If you look closely, the castors are offset where attached to the 2 x 4, so when tilted they allow the 2 x 4 to tuck under the rail (because the wheels are off set). Also important is the fact that the rail is around 5/16 lower than the dolly, so basically when on the dolly the object is lifted 5/16" from the floor. It takes very little leverage to lift and lower when needed. I would think that it would work with larger, more industrious wheels also as long as they are the offset swivel type. I store my off cuts and scrap pieces of wood in large storage bins that I keep under my jointer, and I did not want to loose that space lost. This allows me to slide the bins out...or I can wheel the jointer out when needed. The casters I use are simple office chair wheels, and have held up suprisingly long.