Bigger contact patch? or more pressure per square inch?

[DigJeepsBrah]

I'm going to make a rather redundant comment and say that I have a lot of experience with R/C crawlers and the debate is alive and well in that community as well.

No one seems to have the holy grail of answers to this question.

I know that the driving surface has a lot to do with it, so lets just consider the typical dry and rocky terrain of most the trails in Colorado.

I know I'm going to be in the market for 33"s soon, and I'm just trying to get a grasp on why I should limit myself to a 33x12.50 when I know I can still get 33x10.50's...

Seems to me like it's a no brainer, other than it might not look as cool at the mall.

Narrower tire means (to me, correct me if I'm wrong); higher ride height after air down, smaller contact patch so there is more pressure per square inch on that contact patch, easier to stick a line and miss rocks/obstacles.

What are the downsides?

 

[time2getdirty]

You are over thinking it.

 

[YELLAHEEP]

You're talking about 2" of tread surface (1" either side of the center line of the contact patch if you will....)

Not really a huge difference where the contact patch and aired down ride height is concerned.

Wheel width is more critical if you ask me. If you have a 10" wide wheel..... The 10.5" tire will not grab side traction as well as the 12.5" tire. If that makes sense.

Had a buddy who ran 33x9.50's on an 8" wheel. He had the WORST traction out in Moab because the tall sidewall would walk under the wheel when turning ot trying to climb using the side lugs.

Wider is better if you ask me for trails and rocks. Narrow for MPG, mud and snow.

 

[YELLAHEEP]

You're talking about 2" of tread surface (1" either side of the center line of the contact patch if you will....)

Not really a huge difference where the contact patch and aired down ride height is concerned.

Wheel width is more critical if you ask me. If you have a 10" wide wheel..... The 10.5" tire will not grab side traction as well as the 12.5" tire. If that makes sense.

Had a buddy who ran 33x9.50's on an 8" wheel. He had the WORST traction out in Moab because the tall sidewall would walk under the wheel when turning ot trying to climb using the side lugs.

Wider is better if you ask me for trails and rocks. Narrow for MPG, mud and snow.

 

[in4aride]

way over thinking it.
too many other variables.
buy what you want and learn to drive accordingly. (goes for just about any modifications to the jeep)

 

[time2getdirty]

I had and loved 33x10.5s. Almost posotive I would have loved 33x12.5s too.

 

[WTF_LOL]

I think the big comment here is "for Colorado". You can argue details for other areas, but for here there is just something about being able to air a 12.5" tire way down and just float down long bumpy access roads/trail heads which otherwise just woulda rattled your nugin. (how the **** do you spell "nugin"?)....anyway, I agree also with the other post that mentioned sidewall flex. For me a 8" wheel with a 12.5" wide, quality tire just wraps and grabs ledges so much better than I could ever imaging a 10.5" on a 8"ish wheel doing.

 

[WTF_LOL]

Oh and in regards to your question about contact area/PSI...I tent to think more in the terms of float, or dig, or grab rather then pressure per inch. Generally wider tires "float" and "grab" better.

That's why I think you see narrow tires on mudders or sometimes snow bashers. Narrow tires with wide void tread tend to dig, getting you down through the slop to some more solid stuff. Wider tires with smaller voids tend to float which prevents you from getting down deep through slop, which inversely keeps you on top of loose dry rock scrambles. Wider tires also grab and absorb shock better (with wheel widths considered).

IMO:
Colorado, Dry Rock Crawing, etc = Grab, Absorb, Float > Dig, cut, void = South, muddier sloped areas, etc

 

[in4aride]

sidewall flex doesn't benefit anything other than smoother ride.

tread face flex is what provides 'bite' or 'grip'

 

[WTF_LOL]

sidewall flex doesn't benefit anything other than smoother ride.

tread face flex is what provides 'bite' or 'grip'

Thats a god point, I totally agree with you. I prolly should of said something more like a "Softer compound tire" or something to the effect.

 

[DigJeepsBrah]

Wow, see. This is why I ask. I had totally sold myself on the idea of 33x10.50's but the direction of this thread is steering me back to 12.50's...

In speaking of air pressure.. How far down is to far down without beadlocks?

 

[in4aride]

depends on rim width, rim size. Tire width and tire..... Lol

 

[Boostwerks.com]

Wow, see. This is why I ask. I had totally sold myself on the idea of 33x10.50's but the direction of this thread is steering me back to 12.50's...

In speaking of air pressure.. How far down is to far down without beadlocks?

It depends entirely on the tire and wheel combo.

For example, I can air my 285/75/16 E rated maxxis's (33 x 11.5) down to practically nothing due to the ridiculously thick sidewalls and the fact that I'm running a narrow 7" wide rim.

However a typical LT tire on a more common 15x8" rim is much different.

Experimentation is really the best way to go in that aspect.

 

[DigJeepsBrah]

Interesting. I'm on stock 15x7"s with 32x11.50 yokohama geolanders. I typically air down to about 15 pounds. Can I actually go lower than that safely?

 

[Gunter]

buy what you like that fits your needs and wheeling style. as said, too many variables from engine condition to the surface and weather and auto vs stick etc and so on.

 

[time2getdirty]

I had my dad aired down to 6psi last night on moabs and 305s.

 

[in4aride]

and don't be caught in common mindset that load range changes sidewall. 90% of the time it does not. Load range relates to tread plies.

for those that don't believe me, look at your sidewalls. It will tell you 3-4 plies for sidewall on almost every P or LT tire out there.

and airing down depends on trail, conditions, how much sidewall abuse tires will see, tire and rim width etc etc

 

[DigJeepsBrah]

Any of you guys ever re-set a bead with lighter fluid or ether?

That looks pretty intense.

 

[jdxj]

Any of you guys ever re-set a bead with lighter fluid or ether?

That looks pretty intense.

Just put a ratchet strap around it a tighten it up them youll be able to wiggle it around and get the air to stay in!

Ive seen guys do the ether thing but seems dangerous to me:flame::flame::flame::flame:

 

[in4aride]

Any of you guys ever re-set a bead with lighter fluid or ether?

That looks pretty intense.

Yes butkeep your face back. Ratchet strap is best trick for sure. Even if you do fluid the tire. Do not use a lighter, use a match, so you can toss it. I leave core in so it will burn off the air and suffocate the flame. Then pull core and let out the smoke, refill with air.