Narrow vs. Wide Tires

ekj · **Joined:** Tue Nov 03, 2009 3:55 pm **Posts:** 100

I thought this was a good read:
http://www.expeditionswest.com/research/white_papers/tire_selection_rev1.html

dgeist · **Posted:** Fri Dec 11, 2009 12:15 pm

So, with the libby weighing in at just over 4000 or 4200 lbs (gas/CRD), it looks like the ideal width is the following:

4,000-5,000

Mixed Terrain:
9.0-10.0 (225-255)

Soft Surfaces:
10.0-11.0 (255-285)

I'm guessing the vast majority of the users here fall into the Mixed Terrain group (with the most common widths being 245 and 255, probably.)

Dan

JNJ-Z · **Posted:** Fri Dec 11, 2009 1:44 pm

nice info,thanks

tjkj2002 · **Posted:** Fri Dec 11, 2009 8:21 pm

Quote:

Off-highway effects of contact pressure:

Deformation- On a smooth surface (like concrete), a tire gains most of its traction by adhesion. On an irregular surface like granite and boulders, a tires contact patch will deform as a result of vertical pressure. The wider the tire, the less the rubber will deform to the surface irregularity given the same vertical pressure. The greater the deformation, the greater the tires resistance to shearing forces (spinning). This is the strongest argument to using a narrower tire.

Real world example: When climbing a ledge with a jagged surface, the narrower tire will wrap the protrusions with more contact due to the increased deformation depth. The wider tire will rest on the surface of the protrusions and will have a greater chance of spinning (shearing).

That statement is false,a wider tire will "wrap around" a rock better then a narrow tire and will less likely damage a wider tire as you have a greater chance of damaging the sidewall cords in a narrow tire.

If the above quote was true you would see all the pro crawling guys running 8" wide tires since most of there rigs are very light but most use 12.50's or wider with a 2500lbs rig.

JNJ-Z · **Posted:** Tue Dec 15, 2009 9:20 am

X2 good point!!!!

ekj · **Joined:** Tue Nov 03, 2009 3:55 pm **Posts:** 100

Thanks for pointing that out. It sounded dubious to me as well, but I don't have the experience to disprove it.

Tokyojoe · **Posted:** Tue Dec 15, 2009 10:27 pm

We're experienced at Charlie Brown Halloween rock crawling. He tosses his rocks here in the Rockies (how the mountains grew) and we crawl over them. Wide and thick sidewalls.

JL Rockies · **Posted:** Tue Dec 15, 2009 10:33 pm

I roll 235/85 R16 and my rig is a heavy beast.

candpliberty · **Posted:** Wed Dec 16, 2009 12:44 am

Thanks, EKJ! Very nice read. Ahhhh, why is there no technical manuals on the best seller list. Nothing like sitting by the fire,popping a beer and reading a service manual.

E2 · **Posted:** Thu Mar 04, 2010 4:34 am

But what is too ratio does the tire width becomes too small? for 32's I can get a 235/85r16 or 265/75r16 in the BFG A/T's about 31.7" the width is 1" difference.

candpliberty · **Posted:** Thu Mar 04, 2010 1:25 pm

tjkj2002 wrote:

If the above quote was true you would see all the pro crawling guys running 8" wide tires since most of there rigs are very light but most use 12.50's or wider with a 2500lbs rig.

The only thing is their buggies have beadlocks and run 6-10 psi. They probably could run flat and hardly notice!

In the desert I lean toward a wider tire because in one outing you could go from deep sand to hard pack to rock piles and back again.
I wonder what the articles criteria is to make a tire wide or narrow. In the real world does it matter because we can't be carrying around a 2nd set of tires depending on the situation. We pick a set that we feel is best for us and most of us live with that decision for quite a long time.

candpliberty · **Posted:** Thu Mar 04, 2010 1:55 pm

E2 wrote:

But what is too ratio does the tire width becomes too small? for 32's I can get a 235/85r16 or 265/75r16 in the BFG A/T's about 31.7" the width is 1" difference.

I don't think you can purchase a tire with the diameter you want that is too narrow.

Narrow vs. Wide Tires

Who is online