the pivot point of the load?
I was bringing some shopping home in the kid's two wheel trailer we have, and though it wasn't that bad, going up hill, there was a lot of resistance.
After I'd unhooked the trailer at home, I wheeled it into the garage, load intact. I noticed that when I lifted the trailer by its attachment bar, as the load moved from in front of the wheel to above it, it got lighter and easier to move.
Would the same be true if it were attached to the bike like that, or rather, if a trailer were designed not with the wheel at the back, but with A Wheel more central, so the load could be placed over it, rather than in front of it?
I'm no expert, but I seem to remember the basic principle of loading a wheel barrow is put all the weight over the wheel. If that is the case, why do so many trailers have the wheel right at the bacK?