A shorter flybar is a must if you are planning on increasing the preformance of a CX2 by moving the servo horn positions. I was also on the receiving end of clack a time or two as I progressed through my CX2 comfort zone. I ended up modding my flybar to a shorter length and adding bullet weights on the end. I now have my servo horns on the very outside hole on the elevator and the 4th hole on aler. With the shortened flybar I can almost not get my blades to clack. I have not spaced my blades apart with a lengthened shaft as is said to be a requirment. It's not. A shorter flybar is. You can order a shorter bar from
www.boomtownhobbies.com that approximates what I did to mine.
Good luck.
Uri