The easiest way to adjust a stirrup/ speed bar combination is to extend you legs and lean back. Adjust the bar so that your legs can be locked straight, comfortably. If you can’t straighten your legs, it’s too tight. If you have to point your toes, it’s too loose. Then, make the speed system line as tight as it can be without engaging any speed system at the riser. That’s as good as it gets.

The progression is; one foot on the line for a little speed, two feet on the line (pushed to the bar) for some more speed and two feet on the line with the bar hanging down for almost full speed.   

Absolute full speed is often achieved by pushing the speed system line to the sides and down.

Some people take off with the bar between their legs for guaranteed access after takeoff. Others, use a “push button stop” to pull their speed system up and out of the way for takeoff. The stop slides easily when the speed system is actively engaged.