MT's vs AT's, 17's, 18's vs 20's discussion

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Augster

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Lets talk about offset for a sec: lets presume we're using a 9 inch wide wheel, 35" tire. What are the main reasons Raptor guys seem to like their wheels tucked in so tight? Clearance for 37" tires so they don't hit the fenders? Less stress on bearings and ball joints? Steering?

From my research, the most likely reason is because some positive offset (more backspacing) has the least chance of having the outer tire edge contact the lower rear portion of the fender liner near full lock to the left under articulation. Right behind it is the pinch weld between the floorboard and driver's side panel, which sticks out about an inch forward. One solution to avoid rubbing is to fold over and flatten the pinch weld with a hammer, or just cut off, then tack the portion of the fender liner straight onto the floorboard.

You can't go too far deep inside (more positive offset) without the inner sidewall contacting the UCA's...

I heard to run the RPG UCA's with the massive 1.5" upper ball joint, you need a wheel with less than 5" backspace? I might get those. To get that 5" BS you need a 13mm offset, and that pushes the outer wheel lip out just a hair over 1" What's the big deal about that? FWIW, I don't mind 1" of poke cuz I'd like to get extended Bushwhacker Pocket Flares for the added protection and the blacker color and hardware look. Don't like my grey stock flares with a tux black screw.

Are you sure that RPG's have 1.5" uniballs? From the description on their website of their billet UCA's, it's 1"...

Screenshot 2024-01-23 at 5.01.16 AM.png

SVC billets are 1.5" uniballs. But some have recommended the Icon UCA's because of their fully sealed and greaseable Delta upper ball joints, which is what I'm leaning towards, if not the SVC's. The GS 460's I run with both use Icon UCA's.

I don't know where you're getting info stating you need -13mm offset to clear aftermarket UCA's, but SVC's UCA description specifies minimum 0 offset:

Screenshot 2024-01-23 at 5.18.33 AM.png

As I mentioned in a previous post, I'm running 20x9+1mm and 35x12.5 and have no rubbing whatsover under full articulation and full lock in either direction, with plenty of clearance for an aftermarket UCA; it will definitely clear the Icons, I'm confident it will clear SVCs as I doubt 1 itty bitty millimeter will make any real-world difference with all the sidewall flexing that may occur that I'm sure SVC has allowed some generous clearance gap when determining a mimimum offset.
 
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FishFreak

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From my research, the most likely reason is because some positive offset (less backspacing) has the least chance of having the outer tire edge contact the lower rear portion of the fender liner near full lock to the left under articulation. Right behind it is the pinch weld between the floorboard and driver's side panel, which sticks out about an inch forward. One solution to avoid rubbing is to fold over and flatten the pinch weld with a hammer, or just cut off, then tack the portion of the fender liner straight onto the floorboard.

You can't go too far deep inside (more positive offset) without the inner sidewall contacting the UCA's...

Are you sure that RPG's have 1.5" uniballs? From the description on their website of their billet UCA's, it's 1"...

SVC billets are 1.5" uniballs. But some have recommended the Icon UCA's because of their fully sealed and greaseable Delta upper ball joints, which is what I'm leaning towards, if not the SVC's. The GS 460's I run with both use Icon UCA's.

I don't know where you're getting info stating you need -13mm offset to clear aftermarket UCA's, but SVC's UCA description specifies minimum 0 offset:

As I mentioned in a previous post, I'm running 20x9+1mm and 35x12.5 and have no rubbing whatsover under full articulation and full lock in either direction, with plenty of clearance for an aftermarket UCA; it will definitely clear the Icons, I'm confident it will clear SVCs as I doubt 1 itty bitty millimeter will make any real-world difference with all the sidewall flexing that may occur that I'm sure SVC has allowed some generous clearance gap when determining a mimimum offset.
I'm going totally off heresay, Raptor friends and forums Augster, and I thank you for this info! That -13 was my erroneous calculation using the online calculator. I like your real-world experience way better! Same for the SVC uca info. I heard RPG also had a 1.5" uniball option from a friend that's 'Mr RPG Everything' but couldn't find it myself. Coincidently I bought my Screw with the rear RPG bumpstop kit, and it seems to work well. I'm brand agnostic for what that's worth. When my oem uca's go I will upgrade. Ran many forms of 'awesome 1" upper ball joints' in my prev Duramax truck and went through several sets :( !

https://www.1010tires.com/Tools/Wheel-Offset-Calculator

I've made notes of your specs, and will shop accordingly :cool:!!
 
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FishFreak

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Now you're talking! Let's C-Notch a Raptor!
Hahaha!!
Chef's kiss. Bellisimo.
Lol you guys are killin' me! Pic is a riot :D!

I'm not sellin' my oem 17" SVC beadlocks, aamof, just for you guys, on my next set of new tires, I'll go back to my 17's and see what I like best. Since my Duramax got totalled last month I've got a set of beautiful 95% new 35/12.50R20 Toyo MT's sittin' in my garage. Yea grandma in a Corolla full of kids with a death wish ran a red light and turned in front of me, it was pure luck everyone survived.

signal-2024-01-23-084250_002.jpeg signal-2024-01-23-084250_005.jpeg signal-2024-01-23-084250_006.jpeg

I'll try these 20's out and report back. If they're miserable, I'll just sell 'em next month on FB Marketplace to a guy with a C-Notched F150 ;):D!!
 
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