[fuzzy]

i have an idea for the sled let's see if i can say this right

1)make your weight that you want to slide up the sled

2)get it on some sort of track so it goes straight and doesn't put more weight on one side of the truck and so it won't fall off

3)use your fishing line and tie one end to the weight, then string it around the front of the trailer, then tie it to the axle on the trailer with a small sppol or something.

4) you're Done

as the axle gets pulled forward with by the truck it will spin and twirl the line up and pull the weight forward to give the truck more resistance as like a 1:1 sled would

let me know what ya think!