Scrub radius question (1 Viewer)

[highfructose]

I’m trying to figure out an optimum upgrade from stock when my wheels go bad...I’ve seen many Toyota wheels that end up flaking and going to crap in the long run.

right now my 20’s on my lx570 look good but there are some places where it looks like they’re going to break down at some point.
I’m curious what the optimum offset would be to maintain scrub radius given taller than Spec’d tires.
Specifically I’m looking at a 275 70 r18 (33.2”) like in the attached but perhaps instead of with the evo corse’s in the photo, shifting to a volk te37. Weight wise, with the volk’s and that size tire, the wheel tire combo will actually be just a bit lighter than stock.
What offset might I be looking for for a 33.2” tire to maintain the proper scrub radius?

 

[bloc]

There was some discussion of the volks not being strong enough for our application.. or at least in 17”. Is that any better in 18? Otherwise they seem like awesome wheels

 

[highfructose]

There was some discussion of the volks not being strong enough for our application.. or at least in 17”. Is that any better in 18? Otherwise they seem like awesome wheels

They may mot be strong enough. I guess I would need to find that out.
I actually prefer how the evo corse’s look....so that might be the direction to plan on going, even though they’re slightly heavier.
Anyone know the exact weight of the 18” evo corse’s? I see 11-13.5 kg but no specifics for American versions.

 

[TeCKis300]

Back of the napkin math says optimal offset for a 33.2" tire would be +45mm.

Wonder if it's the salty Florida air that wrecks havoc on wheel finishes? Can't say I've seen many finishes fail on stock wheels here in CA.

 

[highfructose]

Back of the napkin math says optimal offset for a 33.2" tire would be +45mm.

Wonder if it's the salty Florida air that wrecks havoc on wheel finishes? Can't say I've seen many finishes fail on stock wheels here in CA.

It might be. The population centers here are on the coasts for the most part...so most of the used Toyota’s and Lexus’s I shopped also, likely, came from those areas.
And thanks!

 

[gaijin]

Specifically I’m looking at a 275 70 r18 (33.2”) like in the attached but perhaps instead of with the evo corse’s in the photo, shifting to a volk te37. Weight wise, with the volk’s and that size tire, the wheel tire combo will actually be just a bit lighter than stock.
What offset might I be looking for for a 33.2” tire to maintain the proper scrub radius?

Here's a good online tool to play around with scrub radius: Rim & Tire Size Calculator

It indicates an offset of around +52mm would yield a zero scrub radius for your 275/70R18 tires.

HTH

 

[TeCKis300]

Here's a good online tool to play around with scrub radius: Rim & Tire Size Calculator

It indicates an offset of around +52mm would yield a zero scrub radius for your 275/70R18 tires.

HTH

Negative. While that calculator is useful, it's not accurate as I don't see provisions to calibrate for our vehicles kingpin angle.

We know stock offset with stock wheels. We know validated fitment for Rock Warriors at +50mm and 32.7" tires. That would suggest it's not correct for a larger diameter tire to require a +52 offset.

 

[grinchy]

I thought I found the kingpin info in one of the FSM addendums, I recall posting, but can’t find it now. Ugh. I run 35mm effective offset for 35” tires, it feels pretty neutral so I’d say I’m not far off. I too think a 33” would be between 50mm and 40m. You could plot a line for the stock and rock warrior fitments and make some educated guessing.

 

[gaijin]

Negative. While that calculator is useful, it's not accurate as I don't see provisions to calibrate for our vehicles kingpin angle.

We know stock offset with stock wheels. We know validated fitment for Rock Warriors at +50mm and 32.7" tires. That would suggest it's not correct for a larger diameter tire to require a +52 offset.

Wrong. You are assuming the LT285/70R17 tires on the RW wheels with +50mm offset are Zero scrub radius - you don't know that.

I'm also not suggesting that Zero scrub radius is the most desirable goal.

All I'm suggesting is that the calculator I linked to would be a good tool for the OP to use in order to better understand the effect of differing offset in his proposed application.

Sorry, but you're not dragging me down another rat hole with this one

 

[TeCKis300]

Wrong. You are assuming the LT285/70R17 tires on the RW wheels with +50mm offset are Zero scrub radius - you don't know that.

I'm also not suggesting that Zero scrub radius is the most desirable goal.

All I'm suggesting is that the calculator I linked to would be a good tool for the OP to use in order to better understand the effect of differing offset in his proposed application.

Sorry, but you're not dragging me down another rat hole with this one

LOL, not following factory validated specs for once? You're down the rabbit hole alone on this one.

 

[gaijin]

LOL, not following factory validated specs for once? You're down the rabbit hole alone on this one.

Nice try - bye.

 

[dubaicruiser]

Here's a good online tool to play around with scrub radius: Rim & Tire Size Calculator

It indicates an offset of around +52mm would yield a zero scrub radius for your 275/70R18 tires.

HTH

Don't want to hijack, But I am planning to get 295/70/R18 and the calculator says this: Stock rims, 2014 vxr with 1.5inch lift.

Negative scrub radius (about -11 mm). Scrub radius will be changed by -11 mm, this may affect the car's handling. Please check manufacturer recommendations. Please be aware that calculated value is approximate.

What does this mean?

 

[grinchy]

Found it again.

Standard Steering Axis Inclination (Unloaded Vehicle) SUSPENSION PACKAGE OPTION STEERING AXIS INCLINATION: REFERENCE Active Height Control STD Steering Axis 13°00' (13.00°)

Note I'm in the LX570 guide for 2009.

 

[grinchy]

and now for the 200 TLC 2009 year
Standard Steering Axis Inclination (Unloaded Vehicle) STEERING AXIS INCLINATION: REFERENCE Steering Axis 12°51' (12.85°)

 

[grinchy]

Don't want to hijack, But I am planning to get 295/70/R18 and the calculator says this: Stock rims, 2014 vxr with 1.5inch lift.


What does this mean?

racing aspirations » What is Scrub Radius

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