Sharp hooks ( a how to and lots of argument as to their merits )

[joachimM]

And Pappy, your latest trade bow will lift off immediately in the draw, making this degree of tip flipping close to ideal for performance

[PatM]

I'm not sure how much clearer I can make the fairly simple experiment.
 You know I have routinely steered people down the more Hungarian bow tip profile because the lower angle recommended by Kooi seems to be the best compromise between stored and delivered energy. I make this type almost exclusively.

 The question is about the oft repeated statement that nobody has bothered proving. You think that you did but you smothered your test with confirmation bias. Recommending that people make sure they make the hooks huge and clunky for example.
  We already know that heavy tips smother cast but that's not the point of the test.
   
  Remember I have never said that too sharp recurves work just fine, I asked if they had ever been proven to not work AT ALL.

   I will say that sharp recurves must still hold some sort of advantage. Otherwise straight or even Hungarian type bows would shoot better than the sharp statics of the 30s and 40s that have never been approached in the  modern era.
 
 

[Badger]

  Pat, you make continuous references that todays bows cannot approach the bows of the 30's and 40's and you are dead wrong. Bow performance is based on the speed of the bow where flight shooting is the distance. They got better distances using different rules. Our arrow speeds are right up there. They had some great flight shooters in that era but flightshooting does not gage a bow, A chrono tells the story of a bows speed. My fastest light arrow bows have short sharp statics but I achieve better distances from bows much slower due to arrow tuning issues.

[PatM]

Steve, I have yet to see evidence of those different rules. They just shot wood and feathers apart from the very latter stages of that era.
  You just said that flight shooting doesn't gauge a bow and then said your sharp statics are faster. Well then it seems that those bows shoot faster AND farther.

[Badger]

Pat, I agree that the sharp hooks work very well for the speed, I am just saying flight shooting is not a good gage for a bow, only a chrono tels that story. When they strted hitting the big distnces is when they started using vanes and eleveated rests. I can get 50# bow speeds at 300 fps but much slower bows will outshoot this bow because of tuning problems. If you are talking strictly bows you cannot use flight shooting as a reference because it involves a lot more than just a bow.

[PatM]

 I still  consider a shot for distance a very good compromise when not owning a chrono.

[Badger]

You may consider it such but years of experience will teach you otherwise. If you are shooting heaver arrows it can be a pretty good guage but flight arrows won't even give you a clue.

[PatM]

 Any arrow is not going to go far if it's not going fast initially.  A really slow bow won't shoot far no matter what arrow you use.

[Badger]

  Your perception of far is what needs work Pat. A bow shooting 230 feet per second can reach 400 yards yet they usually will go just over 300 yards. A shot of about 500 yards with a 50# bow you could feel assured you had a fast bow and everything is right. With a shot of 400 yards or 300 yards or even 250 yards you may still have just as fast or even a faster bow but you simply got poor flight for whatever reason. Heavier bows shooting heavier arrows don't suffer with this near as much, once you get over 300 grains or so flight starts becomming more consistent.

[joachimM]

  Pat, you make continuous references that todays bows cannot approach the bows of the 30's and 40's and you are dead wrong. Bow performance is based on the speed of the bow where flight shooting is the distance.

Badger, thanks for clarifying what seemed to be a babylonic speech confusion.
Yes I'm talking about efficiency, not raw speed. Efficiency is the kinetic energy of the arrow divided by how much energy you put in the draw (area below the FD curve). 10 gpp seems to be a good proxy for that. And if not, it's at least what we typically shoot when hunting.
By the way, the Kooi & Bergman paper suggests that the most efficient bow design is a deflex-reflex bow with a gentle working recurve (basically aking to the duoflex design), very closely followed by a straight bow (Table 1 in that paper). 

The straight bow will not shoot as fast as the contact recurve, but it will be nearly as efficient. Mark the difference.

[PatM]

  Your perception of far is what needs work Pat. A bow shooting 230 feet per second can reach 400 yards yet they usually will go just over 300 yards. A shot of about 500 yards with a 50# bow you could feel assured you had a fast bow and everything is right. With a shot of 400 yards or 300 yards or even 250 yards you may still have just as fast or even a faster bow but you simply got poor flight for whatever reason. Heavier bows shooting heavier arrows don't suffer with this near as much, once you get over 300 grains or so flight starts becomming more consistent.

  Where did I say what I perceived to be far? You do toss around those theoretical distance possibilities quite a bit though. 

 I am fully aware of what efficient means but there are no prizes for efficiency.

[joachimM]

I'm not sure how much clearer I can make the fairly simple experiment.
 You know I have routinely steered people down the more Hungarian bow tip profile because the lower angle recommended by Kooi seems to be the best compromise between stored and delivered energy. I make this type almost exclusively.

Good, I'm glad you're still a sensible man 

   
Remember I have never said that too sharp recurves work just fine, I asked if they had ever been proven to not work AT ALL.

I've never claimed they don't work at all. The world is not black or white. My point is that the trade-off between added mass and added strain is less than optimal for efficiency in sharp recurves.
They won't work at all if they don't lift off during any part of the draw. As Badger pointed out earlier in this thread, they always lift off at some part of the draw. My point is that this doesn't weigh up to the drawbacks of the added mass.
If that's clear, it seems we are starting to agree 
We already agree that contact recurves/hungarian types of statics are the most efficient.

[PatM]

But people WERE making black and white statements and I just asked if that fact had been physically proven.
   
  I am aware of the discrepancy between stored versus delivered energy and I always bring that up when people claim that a f/d curve tells the story of how a bow performs.
 The point of sharp recurves is purely for increased performance even  when  the relative inefficiency is considered.
  That's why they are reduced to absolute minimal dimensions in an effort to harness at least SOME of the increased stored energy.

[paulsemp]

I don't think I'll ever make another static again. Too much conversation about charts and plastic. Starting to sound a lot like work to me

[Badger]

Pat the distances are not really theoretical, these are approx distances expected from glass bows shooting carbon arrows and plastic vanes out of well tuned bows with elevated rests and such.