Off Road Class C Motorhome and Extended Tray

RobertRyan wrote:
Still you can buy here vehicles with much better ground clearance,

I'll bet you can ... here in the U.S. too.

.... and how do the builders of these vehicles get the differentials, transmissions, engine pans, gas tanks, suspension components, etc., up high off the ground? They do it merely with taller tires and/or by also lifting the frame higher above the axles. Add a big tall (non-crank-up) RV living area box on top of the frame and you get the anti-offroad affect of raising the center of gravity even higher.

The real offroad engineering in the HumVee - being described here by the folks who know it - stands head and shoulders above the brute force methods of merely combining more and more steel with ever-larger tires. All these designs get you is high ground clearance at the expense of a higher than necessary center of gravity and (due to the narrowness of the tire track) a poor height-to-width lateral-stability geometry.

In an earlier post RobertRyan graciously provided the wheelbase length and track width for that photo of a (at first glance) mighty-looking expedition RV with a porch that he started this thread with. Here's the dimensions he provided:

RobertRyan wrote:
PNichols on the SLR Motorhome with Patio it is

Quote:

Wheelbase is 11.138 ft. Distance between the tires about 5.5 ft. This is on the non modified truck.

Note how tall (looking at the photo of it) and narrow (from the distance between the tires dimension, above) that very expensive expedtion RV is!

Finally ... to factually make my original point on comparative RV offroad lateral stability ....here's the wheelbase and (most importantly) track width of our modest little 24 foot Itasca built on Ford's ton-and-a-half E450 truck chassis:

E450 wheelbase = 158 inches (13 feet, 2 inches)

E450 front track width = 75 inches (6 feet, 3 inches)

E450 rear track width = 95 inches (7 feet, 11 inches)

Granted that those expedition vehicles have tremendous raw mechanical component ground clearance for mud/snow, road ruts, and rocks due to tall tires ... but I stand by my position that many of them are too narrow versus their heights for the best safety on offroad surfaces that may also tip the vehicle into aggressive angles. If they were built using drive system designs like that of the HumVee ... and if they had crank-up coach areas for lowest possible center of gravity ... then one would REALLY be getting something for the six-figure prices of them.

I will grant that their track narrowness does make travel with them in European cities easier, but why would wide-open Australia require unduly narrow RVs offroad in the outback? Wide and low is the name of the game.:C