I've been working with a Sabre over the last few weeks. It's a 1948hv and seems to work pretty decent. Tonight when I was showing my son how to run it I found it has an interesting problem. When the seat is cold the vinyl doesn't flex enough under his skinny butt to activate the seat safety switch which does function correctly. So now I have to bypass it. The switch works fine when it is above 60 degrees out.