34x10.5-R17 Tires with 4Runner "Snowflake" wheels

Hey all,

I got some Toyo AT3 34x10.5-R17 tires put on the Taco and I went with a 17x8.5 0 Offset wheel. I am now starting to question my wheel choice since the tire isn't wide like a 285. I am thinking I should have gone with the 4Runner Snowflake wheels (+15mm offset ) to minimize scrub radius as much as possible.

I got an alignment done, but not at an off-road specific shop. He knew exactly what I was talking about when I asked for ~3.5 or so of caster and there were a couple other off-road vehicles in the shop, so I had faith. Numbers look good post alignment.

I am wondering if going with a +15mm offset will increase tire clearance by the same amount or if it will be a somewhat negligible difference in scrub radius? (15mm is about 0.59 inches)

Currently, does my cab mount clearance look too tight? I definitely rub some plastic, but that can be trimmed. Trying to avoid a CMC.

For those interested, the tire measures just a hair over 33” mounted @ 35PSI. It measures about 32.5” on the truck @ 31PSI. More like a 33” than a 34” for sure. This tire is just a tad wider than 265/75r16 (+0.08" wider according to tire calculator).

Driver:
Passenger:

 

I’d say just go ahead and just get the CMC if you can. It’s pretty hard clearing larger (33”+) without doing one. I mean, all our trucks vary slightly, so I’m not saying that it is impossible to get away without doing one. But it will open up a lot of options and it is a pretty straightforward modification.

the other thing is that your selected tire size and width are somewhat less common here. There are loads of people running 255/80/17, 285/70/17, and even 285/75/17 ( also a skinny 34”) but your tires are ever so slightly more narrow than your average 33 or 34. That should work in your favor.

I see you already have the Dobson upper control arms. If you did not already have those, I might suggest the SPC upper control arms to gain some clearance flexibility and adjustment.

I just feel like if you already like those tires and wheels the easiest step and probably eventual step that you will more than likely make somewhere down the line would be just to do a cab mount chop.

I think the guys running 255/80/17 have the best chance of clearing a 33 without needing to do a CMC.

by way of comparison, here’s a picture of my 285/75/17’s on a 17” x 8.5” -10mm SCS F5 and a CMC.

 

What is your suspension setup?

 

Parts are listed in my signature. The front 650 lbs 6120's on not on the tallest clip.

 

Thank you for the reply! I guess I was trying to avoid the CMC if I can. My main question is if having a +15mm offset instead of 0mm would reduce the scrub radius enough to clear them without a CMC. I feel like I am pretty close on the passenger side to clearing it even with 0 offset wheels. After much research, I haven't been able to find out how much cab mount clearance is "enough" to not rub in all circumstances. I watched a video where one person claimed that "2 fingers" is enough....very scientific. =)

I of course like the wheels I chose, but in all honesty I would rather do the Snowflake wheels and avoid a CMC.....if having that more positive offset actually cures the rubbing.

 

Correct me if I'm wrong, but wouldn't you want to go with a negative offset wheel if you are trying to insure no cab mount interference? I thought that a positive offset wheel moved the centerline of the tire in towards the body and negative offset wheels moved the tire centerline out (poke).

 

This is a common misconception. A more negative offset helps you run wider tires so you can clear the upper control arm, but actually decreases body mount clearance because it increases scrub radius. Ideally, you want to run just enough offset so your tires clear the UCA and that's it. The more positive the offset, the less scrub radius, the more body mount clearance you get.

People run more negative offset wheels for the looks as well, but from a technical standpoint that actually reduces clearance.

Unfortunately, there aren't a ton of wheel choices in 17inch size with an ideal positive offset if you are trying to stay around 4.75 to 5 inch backspacing. It seems the OEM wheels are actually some of the better choices.

Tinkerer's Adventure has a good video explaining this in more detail:

 

After doing a bit more research, I am wondering if I can get away with higher than +15mm offset.

TRD Sport wheels are 17x7.5 +30mm offset (5.5" backspace). People clear 265/70/R17 no problem with these on stock suspension. 34x10.5-R17 tires are basically the same width (.25" wider based on real world measurements)

TRD OR Wheels are 16x7 +25mm offset (5" backspace).

My UCAs claim to also have a little more room for tires than stock UCAs.

It stands to reason I could go with a 17x8 +20mm offset wheel (~5.28" backspace) and clear the Dobinsons UCAs while minimizing scrub radius as much as possible.

Thoughts?

 

Could you show a direct front and rear shot of the truck please? I’m considering these on a 8inch rim, and want to see how “skinny” these look.

 

I wonder why he went with a 8.5” rim instead of the 8” and if the 8” would have caused less of a problem.
That tire width Is essentially stock.

Chiming in because I’m more interested in this tire height/width than a 285 and seems like there’s a very limited choice for 17” and less for a 16” (both rim & tire options).

 

I can grab some pictures later today. For reference though, these are basically stock 265 width. So it's defintely on the "skinny" side, but thats not a bad thing. If you haven't yet, watch Tinkerer's video about his tire width experiment and you will see skinny does not mean less performance. I also drive in a lot of heavier snow and a skinnier tire is better for that.

An 8.5 inch VS. 8 inch wheel makes no difference in clearance for cab mount or front bumper. It would only affect the backspacing (combo of width and offset), which affects clearance for the steering components.

I originally went with an 8.5" 0 offset wheel and had some minor rubbing of the cab mount. I do not have a CMC. I ended up switching to a 8" +20 offset wheel to reduce scrub radius and this now fully clears the cab mount at full flex.

I went with these: https://www.bbwheelsonline.com/pro-...7x8-6x139.7-matte-black-20mm-pa200mx17806820/

Another option: https://www.bbwheelsonline.com/pro-...7x8-6x139.7-matte-black-20mm-pa203mx17806820/

If you already have a CMC, you could use the ones I originally bought (they are for sale!): https://www.americastire.com/buy-wheels/raceline-952b-aero-hd/p/104386

You might be able to get away with these OEM wheels as well. These are the ones I was talking about in my original post. 5mm more negative offset than what I currently run, but would probably still clear the cab mount without a CMC: https://oemtakeoff.com/products/set...-toyota-4runner-tacoma-17-silver-wheels-75153

OR

https://oemtakeoff.com/products/set...-fj-cruiser-black-machined-oem-takeoff-wheels

 

That is one fugly cmc. I hope that sucker was cheap.

I'll be curious to see next spring how much the clearance changes from my 295/70 when going to a 285/70. It'll be nice to shave a little more weight off but increase the height.

 

Beware spindle gussets may not fit with those offsets. No point in a larger tire if you then can't wheel aggressively with them.

 

I have RC Fab gusseted spindles installed. They are beefy. Clearance is tight, but it does fit. I wold not recommend anymore than 5.25" backspacing with those gussets. I have 5.29" backspacing. Any stock wheel will work with those specific gussets except the TRD Sport wheels, which are 17x7.5 and +30 offset (5.44 backspace).

 

I'd love me sum 34" pizza cutters.

These are the only ones I know of.

 

The maxxis razor AT is available aswell. As I'm pretty sure the g018 in a 285/75r17 weighs 4.5 lbs less than the baja boss

 

Bajas are heavy and according to my trusted tire shop sometimes don't balance well. Why not go "mid-skinny pizza cutters" like the Toyo ATIII 34x10.5r17s? They are D load range. Lighter than the Bajas, and are also 3 peaks snow rated.

 

Both of those rims are far uglier than the stock offroad 16” ones.

No CMC yet, not that I’m looking to avoid it just not needed at the moment.


I’ve watched many of TA’s vids great info, also I’ve always run tall skinny for years, they work great.
Like he said it’s a balance of offset and backspacing which I’m a little overwhelmed by when considering new 17 rims. The half inch extra width can’t be helping things especially when it’s not needed.


Ideally I’d like 34x10.5x16, maybe 11” wide, unfortunately I don’t see many options for 255/85/16 and that’s a limited size for rims too.

Cooper stt maxx are heavy too, E rated.

 

Why are you overwhelmed by it? Backspacing is a combo of rim width and offset. It's a math formula.

(Wheel width + 1") / 2 and then add or subtract the offset depending if its negative or positive offset.

Example for an 8" wheel with +20mm offset: (8 + 1) / 2 = 4.5" Then add +20mm (.787"). We end up with 5.287" backspace.

So you can see how width and offset BOTH affect backspace. The most you can run on our trucks is about 5.5". The TRD sport wheel are 5.45". Anything beyond that simply will not physically fit.

Wheel width by itself has nothing to do with clearance for tires when talking about cab mount and front bumper. Offset is what matters for that. Backspace matters when talking about the wheel clearing the steering components, like your spindles. You can only run so much backspacing before your wheel starts physically hitting your components. The wider your tire, the less positive offset you can run because your tire will hit the upper part of your spindle, UCA, etc.

I hope that makes sense. Sorry, I had to edit this a few times to add some examples and clarify what I meant.

TL;DR: To clear 34" skinnies with no CMC you need a "close to stock" offset wheel that is in the width range to be below 5.5" backspace. Basically the most positive offset you are able to run while being under 5.5" backspace. This will minimize scrub radius as much as possible. For me, this was a 17x8 wheel with +20 offset and my 34x10.5r17 tires. I could not find another aftermarket wheel with more offset that would be in the width range to have a backspacing that would clear my gusseted spindles. I probably have less than .25" of clearance....but it fits!

This might help you visualize it more:

 

Both great ideas, just worried how much work would be involved in fitting. Currently I have no rubbing, don't have spacers, have my mudflaps, and want to keep it that way. I do however appreciate that they have 3 peak snow rating. That's a must for me.