If you REALLY want to make your boat slide out there, replace your
black rubber keel rollers with those translucent yellow-tinted rollers.
Be sure and grease the roller axles while you're at it, too.

Your boat will roll off the trailer like somebody was towing it off. In
fact, you need to be careful, because when you're backing down a steep
ramp with these, a MUCH greater proportion of the boat's weight is
pulling on your winch cable/strap, to the point that it might break,
with your boat rolling off onto the concrete.

It can also make it harder to get your boat out of the water, because
when you drive it up onto the trailer, it wants to just roll right back
out the instant you turn off the engine.

Ron M.