I 'm sure this topic has been beat to death and there are probably many opinions, so lets hear them, I've heard only use one under the cup, 2 one on each end of the spring, 3 one on each end of the spring and one under the cup, "they come 3 in a pack for a reason", etc. When I put them in my last sled I used all 3 and it worked good, just bought another sled, and a 3 pack how many should I use?