Changing Tire on Dual Axle Trailer using Small Ramp

otrfun wrote:
Noticed a small, plastic ramp for changing out tires on a dual axle trailer at a local trailer store. By driving up the ramp with one tire, the remaining tire (on the same side) supposedly gets lifted off the ground just enough to allow the tire to be removed.

The ramp is about 18-24" long and only 5 1/2" inches high.

Do these things work without a lot of drama? If so, was thinking about fabricating something similar out of some 4x4's.