All matters MRAP JLTV (merged thread)

[Stan]

A short and insightful read. Survival Consultants Intl CEO David Woroner raises some food for thought at his website, Defense Tech and at Breach Bang Clear's Blog.

There's even a para or two on Tires vs. Track at the blog link.

Tires vs. Tread, how will they move? This would seem to be a no-brainer, but I have to add it in. ... They’ll bog down far less frequently, and they can turn and maneuver far more effectively in urban terrain than anything with wheels.

[Distiller]

CV90 ... about 8 psi ground pressure.
M1 Abrams ... about 15 psi.
Patria AMV (the best 8x8 in my eyes) ... about 35psi. More than a heavy truck.

8x8 should be outlawed for anything that comes in direct contact with the enemy (as long as this planet is not one huge parking lot). And for CS/CSS why not take a truck?
6x6 is something for a constabulary and para-mil units.

Bandwagon are not so good over boulders.
So far CV90 shows the way to go.
Will see what BAE/Hagglunds SEP will do. Is it still alive?

[S-2]

Stupid idea from a guy not seriously following the discussion-

Design the vehicle roadwheels to displace adequate ground pressure and exert sufficient clearance to be towed or driven without tow on a hard-surface. Carry extra roadwheels as spaced armor ala' German tanks and Stugs in W.W.II. If the vehicle can reach a reasonable hard surface, off it goes to get the rubber band thingy replaced. Crew needs proficiency replacing a roadwheel (if lost)-not a rubberband track.

[Fuchs]

Stupid idea from a guy not seriously following the discussion-

Design the vehicle roadwheels to displace adequate ground pressure and exert sufficient clearance to be towed or driven without tow on a hard-surface. Carry extra roadwheels as spaced armor ala' German tanks and Stugs in W.W.II. If the vehicle can reach a reasonable hard surface, off it goes to get the rubber band thingy replaced. Crew needs proficiency replacing a roadwheel (if lost)-not a rubberband track.

Tracked vehicles usually only need to power a single wheel per side to move forward - and that's usually not even one of those that carry the weight, but the first or last wheel - one that merely turns the track around (sorry, I don't know the English terms). That's a very simple mechanism and this simplicity is one of the tracked vehicles' advantages.
Your system would require the roadwheels to be powered (at least one per side) - that might happen with electric drive, but isn't common today (there were such convertible tire/track combos like yours in the late 1920's and 1930's, especially the Christie designs).

http://en.wikipedia.org/wiki/Christie_suspension

Another feature of Christie's designs was the "convertible" drive: the ability to remove the tracks for road travel, allowing for higher speeds and better range, and saving wear and tear on the fragile caterpillar track systems of the 1930s. In order to allow this, Christie used very large rubber-rimmed road wheels, with no return rollers for the tracks. As with many track designs with center guide teeth, dual wheels were used, allowing the guide teeth to run between them. By 1939, the Soviets found that the BT tank's convertible drive was an unnecessary complication which also occupied valuable space in the tank, and the feature was dropped in the T-34.