Originally Posted by Brian Ratliff

This is a bit tougher problem because there are significant secondary effects. On first glance though, at the same speed/same corner, a heavier person needs proportionally more cornering force as the lighter person. However, the heavier person has proportionally higher traction as well. First order estimate: it's a wash.

That said, a heavier person is also less affected by surface irregularities while the lighter person doesn't have to "groove" as hard into the corner (they can change their cornering path more easily) because they have less momentum. The heavier person doesn't bounce around as much and can push closer to the edge of traction. Whereas the lighter person's wheels will start chattering as they approach the edge of traction, the heavier person's wheels will be stuck to the ground right up until they wash out.

All in all, I think it will be the case that the heavier person can corner somewhat faster, but the lighter person has somewhat more margin for error.