Are you concerned about restraining the wheel from lifting? I suspect you might need a double track, basically, a square cross section set on its corner, with a wheel above and a wheel below.
If you mean the difficulties of locating a second parallel rail, also with V type construction, just use a flat track / flat wheel for the second rail.
FWIW, I don't really like the Vwheel track design, because it forces track or wheel wear. The V obviously has many different circumferences, which creates a range of circumferential speeds. Obviously the whole surface of the track moves past at one linear speed, so something has to got to give. I'm not sure if the wheel wears out, or the track.