Yeah Denny, I tend to agree that if there's no price given then either "if you have to ask, then you can't afford it" or they just don't actually want to sell it anyway.  And looking at the page of that innovative new bow design, uhh.. I can't make out enough to figure hide nor hair of how it could do what is claimed, so I probably wouldn't want one anyway.  LOL

Logically, it is just physics that moving the frog is going to make some difference.  But thinking of it as a lever and the movement being on the heavy end?  Moving the frog a few mm may only move the balance point a mm or maybe even a fraction of 1 mm.  Such a slight difference that it wouldn't be noticeable under any normal playing circumstances.  Maybe a really good player could tell, but I wouldn't be able to.  So for all practical intents and purposes, I'm good with the idea that it doesn't move it enough to make any important differences. 

It just seemed odd to me that most balance point references seem to refer to distance from the frog when it would seem to me to be more sensible to measure from the tip, which doesn't move rather than the only moveable part on a bow.  That way there is no need to wonder about how to actually make the measurement in the first place.  But what do I know?

At the risk of boring the dickens out of some members..

Fiddlestix.  Do you honestly think that any time someone does not agree with you 100%, that they simply didn't read what you typed??  Relax.  LOL 

I agree with you 99.9% on the actual point of it not being enough of a change in the balancing point of the bow to likely matter to anyone.

The tenth of a percent that I disagree is that it does change slightly.  Here we have a bow (most of one anyway) hanging from a thread with a yardstick to measure the difference when the frog is at both extremes.

That is not much of a change.  About 2 inches of tilt.  The thread only needed to be moved not even an entire 1 mm to bring it back to the same equilibrium between the frog being at minimum and maximum adjustment.

So there is a difference.  But it is very small.  Considering that the difference between a loose bow and a taut bow can be less than one turn of the adjustment screw, it probably isn't even moving the frog more than a mm or 2.  So the actual balancing spot of the stick would be changing by only a tiny amount, some small fraction of 1 mm.

That is a difference that is so slight that I rather doubt that even most professionals would notice it.  I'd have to see it to believe it.  It would be considerably less than the difference adding or subtracting less than even 1/10th of a gram from the tip would make.  

The only instance I can think of where it might be even slightly noticeable would be if a bow with hair that was very stretched out was re-haired.  The frog might be a few mm different than it was before the re-hair (though the overall balance point would not move enough to notice when playing even then).  Far more likely that they would notice the slight change in distance from the frog to the leather wrap.

So, considering that approximately 19 cm is what the one authority considered optimal, I doubt anyone would decide to buy or not buy a bow if it is a mm or 2 away from 19 cm.  It would be close enough. 

So I agree 99.9% with you.  Which in my book is close enough to call 100% for any practical playing purposes.