Goldslinger,
I haven't done the math, but from my fiddling I found that there are two ways to get stability out of the flybar. Taken to ridiculous extremes, you could run a super short flybar with a ton of weight on it and get stability. But the weight of the heli goes up - and the weight is carried above the rotors. That seems like a bad idea. The other extreme method would be to run a very long fly bar with very little weight on it. Because the flybar "tip speed" is greater (spins in a larger circle) you need less weight. And the longer flybar has more leverage.

I was going to go to a longer flybar by sliding the weight and boot up the flybar and straighten the bend. Then remove the junk and use one collar with CF tube over the full length. If I needed a bit more weight I'd add shrink sleeve over part or all of the length. Possibly, a coat of epoxy over the length of the longer flybar - then slip the CF tube over the entire length would be enough with no collar at all. If not, add shrink sleeve over the last inch or two or three or . . .
Anyhow, I'd think we can get the spinning weight that we need without the 'lump' at the end if we run a longer (but very svelte) flybar.

your thoughts?