Blade Specs

But by moving the cog further out you effectively make the rotating mass of the blade heavier

No extra weights needed.

The chordwise c of g is further forward on FBL blades too

Very few blades have those specs published and I suspect it's mainly because very few people want to know those things.

There is also considerable mystery out there about FBL vs non FBL blades and it seems that there's this notion that if you have a flybarless heli you must have special flybarless blades. I have flown FBL helis with regular blades and flybarred helis with FBL blades and for my style of flying the differences are not nearly as great as one might think.

I recently did a comparison between standard Radix 710s, Revolution flybarless and Radix FAIs. Between the standard Radix and the Revolutions there is very little difference, only a few grams in overall weight using the pairs I happen to have but I also know that the weight of Radix blade pairs varies quite a bit so you could easily get a pair of Radix that weighs more than the Revolutions (we're talking about 193 vs 196 grams, not enough to even notice in flight). The Revolutions have a spanwise C of G slightly further outboard by about 1 cm. The chordwise C of G (judged by the distance of the bolt hole from the leading edge) is about the same.

I haven't flown those two pairs back to back to compare but I wouldn't expect much difference. The Revolutions are a few mm narrower chord so I'm not sure what effect that has in the feel.

Compared with those two the Radix FAIs are way heavier AND much further outboard C of G as they're intended to be as stable as possible, so in reality they are 'more FBL' in terms of the general differences between FBL and normal blades.

I'd also hazard a guess that there's less difference between brands than people would have us believe. Just my opion of course.

Yeah I think this is true. The reason is that there are just certain 'sweet spots' in any of the specs that make a blade work well. Within a certain range you can have some variation but cannot stray too far from what is known to work.

A while back I started thinking how the heck can you try all these blades, there's so many out there and most claiming some advantage or another but I think the reality is that the science of it is so well known now that among the top brands you may as well just choose based on looks.

I tend to go back to the standard Radix blades as a benchmark because it seems they really got it right. I have not tried the Spin or Edge blades yet and those seem well liked so I might give them a go at some point.