Eat2muchrice,
Have you read through heli setup guide? http://www.heli-max.net/mediawiki/in..._and_CX2_Setup

There is a lot of information in there and I've covered the reason for the blade clack in some detail. It's caused by the lower blades working the way you command (via the right control stick / servo / swash / links / lower head). The servo bone's connected to the swash bone . . . you know the song.

Anyhow, take forward flight for example. You move the stick to full forward and the rear of the lower rotor rises and the front of the lower rotor drops. That drops the heli nose and away the heli goes. But - the upper rotor is doing exactly the opposite movements because the flybar is working as it is designed. It is fighting forward flight with all the power it can muster.
OK, if you suddenly reverse the right stick, the lower rotor reverses its angle - the front edge of the rotor rises to tilt the heli back so forward motion stops. And of course the upper rotor and flybar reverse also but far more violently when you transition from forward to backward than it did when you went from hover to forward. The air speed added from the forward flight really gets the aerodynamics of the blades in hyper mode.

IMPORTANT: The *LIFT OF THE LOWER FRONT ROTOR FRONT EDGE* and the *DROP OF THE UPPER ROTOR FRONT EDGE* causes a collision of the upper and lower rotor blades.
WHACK!
Whack is clack.
Clack is death.

With the heavy stock flybar the pitch of the upper rotor blade can actually be reversed! It can push DOWN when you force it to act at its maximum potential.
Moving the control links farther out on the servo horns makes it worse.
A lighter weight flybar has less fight so the clack is reduced. (that's the whole reason for the mod. It's lighter weight and has less ability to fight the lower rotor.)
Stiffer blades reduce clack. (upgrade blades and grips)
More gentle control input reduces clack. Remember that this is a trainer in stock form. We can reduce clack, but it won't be eliminated until you go with the full performance mods.

Fly more gently and learn to fly well - then either mod the CX2 or buy a performance heli and learn to fly all over again. But next time you'll have the basics burned into your brain. Which is why you got the CX in the first place.
The reason for the flybar mod is to make a very low cost mod to a stock CX / CX2. It will certainly improve the performance. And with that increased performance comes more problems as you learn to fly on the edge. And it's also more fun. And it never ends, as each improvement increases performance - and the potential for air disaster.

We've all been where you are and you will work through it in your own way. 1)Lightweight flybar, 2) longer inner shaft, 3) Xtreme upper head (I understand that the Xtreme upper head is taller and also restricts the movement of the flybar, which should greatly reduce blade clack) Each change listed costs a little more than the prior one and probably works a little better.
Note that as you read about the upgraded helis, you don't hear about blade clack. You hear about running into things at high speed and inverted landings and more expensive breakage. But it's all good. That's why we're here.
Soloboss