SMB, Alaskan, or Tiger; Can Tiger Withstand Rough Roading

[TomH]

I have been considering three possibilities for a vehicle that could serve as an off pavement and rough road vehicle. It also would be capable of towing a 4000 lb. travel trailer for the times we want to set up camp for an extended period and stay put in a campground with amenities. I certainly would buy an EarthRoamer XV-LTS if I could afford it, but $300k is beyond my budget, so it's between these three.

The first is a Sportsmobile Ford E350 Extended Body 4x4 conversion.

http://www.sportsmobile.com/index.html

The second is to take an F350 crew cab long bed/utility bed pickup and put an Alaskan Camper pop up unit on back. We would take out the rear seats and put in a very small fridge and a porta potti for use while the truck is in motion.

http://www.alaskancamper.org/Desktop.html

The third option is a Provan Bengal Tiger on an F350 long bed.

http://www.tigermotorhomes.com/home.htm

At this point in time, we prefer the layout of the Tiger and its larger size. Other than the cost, I have one overwhelming concern.

As Stephen Stewart describes here

http://www.xor.org.uk/silkroute/equipment/choosevan.htm

off pavement, and especially off road vehicles suffer great torsional stresses. Vehicles built on pickups and trucks are more likely to experience flex than the Ford van as the van frame is very strong, while pickup and trucks have a frame designed to allow the cab and payload sections to flex independently of each other. This is illustrated in these pics of Jay Shapiro's F650 build:

http://www.expeditionportal.com/foru...&postcount=193

2nd through 7th pics in this post:

http://www.expeditionportal.com/foru...&postcount=182

2nd pic in this post (finished build-note caption re. ripped bellows):

http://www.expeditionportal.com/foru...&postcount=462

Most pickup trucks have a separate cab and bed to allow flex between the two. Some older unibody exceptions, based on car frames, were Chevy El Camino, Cadillac Mirage, Ford Ranchero, and VW Rabbit pickup. Today's Sport Utility pickups like the Honda Ridgeline, Cadillac Escalade, Chevy Avalanche, and the crossover SUP Subaru Baja are unibody. The only true pickup that I've come across that was unibody is the '61-'63 F100. All of these were/are relatively short vehicles. Most big trucks also have separate cab and body, though U-Haul types and some other delivery trucks are fused. I think of all the Unimog type Overlanders that have completely separated cabs and cabins.

Stephen Stewart states that when using a truck chassis as a camper platform, if one wants to have a passageway between the cab and chassis, one of two solutions has to be employed to solve the problem of torsional stress. The first, which involves fusing the cab and chassis, is to greatly strengthen the frame so that it simply doesn't flex while firmly affixing the cabin to the main frame in a minimum of three non-linear points. The second is to join the cab and cabin together so that they can move independently. This is accomplished by putting the cabin on a subframe (normally two rails) and joining the cab and cabin with bellows.

Jay's EcoRoamer uses subframe and bellows. So Does EarthRoamer on the XV-LT and XV-LTS, and Global Expedition Vehicles on the UXV-550 S-84.

http://www.earthroamer.com/index.html

http://globalxvehicles.com/uxv-550/

(Update 10-9-11: Provan is soon to release the Siberian Tiger which will use subframe and bellows. The Unicat site shows the subframe and bellows method for an XV on a F-550, in 4x4 and 6x6 versions built on all 3 cab sizes. Apparently, this is concept only at this point, as I can find no evidence they have ever built one. The copyright date at the bottom of the page is 2006. On another page they have a copyright 2007 design they released built on a Dodge Ram 5500 which they apparently never built:

http://unicatamericas.com/en/index2-Amerigo.html

http://www.unicatamericas.com/vehicles_dodge_5500.html )

There are several pickup based 4x4 Class C vehicles that I have found which fuse the cab and cabin and attempt to strengthen the frame:

The Host Super-C Series:

http://www.hostcampers.com/subs/moto...otorcoach.html

The Xplorer Xcursion Series:

http://www.xplorermotorhome.com/xcursion_ford28.html

The Provan Tiger CX and Bengal Tiger:

http://www.tigermotorhomes.com/home.htm

The Krystal Motorhomes Models 30 and 33:

http://www.krystal.cc/1.html#/exterior

The Suncamper Sherwood:

http://www.suncamper.com.au/sherwood.html

The AC Landcruiser 80:

http://www.acmotorhomes.co.za/Landcr...0%20Series.htm

Three discontinued 4x4 pickup based class C motorhomes (all with fused cab/cabin) that are no longer produced include:

Toyota Chinooks:

http://www.expeditionportal.com/foru...ad.php?t=40847

The Serro Scotty Pioneer 4x4 and 6x6:

http://forum.ih8mud.com/vehicles-tra...motorhome.html

The Revcon Trailblazer 4x4 and 6x6:

http://www.fourdoorbronco.com/board/...1&d=1258988304

A number of these same manufacturers also produce(ed) motorhomes based on vehicles other than 4x4 pickups. Some interesting German campers, built permanently on pickups, yet having no pass through can be found here: http://extremfahrzeuge.com/Geocar_CONDOR.187.0.html )

I have been researching the Tiger as much as I can. On the Yahoo Tiger users forum, I find very little evidence that Tiger owners take their vehicles off pavement very often, almost no record of Tigers being taken onto rough unpaved roads, and absolutely no record of going completely off road. I also find a disturbing trend of the cabin developing cracks just behind the place where the cab and cabin are fused. The owners reporting this phenomenon have no idea what the origin might be, however I fear that Stephen Stewart's observations about torsional stresses are likely the source of the problem. Here is where the problem is discussed amongst Tiger owners on the Yahoo forum.

http://autos.groups.yahoo.com/group/...e&var=1&tidx=1

I welcome comments and observations about these cracks in the Tigers. Do my concerns about torsional stresses seem reasonably founded? I also worry about the Tiger's suitability in withstanding stresses of harmonic resonant vibrations on washboard roads. I love the Tiger layout, however a little voice is whispering to me that the 4x4 on Tigers, Revcons, Host Super Cs, and Xplorer Xcursions is best utilized on icy paved roads, and not on unpaved rough roads. These vehicles also do not have the suspension upgrades that EarthRoamers, Global Expedition Vehicles, and Sportsmobiles have. For any Tiger owners (or owners of those other three) who have done serious off pavement/rough road overlanding, I would especially appreciate your observations. Thanks in advance.

[wild1]

I looked at all three of the vehicles that you are interested in when I was considering what to buy. They all have their strengths but I think that the pickup, utility bed and an Alaskan or similar popup camper is the most versatile
combination that you have identified. One of the nice things about this setup is that you can shop around for components on the used market and cut your outlay to a fraction of the new cost of the truck and utility box. I have put over 50,000 miles and hundreds of nights on my setup with complete satisfaction. While very little of this would qualify as serious offroading a great deal of those miles were on dirt roads and two tracks throughout the western US and in Baja. I often tow my LJ and TW Yamaha enduro so a 4000 pound trailer should be no problem. Good luck.

[N8URE2]

while I have no experience to offer I am very interested in this thread as I will one day be in this same boat.

one question, what are the differences between the CX and the Bengal Tigers? A quick look at the Tiger site I couldn't find anything other than the CX, I could just be missing something tho.

Thanks, good luck, I will be following this one....

[mhiscox]

What are the differences between the CX and the Bengal Tigers?

Interior height. The plain CX is from 5’11” to 6'1" inside, with an overall height of about 10 feet. The Bengal Tiger is six inches taller outside, which means it can have a consistent interior height of 6'4".

[goin camping]

I've been down this road and don't be surprised if your research leads you to some other set up.

We went with an 25ft Airstream and a truck. There is a pop up camper in the near future. That way we have travel in comfort and have wilderness ability.

Think about making a pick up truck the center of your system. Trucks are cheap and versatile. They can tow, haul and carry. If your truck is the right size you can tow the palace and your camper. Then you can drop your trailer in an RV park and go out into the wilds for as long as you want and have a base with all the comforts to come back too.

I do have grave concerns that the Tigermobile can withstand serious off road or even lots of exposure to rough dirt roads. Trucks flex and I don't see where that was built into the Tigermobile. Hopefully there are Tigermobile owners here that can address that.

Good luck in your search.

[TomH]

....what are the differences between the CX and the Bengal Tigers? A quick look at the Tiger site I couldn't find anything other than the CX, I could just be missing something tho.....

mhiscox is correct. Scroll to the bottom of this page and see the footnote for the double asterisk.

http://www.tigermotorhomes.com/pricing.htm

[TomH]

I've been down this road and don't be surprised if your research leads you to some other set up.

We went with an 25ft Airstream and a truck. There is a pop up camper in the near future. That way we have travel in comfort and have wilderness ability.

Think about making a pick up truck the center of your system. Trucks are cheap and versatile. They can tow, haul and carry. If your truck is the right size you can tow the palace and your camper. Then you can drop your trailer in an RV park and go out into the wilds for as long as you want and have a base with all the comforts to come back too.

I do have grave concerns that the Tigermobile can withstand serious off road or even lots of exposure to rough dirt roads. Trucks flex and I don't see where that was built into the Tigermobile. Hopefully there are Tigermobile owners here that can address that.

Good luck in your search.

From the standpoint of cost and practicality, I am coming to the same conclusions as you. The most important thing for me, however, is for my wife to be comfortable and satisfied with the entire rig. Otherwise she will not want to travel. We have been in a Tiger and have toured the Sportsmobile factory-going into many Sportsmobiles. The Tiger has more space and a better layout, while it is the Sportsmobile that can really go offroad and suffer no damage. She is not thrilled with the necessity to get out of the cab and walk around to the rear of the vehicle. Both the Tiger and the Sportsmobile (I wish the Tigermobile you wrote of really did exist!!) allow you to get out of the front seats and go straight to the living area. The one drawback of a pickup with an Alaskan Camper pop-up on back is that you have to walk around to the back, lift the top, then get in. In a Sportsmobile or a Tiger, you can walk right through. The perfect vehicle for us would be an EarthRoamer XV-LTS, but we could never afford $300k. Again, though, I think you are correct on every point you have made. I have put together a little Power Point showing pics of the torsional twisting and of pickups with the Alaskan Pop-Top also towing an Airstream. I will see how she responds to it.

Please keep the feedback coming guys. I need and welcome advice.

[squeezer]

I can give a bit of insight on the Tiger. (I own a 1995 CX, 6.5Turbo Diesel, NV4500 trans, 4x4). From the standpoint of torsional stiffness, I would not be afraid to take the Tiger anywhere it will fit. The camper cross members are welded to the frame and the entire setup is pretty solid. Where a Tiger will get into trouble off road is the low hanging holding tank plumbing...

[TomH]

I can give a bit of insight on the Tiger. (I own a 1995 CX, 6.5Turbo Diesel, NV4500 trans, 4x4). From the standpoint of torsional stiffness, I would not be afraid to take the Tiger anywhere it will fit. The camper cross members are welded to the frame and the entire setup is pretty solid. Where a Tiger will get into trouble off road is the low hanging holding tank plumbing...

This is good to hear. Some follow up questions, if you don't mind. In that your Tiger is 16 years old, Provan is under different ownership, etc., what truck is your Tiger built on? (Is yours a truck or a converted Astro van?) Is the cabin fiberglass, aluminum, something else? How much driving do you do on uneven roads that cause torsion? How much on washboard roads, and how has the cabinetry, etc. taken the washboard vibration, other stresses? Is your rig reg., extended, crew cab and what's overall length? (The longer the frame, the easier for torsion to torque some twist into the frame.) I'd appreciate all the details you can give about kinds of roads you've been on, how many miles, etc. Thanks for your feedback.

[UHAULER]

Tom, have you seen this one, I didn't see it mentioned in your thread( or I missed it)

http://www.expeditionportal.com/foru...ighlight=tiger