The way they're made, with a heavier head on one wire & a lighter head on another wire, supposedly it would ride upright ... with the heavier head underneath. I've only tried it once, and it would only ride that way at a VERY slow pace. Otherwise they'd pretty much run sideways (side by side). Not that that's a "bad" thing, mind you, just an observation I made on the one & only trial run I made with them.