How lite is Liteweight ?

My old Commander was 73 ton rated. It was double railed, Cummins, RTO 12513, 44 Rockwells, RTE 380 on alloy beams. Front engine mount/cross member was cast alloy until I fabricated a three piece steel replacement. I could get the tare down to a whisker over 7.5 tonne. The reality was ready to roll, full of fuel, toolbox, spares and my gear took it to 8.1 tonne. Cab fibreglass and alloy, except for the steel doors.

Bloke I was working for mid 70's, had Crouch's bring a lightweight White 9000 day cab poverty pack, 8V71, 15 speed R/Ranger, DS 380's on Hendrickson, and I mean basic basic!
Got an idea it only went around the 6.5 tonne mark.
Dave_64

I seem to recall and am after clarification here, aluminum chassis rails are fabricated not pressed

The Peterbilt I mention I'm pretty sure was fabricated rails not pressed, does this sound remotely right ?

Paul

Id say its very likely the rails are rolled in the U shape,.....the other method is extrusion,which is possible.......all high strength alloys have to be heat treated to develop strength................Incidentally,didja know an aluminium bike frame is heat treated five times during fabrication to develop strength......which is why weld repairs always fail.

Paul, I'm fairly certain they're Extruded & have square corners..
We were talking about the KW two piece front chassis bits the other day & swishy put up a pic of the of the Chassis of the Seattle Star which has alloy Rails ..
I can't find the pic but Shows exactly what I mean..

The alloy framed one in Wollongong I looked at had quite rounded edged compared to the US alloy chassis.
From memory the alloy rails are a lot deeper (and thicker of course) than the steel frame below.

alloy chassis 76 K125 VT903 TBB 8T





steel chassis 79 K125 8V71 TBB 8.4T

Alloy 10 stud wheels with tubeless tyres must make a considerable weightsaving over steel/iron spiders.

Yes John, alloy wheels and tubeless tyres would be way up there on the Jenny Craig list and alloy fuel tanks.
Batteries? Leyland's loved 4x6volt batteries in a very heavy box. when AEC had 2x12volt in a light frame, plenty enough juice for starts.
Centre bearing? The Leyland setup must have weighed 100kg. Short jack shaft from the box then another not much longer to the diff. One shaft on SWB worked fine.
Then the Leyland handbrake setup. All up must have been another 100kg. Huge lever with linkages all the way to the air assist cross member and finally down to the brake boosters. A couple of maxis plus tank was way lighter.
Modern alloy front bars must be streets ahead of the old hot rolled channel and fabricated steel uprights.
Finally the spare tyre frame. Some wonderful designs there and typically the first item to get ditched when a turntable is fitted.

4th time lucky trying to reply

Hayseed you are probably 100% correct I recall that the Peterbilt I looked at had square edged rails unlike a normal pressed rail

A lot like roKWiz photo's, tah muchly for them

John I didn't know that about treddly frames and have really paid them any attention since getting my license :huh: :huh: :huh: :huh:

I reckon 10 stud alcoas and tubeless rims would have to make a huge difference, I wonder how they compare with alloy spiders and tubles rims

Jeffo the old battery x 4 weighs a bit, even times two weighs a bit

I know in the states you could get alloy airstart tanks for Macks, I doubt they sold many air start trucks let alone with alloy tanks, the reason I say that is they aren't much chop below freezing in my experience as the big air valve freezes up

Maxwell Ultra capacitors are apparently all the go these days, deep cycle batteries, (probably lithium now) to run the heater in the bunk when snoozing and it can run until completely flat and the Ultra Capacitor to start the truck


Alloy air tanks as well, mind you air tanks arent very heavy

Definitely worth exploring further

Paul

I see the capacitor at the end of that video 3000 Farads, most used in electronics are in microfarads. I'm a bit surprised there isn't more of this.

Jarrod.