Steve,
When you wait to stick it in third gear, letting the RPM's drop before you do so, you are in essence double clutching...without using the clutch. If the output gear is turning the same speed as the input gear, no grinding will occur..you have matched the gears in rotational speed. Technically, you could shift without using the clutch merely by matching the speed of the two gears. Truckers do this often.
Stuart
