Prolly a dumb question, but...
...Have you tuned the rigging? By creating the right amount of mast rake (and placing the mast "properly"), you can minimize the amount of weather- (or lee-)helm, which in turn tends to minimize the amount of force on the tiller.
(But you already knew that, dincha?)
jb4
"So don't pay attention to the approval ratings that say 68% of Americans disapprove of the job this man is doing. I ask you this, does that not also logically mean that 68% approve of the job he's not doing? Think about it. I haven't."
— Stephen Colbert, at the White House Correspondent's Dinner 29Apr06