I was in a spring makin mood, so I made 2 new sets. 1 set is the original Rutan springs and the other is a slightly stiffer spring recommended by another ez owner that says they work even better. I couldn't even get the shorter 5" springs on so I used one of each of the 6" springs and now it's REALLY stiff. I may not even be able to roll the trim knob without some major muscle but only a test flight will tell. :)