Cabovers

US trailers are generally with tandem and weight distribution is ~50% on fifth wheel ~50% on rear axels of trailer. EU trailers are of 1/3 on fifth wheel and 2/3 on tridem, so we cant use US trailers here with EU 4x2 trucktors, so we have to use made in England 6x2 and 6x4 cabovers with US trailers to follow the axe load directives.

US trailers with more load on fifth wheel force sliders and longer wheel base to follow the axe load limits.

If you try to use EU cabover in the USA you have to use EU traler ore make EU cabover on longer wheel base. of cource 6x2 ore 6x4. So there would be some room for drometry box ore longer cab.

The other way - move front axe forward but loose entrance steps. and make entrance in Renault Magnum stryle. Iveco did it on Aussy market

 

Listen man!
You are a well informed man, but in this case yor're making errors.
That K500 is a specialized truck only to be used in off road applications like in the oil fields. It has heavy off road (over width) axles, a super reinforced high profile structure. The engine is positioned high above the front powered humangus diff steer axles, and everything else on that truck doesen't resemble anything to a on road truck. As anything else, the only thing on that monster that resembles a highway truck is the DAF cab. They might've just installed an outhouse box in top of that frame just to kip in the same appearance with the rest of the KW design. They simply destroid the image of that good looking DAF cab with the crap works from underneath it.

The ISX cummins engine has a very low profile with the double overhead cams design. Vertically it's not taller then Volvo engines, nothing more that what the already engine clearance provided in most EU COE's equipped with in line 6 can handle already.

 

What about a rear lift/steer axle, I had one of those, drove like a dream and you could easily shift the weight around with the touch of a button

 

Sure, the limit here for a regular front axle with regular radial tubeless( tread 4 seteel plyes and 1 sidewall ply ) 11R22.5 tires is 12000lbs. The Volvo VN's are already at 12500lbs wen bobtail and has a 13500lbs rated front axle.....and they're tolerated so far with just regular 11R22.5 tires.
They could install a 17500lbs in a set back front axle Cabover and use 315/80R22.5 tires (315/70R22.5 are not available here yet)
But that'll be to much trouble for the guy that is stuck only with what he knows and can't handle anything new.

 

Really I'm not sure about ISX dimentions. XF cab is of the same dimetions like was 20 years ago and as I remember N14 fits XF. If ISX is not taller N14 - no problem, but seems to me ISX is a bit taller.

K500 is a fat truck, I saw them on NG tube works, and as I saw they are with non highway version of ISX w/o DPF, but with CM 871 ECM. A bit wierd combination.

 

I wanna say about one more insane cabover - Tatra. They joined Paccar too, so Tatra got DAF cab and Paccar powertraine, but they make unique independent suspention, very good in mud.

The problem of this suspention is uneven tire wear, but with ECAS they solved this issue

 

Just thinking out loud here: wouldn't a rearlift axle with weight distribution solve those issues? Do ye use supersingles on the steers there?

 

Usually you're getting allot of things right, but today you kip on sticking your foot in your mouth, son!
EU 6X4 tractor coupled to a us trailer would have at least 6 to 8 feet of empty fraim rails. US trailer kingpin setting is at 3' (front trailer to kingpin). The trailer don't even cover the front drive, just half way maybe. Usually the fifth wheel is positioned in the middle in between the drive axles, to kip from transferring any weight to the front in the case of tractors with set back steer axles like the V VN.
With the classic set forward long nose trucks the fifth wheel is positioned as far forward as clearances would allow in order to transfer some weigh to the steer axle.

As for room for drometry.........do your geometry pall. The further back the kingpin setting is like on the EU trailers, the longer the radius, the less space required between cab and trailer (when coupled and in straight line) in order to clear the corners in a turn.
Vice versa, a US trailer requires a larger spacing between cab and trailer, cause of the short radius, in order for the trailer corners to cleare the cab in a turn.

The axle weight distribution 50/50, 30/70 or whatever, is according to how many axles and where they are placed. There are short wheelbase day cab tractors here, shorter then a 6x4 EU COE. No worrys about that, mate!

 

The N14 is aprox 6" maybe 8"(N14 plus) taller then the ISX.

 

Yea, there are super singles, and yes they're used in steer axles, but not the very wide ones that are intended to go on drive axles.
There are lift axles available as aftermarket solutions, or on special orders, but in some states you're not allowed to activate them from the cab. Can't play with lifts and dump valves on the scale to fool them. That's a No No.