Spacers, scrub radius, etc?

[TeCKis300]

Ah, sorry, I don't know the actual angle. It's built into the geometry of the suspension and it's not really something that can be adjusted. Could physically measure it as it is the imaginary line from the UCA ball joint to the LCA ball joint.

 

[luke27617]

As a point of reference, my stock 20x8.5" 60mm offset wheel, with 1" spacer (~34mm effective offset), and 305/55/20 (33.2"x12.3") tires. Pretty flush with the side of the body and I've not had any issue with rocks kicking up damaging the paint on the vehicle. Or the trailer I tow.

You can also see where it's helped keep terrain off my side steps in particular, because the tire is the widest point by a tad. I would have sustained more significant damage if my tires were inset in a pinch or side sliding situation.

The takeaway isn't just taller. Many times the compromise in fitting a larger tire is that one can go taller if compromising some width. In the 200-series, one can go taller and wider, up to 34s rather easily. Definitely without a need to downsize any dimension. My objective is to have the rig do everything better. Not to trade better off-road performance for significantly compromised road performance. Especially as that's where I do 99% of my driving.

Thanks for posting feedback. No rock chips on inner fender metal work? It seems the rear as an example goes .75" deep. That is a lot of exposed metal.

 

[TLCLVR]

I'm particular to vehicle handling and dynamics (I use to race on tracks). Which makes scrub radius important to me. Yet practical concerns need to be balanced as well, including clearance for wider tires, and availability of spacer sizes.

I would say +30mm is in the range that is okay for the 200-series, especially when paired with larger diameter tires. Much below that, other practical concerns such as tire swing causing interference and steering pull become issues.

I run a ~35mm offset with my stock 20x8.5 +60mm wheels, 1" spacers, and 33.2" x 12.3" tires. I can feel a bit of pull and scrub, especially when fully laden and towing, with pedal to the metal climbing 7%+ grades. I'm not lifted at all, and the steering will pull in these conditions. Ideally, I would have preferred an offset of ~45mm.

The market also has .75" spacers which would have put me at a more ideal offset. Yet IMO, .75" spacer adapters are not safe, as there's simply not enough "meat" for a .75" piece of metal to carry lugs IMO. Which is why I'm using 1" spacers.

From a scrub radius and fitment perspective, a 1" spacer is preferred over a 1.25" spacer when used with stock wheels.

@TeCKis300, Reading through this to ensure I have the right sized spacers and scrub with upcoming new 34"(285/70R18) tires. My understanding was that the 20x8.5" LX wheel has an offset of +45mm and the Tundra 18x8" stock wheel has an offset of +60mm. Did I get that wrong somehow?

Update (3/7/20): Went out and measured my '13 LX570 20" wheels and they are indeed a +60mm offset. Thanks again to @TeCKis300!

 

[bryson]

Everything I find online shows that the OEM LX 20" wheels share the same +60 offset that the OEM 18" LC/Tundra/Sequoia wheels have.

 

[Angelo1]

Would I be better off running a 295/70/18 or a 285/75/18 with a +18 off set wheel. I don’t want my bead lock ring to scrub on curbs or rocks if it’s going to sit flush with the tire but I also want to prevent any kind of additional bearing wear. My current 35” tire loves rubbing up against the KDSS post and bar

 

[terdrocket]

Would I be better off running a 295/70/18 or a 285/75/18 with a +18 off set wheel. I don’t want my bead lock ring to scrub on curbs or rocks if it’s going to sit flush with the tire but I also want to prevent any kind of additional bearing wear. My current 35” tire loves rubbing up against the KDSS post and bar

Keep in mind that with either of those sizes your sidewall will be over 8" tall, taller than any typical curb face. As for rocks...

 

[grinchy]

Would I be better off running a 295/70/18 or a 285/75/18 with a +18 off set wheel. I don’t want my bead lock ring to scrub on curbs or rocks if it’s going to sit flush with the tire but I also want to prevent any kind of additional bearing wear. My current 35” tire loves rubbing up against the KDSS post and bar

Spend some time with a wheel size calculator that calculates scrub to see how t he different total offset affects scrub.

 

[Angelo1]

Spend some time with a wheel size calculator that calculates scrub to see how t he different total offset affects scrub.

Yeah, I’ve been doing that and it seems the 295/70/18 might work....barely. I am having my local tire shop try a Nitto terra grappler 295/70/18 they have in stock on the front driver side to see if it will work. Otherwise, I know a 285/75/18 will.

 

[grinchy]

Yeah, I’ve been doing that and it seems the 295/70/18 might work....barely. I am having my local tire shop try a Nitto terra grappler 295/70/18 they have in stock on the front driver side to see if it will work. Otherwise, I know a 285/75/18 will.

In general width is harder to deal with than diameter.

 

[Angelo1]

In general width is harder to deal with than diameter.

True. My 12.50 width tire even on a 18+ offset is not even ideal unless I did a Tundra upgrade and that’s not happening. I plan on keeping the rig for many years and don’t need to add any more variables.

 

[TLCLVR]

Spend some time with a wheel size calculator that calculates scrub to see how t he different total offset affects scrub.

Grinchy, any calculators you can recommend? The one’s I’ve found require some baseline info on your stock scrub or kingpin angle, neither of which I’ve been able to verify.

 

[linuxgod]

Try this link

Rim & Tire Size Calculator. Custom Offsets

Tire Tech Information - The Wheel Fitment, Tyre Stretch, Rolling Radius and Speedometer Error Calculator. Play with specs, try different settings, compare results

www.wheel-size.com

Short summary is roughly +60 stock offset on 31s, +50 on 33s, +40 on 35s.

Lower offset will add a bit of squirreliness to hard acceleration and braking. I haven't found there to be a significant impact at +25 though. Differences in left/right side vehicle (fender) height and/or lift will have much more noticeable impact. It would be different if you were on a track with a Ferrari running at 9/10 but on a highway SUV don't let the offset debate rule your decision.

That said I run +25 on 34s because I wanted more suspension clearance - and I still rub the KDSS and sway bar slightly at full lock on 34x11.5.

 

[grinchy]

Rim & Tire Size Calculator. Custom Offsets

Tire Tech Information - The Wheel Fitment, Tyre Stretch, Rolling Radius and Speedometer Error Calculator. Play with specs, try different settings, compare results

www.wheel-size.com

Calculates scrub assuming you enter in a stock wheel tire and offset and that assumes stock is 0 scrub

 

[silverhorse]

So I assume running a 0 offset wheel with no spacer with an 11.5 wide tires still going to put you too far out? Meaning tire may hit the fender during articulation?

 

[grinchy]

So I assume running a 0 offset wheel with no spacer with an 11.5 wide tires still going to put you too far out? Meaning tire may hit the fender during articulation?

There’s a low offset thread around. I’ve got 275/80r18 35s at 35mm and I wouldn’t want to be any less offset, but like many things it has been done.

 

[TLCLVR]

Try this link

Rim & Tire Size Calculator. Custom Offsets

Tire Tech Information - The Wheel Fitment, Tyre Stretch, Rolling Radius and Speedometer Error Calculator. Play with specs, try different settings, compare results

www.wheel-size.com

Short summary is roughly +60 stock offset on 31s, +50 on 33s, +40 on 35s.

Lower offset will add a bit of squirreliness to hard acceleration and braking. I haven't found there to be a significant impact at +25 though. Differences in left/right side vehicle (fender) height and/or lift will have much more noticeable impact. It would be different if you were on a track with a Ferrari running at 9/10 but on a highway SUV don't let the offset debate rule your decision.

That said I run +25 on 34s because I wanted more suspension clearance - and I still rub the KDSS and sway bar slightly at full lock on 34x11.5.

Excellent. Same site I was using, just didn't want to wrongly assume stock was 0.

Thanks!

 

[Pskhaat]

275/80r18

Who makes those?

 

[Pskhaat]

Rim & Tire Size Calculator. Custom Offsets

Tire Tech Information - The Wheel Fitment, Tyre Stretch, Rolling Radius and Speedometer Error Calculator. Play with specs, try different settings, compare results

www.wheel-size.com

Calculates scrub assuming you enter in a stock wheel tire and offset and that assumes stock is 0 scrub

Alas, it does take some assumptions on KPI. I'm still unsure what the various Cruiser KPIs are.

 

[Pskhaat]

the 295/70/18 might work.... know a 285/75/18 will.

Why would you not go for a larger aspect ratio tire if you have the option?

 

[Angelo1]

Why would you not go for a larger aspect ratio tire if you have the option?

I’m going to try a 295/70/18 next week but it must don’t rub up against the KDSS. I don’t mind if it barely touches.