By Phil Geren
Of all the go fast stuff I have learned from tuning experts over the past year, the most valuable, and the thing that has provided the most additional boat speed for my 13#-3.5oz Star 45 (the "Fat Lady") is how to get the Jib's topping lift set right. I am doing much better in my racing since learning this.
The curve of the leech of the Jibsail MUST resemble as closely as possible the curve of the leeward surface of the Mainsail when sighting from the foredeck. If the Jib's leech is flatter or fuller your boat will not attain its speed potential while beating and reaching.
The topping lift enables you to get the curves aligned. Tightening the topping lift makes the Jib's leech fuller, more curved. Loosening the topping lift makes the Jib's leech flatter. With a little practice you can get the curves to be identical.
Here's how:
Pull the Mainsail in to the beating position; Swivel the Jib boom with your finger (apply only lateral force, no upward or downward force on the Jib boom) so that when you sight from the foredeck and look up and down the curve of the windward surface of the leech of the Jibsail it is superimposed on the curve of the back (leeward) surface of the Mainsail.
Are the curves identical? If not, is the Jib's leech more curved?
If it is, loosen the topping lift.
If the Jib's leech is flatter, tighten the topping lift.
Make small adjustments. This is very sensitive, and you can get it right if you persevere.
Recheck the need for adjustment after every few heats of racing or if you change anything else.
On sailboats EVERYTHING is related to everything else, and you will need to readjust periodically to maintain your added speed.
Don't have a topping lift? INSTALL ONE NOW! You won't believe the improvement!
