We have two game carts, both 2-wheel, one an older (but very light) model with side-by-side wheels. It weighs less than 20 pounds, so is pretty convenient there, and the frame is long enough that a deer or antelope or elk quarter/half can be easily loaded. But even though the the wheels are only 16" apart, and the center of gravity is relatively low, it doesn't work well on even relatively gentle mountain trails--except for closed logging roads.
It also came with bicycle type tires, and when they eventually wore out (partly due to lots of trundling antelope across prickly pear), found the same size could NOT be found anywhere. So found some solid-tire wheels of about the same size, which required some machining by gunsmith John McLaughlin to fit the axle. (John is a hunter, along with being a great machinist/gunsmith:
www.mclaughlincustomfirearms.com)
Seven years ago bought a neetkart (
www.neetkart.com), which has two in-line wheels, a much heavier frame, and bicycle-type brakes. It can also be equipped with another set of handles on the front end. Unless the animal is under 100 pounds it only works well with two people, one at each end--but then it works really well, both on flats and on narrow mountain trails. Have hauled out stuff from two pronghorns to a halved cow elk with no problem. (In fact, it has now been adopted by a number of search-and-rescue crews to get hurt humans out of the hills.) You could do far worse than look at its design.
