Which size spacers?

What size spacers?

  • 3/4"

    Votes: 1 7.1%
  • 1"

    Votes: 1 7.1%
  • 1.25"

    Votes: 12 85.7%
  • 1.5" or more

    Votes: 0 0.0%

  • Total voters
    14
Joined
Feb 25, 2017
Messages
355
Location
VA
I'd like to tap the collective wisdom here. I am thinking about getting some spacers to address some slight rubbing. Have read the various POVs here and elsewhere. Spacers would be quality (BORA or Spidertrax), hub centric etc.

Tl;Dr, I think I could go as thin as 3/4"/19mm, but is there a good functional reason to go larger, like 1" or 1.25"?

Wheels = TRD RW (17x8, +50mm offset)
Current tires 295/70R17
Previous tires 315/70R17 (in storage)
Slee KDSS relo

The 315's that PO had rubbed too much, so I mounted the 295's. Thought I was good but noticed sidewalls still rub on the sway bar, but not as much as before.

Purely from a width perspective, I figure the inner sidewalk is about the same as stock since the 10mm offset difference is more than the 5mm the wider side wall intrudes [(295-285)/2=5]. So maybe it's the impact of 33.3" diameter vs 31.5" stock. Anyway, let's say I'd need 10mm to fully eliminate the 295 rubbing.

I'd like to be able to run the 315's on some off-road outings and get some wear out of them. I think I would need another 10mm (315-295)/2= 10mm

So, 10mm to make sure the 295s don't rub, plus 10mm to let me run the 315s = 20mm spacers as sort of a minimum.
3/4" = 19mm, ~= 20mm
1' = 25mm
1.25" = 32mm (thinnest Spider Trax offers).

Not really looking at this for stance, (although the truck does look "tippy" from the front, between taller tire and 2-3" lift).

Does the math and or logic above hold water? Is there a good reason to go with say 1" or 1.25" spacers? I read somewhere (generic) about spacer needing to be thick enough to keep the hub studs from preventing the wheel from fully seating against the spacer.

Many thanks,
DN
 
Joined
Jul 1, 2019
Messages
235
Location
near Kennesaw GA, USA
Others may have more wisdom than I regarding this but what I learned on my 4Runner is these wheels are hub-centric wheels. That’s to say the wheels aren’t centered by a conical shape lugnut but rather a lip on the center of the hub that the rim centers on.

With that as the backdrop I don’t think a .75” spacer wouldn’t work unless it’s hubcentric and that’d require longer studs in the hubs. The Spidertrax are so popular because they work. The spacer is hubcentric and held on by lugnuts and then offers a hubcentric surface for the rim to bolt up with new studs and std lugnuts.

I wanted thinner spacers on my 4Runner and played around... It sucked, I ended up very satisfied with Spidertrax.

The first pic shows what works with hubcentric wheels and lugs. The second pic shows a spacer that would work if you used a lugcentric setup.

Point I’m trying to make is don’t mix apple and oranges. Make sure you have the lugcentric/hubcentric thing sorted.

B2DB31DC-F714-4157-BB66-5B74DC00A6EB.jpeg


7354DB37-8080-489D-83AC-91628E0A9F95.jpeg
 
Last edited:
Joined
Feb 25, 2017
Messages
355
Location
VA
Others may have more wisdom than I regarding this but what I learned on my 4Runner is these wheels are hub-centric wheels. That’s to say the wheels aren’t centered by a conical shape lugnut but rather a lip on the center of the hub that the rim centers on.

With that as the backdrop I don’t think a .75” spacer would work unless it’s hubcentric and that’d require longer studs in the hubs. The Spidertrax are so popular because they work. The spacer is hubcentric and held on by lugnuts and then offers a hubcentric surface for the rim to bolt up with new studs and std lugnuts.

I wanted thinner spacers on my 4Runner and played around... It sucked, I ended up very satisfied with Spidertrax.

The first pic shows what works with hubcentric wheels and lugs. The second pic shows a spacer that would work if you used a lugcentric setup.

Point I’m trying to make is don’t mix apple and oranges. Make sure you have the lugcentric/hubcentric thing sorted.

View attachment 2092006

View attachment 2092007
Thanks for the reply. As I wrote, I would only be going the hub-centric route.
 
Joined
Feb 25, 2017
Messages
355
Location
VA
Rub is one thing, geometry another.
Could use just a wee bit more detail there. Are you referring to scrub radius? Or whether the wheel stuffs inside the fender at full compression? Or something else entirely?
Thx
 
Joined
Apr 27, 2011
Messages
2,979
Location
San Diego
Geometry wise, a .75" spacer is ideal for offset and scrub radius especially when used with large diameter tires. A 1.25" spacer or larger, puts the wheel offset and scrub radius in poor geometry. Enough that you will perceive a difference even if you may not know what to feel for. Not to mention that it also causes more fitment issues than it solves due to the greater swing of the front tire as it turns.

Reason not to do a .75" spacer... structurally, my opinion is there is not enough "meat" in .75" of metal to properly hold a stud in place. It may work, but there is not enough margin in the design IMO to account for extreme use, loads, or perhaps accident avoidance maneuvers. Then consider it might be further taxed with larger tires and heavily built rigs.

For these reasons, I believe a 1" spacer is the best compromise.
 
Last edited:
Joined
Feb 17, 2018
Messages
1,532
Location
Seattle, WA
For that height tire you want something around 45 to 50mm, but due to width of tire it's rubbing.
Ideally there would be a hubcentric small 6mm shim you could pop on, but I've never seen that product.
So putting on 18mm or 25mm more spacer puts you in the 25 to 32mm range. Now you're getting on toward potentially rubbing on the outside fender, again potentially exacerbated by the 295.
It's a pickle for sure.
 
Joined
Apr 27, 2011
Messages
2,979
Location
San Diego
DN, to answer your IM question in regards to how spacers may interact with suspension lift...

Scrub radius doesn't directly relate to suspension lift. There is some interplay in regards to overall setup however.

Specifically, with the front IFS suspension, as the vehicle is lifted, the suspension arms will take on a steeper angle. This does two things: 1) lost roll resistance geometry from the control arms OEM angles 2) reduces the track width which also impacts lateral stability. There are other geometry impacts but those are going to be be what they are without much opportunity to correct.

Can't do much with #1, but fortunately KDSS does mitigate roll to an extent. The lost track width can be restored with spacers to regain some stability. In this way, the spacers are a win-win for clearance, scrub-radius, and regaining lateral stability. Balancing those considerations, a 1" spacer is still a good answer.

1.25" and larger spacers might look good in terms of stance and other considerations, but technically results in too much geometry compromise. Much like a 25mm offset, or eek a 0 offset aftermarket wheel would.
 
Joined
Jul 25, 2011
Messages
870
Location
Raleigh, NC
Geometry wise, a .75" spacer is ideal for offset and scrub radius especially when used with large diameter tires. A 1.25" spacer or larger, puts the wheel offset and scrub radius in poor geometry. Enough that you will perceive a difference even if you may not know what to feel for. Not to mention that it also causes more fitment issues than it solves due to the greater swing of the front tire as it turns.

Reason not to do a .75" spacer... structurally, my opinion is there is not enough "meat" in .75" of metal to properly hold a stud in place. It may work, but there is not enough margin in the design IMO to account for extreme use, loads, or perhaps accident avoidance maneuvers. Then consider it might be further taxed with larger tires and heavily built rigs.

For these reasons, I believe a 1" spacer is the best compromise.
with .75 and shaving studs you still get 8 rotations of lug nuts. So all good
 
Joined
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Messages
2,979
Location
San Diego
with .75 and shaving studs you still get 8 rotations of lug nuts. So all good
That's part of it. The other part the studs that are embedded in the spacer. .75" doesn't leave much space for the stud head and shank. With likely less than the diameter of the stud to fit into. That's the part I don't like.

Most spacers I've seen are made of aluminum. If the .75" spacer was steel, that'd alleviate most of my concern.

This should help visualize the concern. yet this is a 1.25" spacer has 40% more "meat" to work with.

1569772514438.png
 
Joined
Jul 25, 2011
Messages
870
Location
Raleigh, NC
That's part of it. The other part the studs that are embedded in the spacer. .75" doesn't leave much space for the stud head and shank. With likely less than the diameter of the stud to fit into. That's the part I don't like.

Most spacers I've seen are made of aluminum. If the .75" spacer was steel, that'd alleviate most of my concern.

This should help visualize the concern. yet this is a 1.25" spacer has 40% more "meat" to work with.
Remember that you need hub centric wheels spacers. That really holds the wheel safe and avoid putting strain on lug nuts. With hub centric spacers you need proper torque. Extra length stud will not make the difference. With bigger offset you actually put more strain as well on the hubs and with wheel sticking out you will cause paint chips on your fenders.
 
Joined
Apr 27, 2011
Messages
2,979
Location
San Diego
Remember that you need hub centric wheels spacers. That really holds the wheel safe and avoid putting strain on lug nuts. With hub centric spacers you need proper torque. Extra length stud will not make the difference. With bigger offset you actually put more strain as well on the hubs and with wheel sticking out you will cause paint chips on your fenders.
Hub centric is to ensure wheel centering when installing. Once torqued, there's little to no support provided by the hub centric lip. I don't disagree with you on hubs taking more strain with larger spacers. That's true for larger diameter tires and heavier rigs too, to a more significant degree.

The point I'm making about meat is this. The area in red is what's available for lug engagement and support on a .75" spacer, that amounts to something like .5". Much less than what you see here on a 1.25" spacer diagram. Not that it doesn't work and that many people are using .75" spacers.

For me, I don't like that minimal margin of material, especially for my uses towing at the 14,645lb GCWR. Hence my recommendation for a 1" spacer.


1569860808601.png
 

Willy beamin

SILVER Star
Joined
Nov 11, 2013
Messages
3,819
Location
louisville, KY
I had the same idea too. Good luck finding a longer stud for a 10mm spacer. I had Wheel Adapters, Wheel Spacers, Hub Rings, and much more! | Motorsport Tech make me a 10mm spacers set a few years back. Those 10mm spacers never got mounted. Motor sport sent me some extended studs which would not seat in the hubs. We tried others with the same outcome. Those 10mm spacers sit in box in my garage collecting dust. Solution was I had motorsport make the .75" bora spacers, which have held up just fine for a few years now. I run a 12.5" width tire on Rock warrior wheels and clear the rear of my wheel well even when my tires are stuffed.
 
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