Hi BB,

I'll have a go as well....

I think it all comes down to the following... On flat ground, would you rather carry 100Kg on your back, or in a wheelbarrow?

Relying on some very old physics lessons, it is well accepted that it takes far more energy to get something rolling than it does to keep it rolling... I think that the difference in work required by a horse in dragging around a 60Kg driver vs an 80Kg driver is marginal... probably much less of a factor than "barrier" draw, and where the horse gets to sit in the running..

I also think there is a lot of merit in the "momentum" comment... I often notice drivers "swinging" in the sulky... I can only think that the reason they do this is that they're trying to get the horse to run even faster by "pushing" it along....

At the end of the day, a driver's weight is probably factored into their "ability"... often you can get a winner simply by weighing up the drivers and the draw, as opposed to looking in depth at the form.

Cheers,
Chris.