Runner crown "flat" relative to the steering pivot. I assume this means the flat is too far forward.
Aside: I think a pivot point forward would give weather helm, and aft would give lee helm. (?)
Think about this - if you put a runner with crown on a surface plate, it will touch the plate directly under the CG. It can't do anything else without a little help.
I agree. Of course, the there is a "little help" from the weight/force on the front of the boat pressing down on the pivot bolt. Even with my relatively heavy plate steering runners, I've always believed that there's more than enough force on the steering chock while sailing to rock the steering runner so the contact point is directly under the pivot bolt (absent a mechanical interference like the chock/stiffener contact). I've seen it first-hand when checking runner profiles on a stone, the contact point is essentially directly underneath the point where one presses down (assuming one applies enough force to overcome the runner's weight distribution).
OTOH, I'm adhere to the maxim from Sherlock Holmes, "Eliminate all other factors, and the one which remains must be the truth", so at this point I'm unwilling to categorically state it's impossible for the shape of the steering runner profile to affect the helm feel. I'm pretty sure I don't have a uniform radius curve along the length of my runner, so even through there isn't any "true flat" area, I think there is a region near the center with less curvature than the lead-in and exit sections. Could this be significant? I don't know. The experiment proposed below would seem to be the answer:
Has anyone tried taking a front runner from a boat with lee helm and putting it on a boat that didn't have lee helm? Or the opposite might be even better - try several different steering runners from a boat without lee helm to see if it makes a difference on a boat with lee helm . It seems like this would be the easiest way to isolate the influence of the steering runner on the lee helm problem.
I've not tried that in an immediate sense of swapping runners on the ice, but I'll give it a shot when we have ice next year.
What I
have done is use the same steering runner that I had on my older hull (neutral helm) with my new hull (lee helm). I don't remember any re-profiling between the two seasons (I doubt I did anything because I was busy building the new hull almost the entire off-season).
Cheers,
Geoff S.