Dual Rear Wheels and Mild Off-roading - Is it Really That Bad?

[CoyoteThistle]

So I know all the standard reasons why dual rear wheels are frowned upon off road. Main fear seems to be rocks stuck between tires damaging sidewalls. Also more tire pushing through deep sand or snow instead of single rear tire following the tracks of the fronts. That all makes sense, but what does it mean in the real world? I've seen plenty of dually ranch vehicles on a wide range of dirt roads out west here - where there are rocks and snow. In the off road camper world, dual rear wheels seem to be unacceptable however. I know singles look cooler and more off-roady and give more tire size choices, but is there really more to it than that?

For context, I'm looking at platforms for a 4X4 or AWD camper build that will wind up in the 10k lbs total weight neighborhood. I have absolutely no illusions that something that big will be a real off road vehicle but it would see plenty of dirt roads, snow, and likely some sand here and there. But, 95% of driving will be on highways where the extra stability of DRW sounds like an advantage. And the extra cost of converting to super singles is not appealing. My preferred platform at this moment is only available as DRW, but that is really the only downside of that truck. Trying to get you all to talk me into it being okay (or a horrible idea ).

Thoughts?

 

[NevadaLover]

Personally I think that rocks would be only real threat around here, I'd never take a dually into the dunes here but a little sand wouldn't turn me around, like you said the stability would override the detriments if I had a heavy load, I say go for it.

 

[NatersXJ6]

I’ve worked decades in mining and heavy civil construction. Life overloaded on a site is far more detrimental than mild off-roading and most of those trucks are dually. I wouldn’t hesitate if I wanted that kind of load capacity. It is rare to be driving on loose rock of exactly the size to catch between tires.

 

[IdaSHO]

The single reason why we kept to a SRW setup is how utterly useless (and dangerous) a dually can be in slick winter/snow/ice travel.

 

[CoyoteThistle]

The single reason why we kept to a SRW setup is how utterly useless (and dangerous) a dually can be in slick winter/snow/ice travel.

Hadn't heard that before. Can you elaborate on the reasons for this?

For my build, there would be lots of weight on the back axle at all times. Also clever AWD, traction control, ABS, etc. Still an issue in that case you think? Being safe on slick roads is a priority for me.

 

[IdaSHO]

The reason is simple. You literally have twice the tire contact patch, so applied PSI from tire to surface is reduced by 50%.

Running loaded all the time will help. As will tire selection. If you intend to run on slick surfaces, the last thing you want is a tire with large tread blocks and/or hard compound rubber. So avoid mud terrain tires. Stick to a winter rated AT or highway tire.

 

[1000arms]

For the driving you have mentioned, I think you will be happy with DRW.

Many US Forest Service trucks are DRW. Many logging trucks are DRW.

DRW trucks can be a cost-effective way to get the load capacity one wants/needs.

Tire tread and compound choices can greatly impact traction.

Keeping the DRW's loaded can help with traction in snow and ice. This works with SRW trucks too. Even Home Depot and Lowes sell "tube sand" for winter weight in pickup trucks. Running the right tires is also part of good winter traction.

Sand beaches vary, but there are many DRW trucks with truck campers driven on beaches. Being able to "air-down" the tires is often helpful/needed. Running stock DRW tires helps with airing-down tires without rubbing. Keep in mind that airing-down some tires can dangerously damage them (for example, many commercial tires with 19.5" rims fall in to this. Look up "tire zipper effect".). I suspect that most of the DRW vehicles that you will be considering come standard with 16" rims or 17" rims, which should air-down well (beware tire rubbing).

 

[1000arms]

Part of your vehicle-platform thoughts should probably include recovery points. A body-on-frame usually allows for mounting tow-hooks (and/or other connection points) to facilitate "vehicle recovery", but many unibody vehicle don't have the ability to handle stresses concentrated in one area. The ability to easily be tugged free from a minor "stuck", by another vehicle, can be quite nice. Be able to be safely winched/pulled form a "very stuck" is extra-nice.

 

[CoyoteThistle]

Good input all, I really appreciate it. Nice to hear real world experience/examples of DRW trucks putting in the miles on dirt roads without major issues. That gives me considerable peace of mind.

Sounds like upgrading tires to something with the mountain snowflake rating would be a priority. Add it to the budget I guess!

 

[deserteagle56]

My old Dodge/Cummins dually has thousands of off-highway miles on it, most of the time loaded as seen in the pic below. I had the camper on a SRW truck before and there's just no comparison in how much more stable the dually is, especially when on an off-camber side hill. Never once have had a rock stuck between the duals. Biggest problem I've found driving dirt roads is those that have severe washboards...the vibration will shake apart a camper, crack ABS drain lines..............

As far as problems caused by duals on snow or ice...I wouldn't know. When there's snow and ice on the roads I stay the hell home and feed the fire!

 

[IdaSHO]

Yah, some of us weirdos go everywhere, near regardless of season or weather.
That's why you go with a 4-season setup, right?

 

[1000arms]

... Sounds like upgrading tires to something with the mountain snowflake rating would be a priority. Add it to the budget I guess!

Please be aware that the Three-Peak Mountain Snowflake Symbol only indicates a minimum performance standard.

"In 1999, The U.S. Tire Manufacturers Association (USTMA) and the Rubber Association of Canada (RAC) agreed on a performance-based standard to identify passenger and light truck tires that attain a traction index equal to, or greater than 110 (compared to a reference tire which is rated 100) during the specified American Society for Testing and Materials traction tests on packed snow. The standard is intended to help ensure drivers can easily identify tires that provide a higher level of snow traction, and tires meeting that standard are branded with the three-peak mountain snowflake (3PMSF) symbol.

Some important information to remember about 3PMSF branding.

Testing measures a tire's acceleration traction on medium-packed snow only. Braking and turning on snow, along with ice traction are not components of the test.
Tires branded with the 3PMSF symbol are expected to provide improved snow traction beyond a standard M+S branded all-season tire, however 3PMSF-branded all-season and all-terrain tires cannot match the traction of dedicated winter / snow tires in all winter weather conditions and should not be considered a replacement for where and when a dedicated winter tire is needed." From: https://www.tirerack.com/upgrade-garage/what-is-the-threepeak-mountain-snowflake-symbol

Depending on where you will be driving, having tires with the Three-Peak Mountain Snowflake Symbol will likely be useful, but I would suggest choosing Three-Peak Mountain Snowflake Symbol tires that greatly exceed the "traction index equal to, or greater than 110" mentioned in the quote.

Depending on where one lives and drives, one might want to consider dedicated winter tires.

Having tire chains, and knowing how to use them, can be quite helpful in snow/ice and mud. ... Check out: https://bangshift.com/bangshiftxl/l...rator-save-another-machine-frozen-lake-maine/

 

[BikePilot]

A well driven drw will go just about anywhere it'll fit. Check out the Randy's guys.
Fyi as far as I know there are no mainstream US market drw trucks that are AWD or have any sort of fancy traction control. The Ram 3500, F350, GM 3500s etc are still decidedly old school with traditional selectable transfer cases and no center diff.

In terms of weight are you saying the camper itself will be 10k lbs or the whole rig? Unless it's a camper trailer a 10k lbs camper is going to need a huge commercial truck. A 10k total weight truck + camper will be difficult. A Ram 3500 drw diesel is over 9k lbs ready to drive and that's before you put a camper on it. Maybe if you go for a regular cab gasser it would be possible. But at only 10k lbs there's no point in a drw unless you are also towing heavy.

 

[CoyoteThistle]

Please be aware that the Three-Peak Mountain Snowflake Symbol only indicates a minimum performance standard.

"In 1999, The U.S. Tire Manufacturers Association (USTMA) and the Rubber Association of Canada (RAC) agreed on a performance-based standard to identify passenger and light truck tires that attain a traction index equal to, or greater than 110 (compared to a reference tire which is rated 100) during the specified American Society for Testing and Materials traction tests on packed snow. The standard is intended to help ensure drivers can easily identify tires that provide a higher level of snow traction, and tires meeting that standard are branded with the three-peak mountain snowflake (3PMSF) symbol.

Some important information to remember about 3PMSF branding.

Testing measures a tire's acceleration traction on medium-packed snow only. Braking and turning on snow, along with ice traction are not components of the test.
Tires branded with the 3PMSF symbol are expected to provide improved snow traction beyond a standard M+S branded all-season tire, however 3PMSF-branded all-season and all-terrain tires cannot match the traction of dedicated winter / snow tires in all winter weather conditions and should not be considered a replacement for where and when a dedicated winter tire is needed." From: https://www.tirerack.com/upgrade-garage/what-is-the-threepeak-mountain-snowflake-symbol

Depending on where you will be driving, having tires with the Three-Peak Mountain Snowflake Symbol will likely be useful, but I would suggest choosing Three-Peak Mountain Snowflake Symbol tires that greatly exceed the "traction index equal to, or greater than 110" mentioned in the quote.

Depending on where one lives and drives, one might want to consider dedicated winter tires.

Having tire chains, and knowing how to use them, can be quite helpful in snow/ice and mud. ... Check out: https://bangshift.com/bangshiftxl/l...rator-save-another-machine-frozen-lake-maine/

Thanks, good stuff to know. Out west my experience and those of friends is that tires with that symbol perform amazingly well. We mostly deal with snow and rarely really icy conditions. If the roads are really icy the skiing probably isn't great so no need to go anywhere! And I always carry chains in winter.

 

[CoyoteThistle]

A well driven drw will go just about anywhere it'll fit. Check out the Randy's guys.
Fyi as far as I know there are no mainstream US market drw trucks that are AWD or have any sort of fancy traction control. The Ram 3500, F350, GM 3500s etc are still decidedly old school with traditional selectable transfer cases and no center diff.

In terms of weight are you saying the camper itself will be 10k lbs or the whole rig? Unless it's a camper trailer a 10k lbs camper is going to need a huge commercial truck. A 10k total weight truck + camper will be difficult. A Ram 3500 drw diesel is over 9k lbs ready to drive and that's before you put a camper on it. Maybe if you go for a regular cab gasser it would be possible. But at only 10k lbs there's no point in a drw unless you are also towing heavy.

MB Sprinter AWD cab chassis is only available with DRW. 10k is my current rough estimate of truck, camper, gear, etc.