Just about anything can be made to sort of fit on any bike. It just depends on how aggressive you want to be with the grinder.

The biggest issue with standard subframes is that they have to accomodate a rider and a pillion, so this can dictate the design of the seat, even if it's only going to be a single seat unit, as many owners don't want to start hacking away at their subframe etc.

It's also quite handy if you're a bit useful with the fibreglass, then you can pretty much cut and shut anything to fit.