First thing we need to think about with a tail setup is when you try to pitch the blades to rotate the helicopter is that air is going to want to try to force the blades back straight. Kind of like trying to move a boat paddle in the water. If you have the skinny side going into the flow of water, there is little resistance and you can quite easily hold it. If you then start to put pitch on the paddle, it gets harder and harder to hold the paddle in the same position. This is the same struggle that a servo has when trying to move the tail blades.
Insert the chinese weight mod. The added weight adds centrifugal force to the tail and it also creates it's own drag, which when paired together, help the blade turn in the air, making it easier for the tail servo to control the tail.
Then there is the picture above. This, although less weight, has a flatter surface which catches more air to assist in keeping the blades where they were told to go. Less stress on the servo.
Granted, this is not a lot of force for a 450 size helicopter, and you don't see it on any of the larger helicopters, and all in all it is a mildly pointless mod, but the theory behind it is sound and does work. Just not enough to really matter. Kind of like the KFM Airfoil..... Yea, we won't get into that here lol
