High or heavy inflight aileron forces can be caused by the ailerons being higher than the wing.  If you hold a straight edge on the wing surface and the front part of the aileron isn't flush then you will most likely have a higher stick force than one with ailerons streamline with the wing.

Ron Galbraith

I'd be interested in hearing about this too.....I've got "heavy"
in-flight forces too....I think its abnormal.