, some aftermarket wheels have a negative offset, which makes them look 'deeper'.
Using the offset measurement is the easiest way to determine how thick your spacers need to be for the desired effect. It's easy with the 80, because the wheels are 0mm offset, so if your replacement wheel has a +32 mm offset you would need a 32mm (1.25" or so) spacer to put the tire at the same place as stock. If you use a 50mm (2") spacer on that wheel, the tires would stick out about 3/4" more than stock.
If you found a wheel with a -32mm (negative) offset, your tires would stick out 1.25" further than stock.
Using the backspace spec is more difficult, since the backspacing changes with the width of the wheel. A stock 8x16" 80 wheel has a 4.5" backspace, because the total width is 9" (8" bead to bead plus the widths of the beads themselves.) However, if you get a 7.5x17" wheel with a 4.5" backspace, the offset is going to be about +12mm. If you found a 12x17" wheel with 4.5" backspacing, the offset would be -50mm. What this means is you can't use backspacing alone to calculate what size spacer to use unless you are comparing the same widths, you have to essentially calculate the offset.
Box Rocket
SILVER Star
FWIW, I have been running 1.5" Spidertrax spacers with OEM wheels and my aftermarket SCS wheels for the past 3 years. If you use spacers, get good quality ones. More importantly is having them torqued properly. Don't over tighten the nuts that attach the spacers to the stock lug studs. This can weaken the studs and cause them to fail. Same goes for the studs that are part of the spacers. Obviously you don't want them to be too loose either. Use red Loctite on the spacers and recheck the torque periodically and you shouldn't have any issues. I torque both the spacers and the wheel nuts to 85lb/ft.
Do you use lug or hub centric wheel spacers @Box Rocket
This is not correct in all instances. I run a 1” spacer with stock 80 wheels and SS TRXuS 37x12.5 and it works out perfectly. I never touch anywhere, ever. My experimenting was done in my garage using two floor jacks with the coils removed so I could mimic all possible case scenarios.
The tire I run does have a slightly narrower tread than the typical tread width of a tire having a 12.5” section width. That is exactly why I chose the trxus when I went to 37’s. I recommend these tires
Jason Andrews
Modaholic
I'm running a 17x9 with a 4.5"BS and a 3" wheel adapter/spacer so this nets a total of 1.5"BS on a 9" wheel. I push 600ft/lbs to them in 2wheel drive and turn 42" tires and I haven't died yet. Keeping them tight is key just like keeping your regular lug nuts is.
Yes, when I first installed wheel adapters/spacers I checked them a couple times after breaking them in 100+ mile increments and remove tires and retorque. Once they are tight, they should stay tight. Will s*** hit the fan quicker if wheel bearings, spacers, etc become loose? Yes, but I never had an issue running 1.5" Spidertrax spacers for 10+ years on 37s and 40s so I'm pretty confident and feel totally safe with this setup.
Bottomline is there really isn't any difference from running a custom wheel with a 1.5"BS if you check your spacers are tight periodically, but everyone has heard and seen the photos of the carnage from them failing when they become loose from neglect or incorrect installation procedures.
Diesel sled pulling trucks run wheel spacers and they run motors pushing 1,000s of HP and 2,000s ft/lbs of torque through them and I don't see any of them failing with huge loads placed on them. That is my rationale and 2 cents.
@nonamemtbr - I vote to use the wheel spacers with stock wheels if that is the best option for you! Looks cool that way too!
Yes, when I first installed wheel adapters/spacers I checked them a couple times after breaking them in 100+ mile increments and remove tires and retorque. Once they are tight, they should stay tight. Will s*** hit the fan quicker if wheel bearings, spacers, etc become loose? Yes, but I never had an issue running 1.5" Spidertrax spacers for 10+ years on 37s and 40s so I'm pretty confident and feel totally safe with this setup.
Bottomline is there really isn't any difference from running a custom wheel with a 1.5"BS if you check your spacers are tight periodically, but everyone has heard and seen the photos of the carnage from them failing when they become loose from neglect or incorrect installation procedures.
Diesel sled pulling trucks run wheel spacers and they run motors pushing 1,000s of HP and 2,000s ft/lbs of torque through them and I don't see any of them failing with huge loads placed on them. That is my rationale and 2 cents.
@nonamemtbr - I vote to use the wheel spacers with stock wheels if that is the best option for you! Looks cool that way too!
Great explanation. There are also some handy online wheel spacing calculators that can help you visualize the above concept:
Will They Fit - Online Wheel and Tyre Fitment Calculator
Wheel Offset Calculator
Wheel/Tire Calculators | Custom Offsets
- Thread starter
- #12
I decided to go ahead and buy some 1.5 spydertracs wheel spacers for now. Will be installing them this weekend. I’ll reavaluate once I decide if I want to jump to 37s or not. Just seemed like the logical thing to do.
Anyone else really like the 4Runner honeycomb looking 17" rims with the six hexagons? I love those and wish I had bought them when I got new tires recently. Now I have to wear out my 16" BFG KO2's first, which are sitting on stock rims.
Box Rocket
SILVER Star
I'm not aware of any hub centric spacer options for the 80. Here's the spidertrax spacers I have on my 80. They use conical nuts to center them on the stock lug studs. Wheels for the 80 have a center bore that fits over the outer diameter of the hub, which centers the wheel to a degree but depending on the wheels you have they will either have conical lug nuts to center the wheel properly on the spacer studs, or, in the case of later style 80 factory wheels, they will have flanged lug nuts with a shank that fits in the lug holes of the wheel to center them properly on the wheel studs.
SpiderTrax 80 series Front spacer. These are lug centric spacers.
Spidertrax 80 series rear spacer
In contrast, here is a shot of the Spidertrax spacers used on my Tacoma. These are hub centric spacers. There is a lip on the spacer around the center which will fit inside the center bore of the wheel to center the wheel properly. This lip is not there on 80 series spacers.
Ahh yes I actually did pull one off my fj yesterday and tried to fit them. No dice. The hubcentric spacers from the fj and Tacoma don’t fit the 80 series.
