School me on truck frames- do they twist?

They are designed to twist. That's one reason they don't want you welding on the frame as it's heat treated for strength. When you have 500HP on a rotating shaft transferring to an axle, something has to give. All them rubber bushings and mounts play a role in cushioning the transfer of force.

If you plan on off road, it is very easy to get one stuck on flat ground with a small rut if you are sitting on it. I would think a single axle would perform much better than a dual because there is no dead axle to lift the drive wheels off the ground in changing terrain.

 

there are plenty of shops around, where exactly are you?

 

A single drive is better as Long as the ground beneath is sufficiently solid to support it, on snow and ice a rear lift axle has far more traction than a dual drive, that's the reason most trucks from the Nordic regions are rear lift and when they have dual drives the rearmost axle will lift on that too, they are pretty good of forestry roads too but you can't beat a dual drive on lockers if the ground gets soft.

I would imagine that your chassis would have more flex than ours cos of the length of your chassis , ours are quiete short in comparison which would limit the amount of flex we could get.

 

Take a look at this, http://www.westcoastframe.com/ , Sacramento,Ca boys nice set up.
J-J

 

Interesting

 

your on the right track, the longer a frame is the more it will flex the shorter it is the stiffer it will be.

 

reaaly there are enforsed frames for oil field trucks and log trucks, for construction trucks, like KRAZ, Volvo VHD and FMX, and some other you cant feel its twisting, but off road frames are so heavy!

 

some are also doubled or box framed as well. Talk about a rough riding and HEAVY sumbeachin truck that is.