Smoothness of Draw...

[Longcruise]

No fixes.  Converting from PNG to JPG made the data points difficult to see.

[williwaw]

sorry to hear that Rich.  Here is some reading for later.

https://www.ocf.berkeley.edu/~archery/wp-content/uploads/docs/recurve-fundamentals.pdf

 a couple of excerpts.....

Olympic recurve bows appear to be a hybrid between a long bow and a traditional recurve
bow. While the tips of an Olympic recurve bow retains the general shape of a recurve bow, it is
also longer that a traditional recurve bow, but not quite as long as a traditional long bow. The
rather unique geometry allow the Olympic recurve bow to exploit some of advantages of energy
content and efficiency of traditional recurve bows, while maintaining some of the advantages of
stability of traditional long bows.

the smoothest part of the DFC can be moved further back in
the draw cycle by making the recurve part of the limbs deeper. Under crude observation, the
smoothest part of the DFC will likely appear in the part of the draw cycle when the tips of the
limbs are nearly vertical. Beyond this location, the limbs tips will begin to orient themselves in
the direction of draw force, and stacking will begin.

[Mad Max]

When are you going to give us the answer ????????

[Longcruise]

Interesting read Willi.

[OldRawhide42]

Williwaw thanks for that info. I have been looking for that kind of stuff for a long time.

[Shredd]

  Ok...  Here is the way I see it...   I hope I can explain this like I see it in my head...

   First lets define stacking...

   Traditional / Archer's definition...   It's the increase of poundage per inch compared to the last inch before it and usually starts occurring at or near the end of the draw cycle...  It can be felt by the archer as more and more resistance builds up per inch... 

   Bowyer's definition...   It's the increase of poundage per inch compared to the last inch before it...  Usually starts occurring near the 20" mark of the draw cycle of your average bow size...  60 to 64"

   Draw Smoothness...

In the info that Wiili posted from Berkeley...  They talk about smoothness of draw and moving the smoothest location back more on the draw cycle...  They show extreme DFC's of Olympic recurves...  Granted when you have a curve that big and most of the weight is gained in the beginning of the draw cycle you should be very smooth at the end of your draw...  They talk about stacking and stacking less for a smoother draw...  Granted stacking does contribute to a smoother draw to some  degree and to a larger degree on a more extreme RC I feel that they are off base on most of your standard bows...  I feel something else contributes more to a smoother draw than simple stacking in the last half of the draw cycle... Depending on the amount of stacking, I don't think that the average human will feel a difference in stacking unless it was a huge difference in numbers per inch, like the stacking you would feel at the 31 to 34" mark on the bow of average length...

   Here is what I found...

   Being that we don't have numbers on the Berkeley DFC's we will use the ones we started with and mine to compare...

     If you look at the dark green columns, that the 20" to the 28" mark of both bows you will see the stacking is very close...  If you look at the two curves that Cruiser supplied, the curves from 20 to 28" look very very close... In which they are...  I added up the numbers in each Dark Green column from 20 to 28" and came up with a difference of .07#...  The longbow stacks .07# higher over 8" of draw...  If spread out over 8" that would be less than .01# per inch...  I do not think anyone is going to feel that...  I think we can rule out that  standard stacking or our definition of stacking as the overall or root cause of smoothness of draw on a standard bow...

   Now look at the blue columns...  That's where I see the biggest difference...  I added up the blue columns from 20" to 28" and came up with a 1.84# difference between the RC and the LB in which the RC was the lighter one...  That's almost 2#....  Do you think you would notice a difference if one bow was two pounds lighter than the other...  The confusing part that I cannot wrap my head around is that each bow weighs close to the same at 28"...
   I believe what is happening here is the curve is like a see-saw...  What ever happens in the first half of the curve is reflected to the second half of the curve...  You can go back to the percentage column and say the percentage of weight is stacking slower or is it??  I didn't do the numbers on that but I don't think it is...  What is happening is the blue column from 20 to 28" of the RC is simply much lower in weight than the blue column of the longbow... And that my friends is where you feel your smoothness of draw...  It like you cut the DFC in half, took out the 20 to 30" section of a 43# bow and replaced it with the DFC of a 40# bow.... Yet it still weighs 43# at 28" draw because of all the weight built up in the beginning of the draw...

   I was always under the impression that smoothness of draw was directly related to stacking and I think just about everyone else out there thinks so too...  Even in the Berkeley stuff they show angles of the DFC and say stacking is directly related to draw smoothness...  But I feel it is more or less related to the building of poundage in the beginning of the draw where the RC is about 2# heavier then transitions into a smoother like feel draw because even though the weight of both bows are stacking at very close to the same rate the RC is much lower in weight through the last half of the draw cycle...  And when you transition from a higher weight to a lower one it's gonna feel like it draws smoother...

So the RC starts off heavy at 17" and draws real light to get you to 43#...

  And the LB starts off light and draws heavy to get you to 43#...

   I believe the stacking is pretty much the same because of the geometry of string angles and such...  Once the string leaves the limbs on the RC you are pretty much in the same playing field as the LB....

  In conclusion I think stacking is a different animal than smoothness of draw and is not always directly connected to stacking as a definition as we know it although on some bows it may make more of a difference...

[Roy from Pa]

Rich sorry to hear about your friend.

[Roy from Pa]

Don, I like the way you think..

 

[Mad Max]

When are you going to give us the answer ????????

When are you going to give us the answer ????????

[mmattockx]

So the RC starts off heavy at 17" and draws real light to get you to 43#...

And the LB starts off light and draws heavy to get you to 43#...

This is a significant effect. The human body is very sensitive to small changes in load increments and would start to notice stacking occurring almost immediately towards the end of the draw. You could well be correct that the smaller increments on the recurve give us the perception that the recurve draw is smoother. That is certainly my perception of drawing one.


Mark

[Shredd]

  Don... I can't disagree with most you have to say...  I guess you have to shoot a recurve and a longbow and see which one fatigues you first, if at all one does... Or maybe one doesn't have to fatigue you... You may just like the feeling of how one draws better than the other...  Or you may not even be sensitive to the draw cycle where others are... You say they are both 43# and either way you are pulling back 43#... I agree... But there is no denying that the RC is 2# heavier at mid draw... Now its all all about body mechanics, muscles and geometry... Smoothness of draw may seem like an illusion... but is it really??  Who knows, depending on your body you may tire first from the RC...
   As I said before the bow with the biggest percentage in the beginning and the lowest at the end will usually get you the fastest arrow... I sell this concept all the time and that's why I concentrate on making a fast bow... Why pull back on a 50# bow if a 40# is faster??


Thanks for understanding, Mattock...  At least my sharing all this work was not in vane...  The bottom line is I broke the myth that smoothness of draw is directly related to stacking...   There are other factors involved that can make a bigger impact... 

For Mark and Roy... Sorry guys... The answer is in Chinese...   

[Shredd]

 Alan...  If you want to chime in, I would like to hear your thoughts on this... Maybe you could tell the story of the extreme case where the flight shooter could not draw back the bow because he was not used to the draw cycle and body mechanics maybe came into play...

 Thanks on the friend passing thing, guys...

[Shredd]

  First let me state that this thread was not intended on whether the feeling of smoothness of draw is good or bad or less effort or fatigue related... That can be a topic for a whole other thread or if you choose you all can debate it on this one...  I myself am not real familiar on this topic and would be more or less theorizing if I stated something and that could lead to false things...  I am simply stating my findings and you can choose how to use that info in any way you choose...

  In my time as a bowyer I have not seen much discussion on smoothness of draw... It only came into my interest in the past week when I shot a RC and a LB of the same weight and the RC had a more relaxed feel to the draw...  So it peaked my interest and I started looking at the DFC's...   It is my assumption that most think that is is directly related to stacking and that's about it...  Plus for the fact few if not hardly any have accurate DFC's so hardly anyone could pick up on the difference between stacking and lighter draw numbers...

   So my friend...  If you can't comprehend this, it's ok...  I still have to wrap my head around it also...  You may want to drop it and then a year or two later you may want to come back and look at the numbers again...  There is no denying that 43# is 43# but there is also no denying that the RC is 2# heavier at mid draw and there is also no denying that when I drew back my recurve it had a different feel than my longbow... Like I said if one is less fatiguing than the other it all has to do with geometry and body mechanics and that would be a whole study unto itself... So take these numbers and get out of it what you can... And just know that if one bow feels like it draws smoother than another you now know what is causing it... I am in no position to offer you more than that... Plus I also did not research a whole slew of bows that are out there...  Just remember this, The numbers don't lie and they are a direct result of what is happening in the bow limb that can help you further understand how a limb works and with is info it can help you design a better performing bow design of your choosing...

[williwaw]

Rich,
 
Do you release when the clicker tells you to?

from page 48,  http://ocf.berkeley.edu/~archery/wp-content/uploads/docs/recurve-reference-guide.pdf   

When you get to anchor it is very important that you don’t stop pulling. Changing from a “pulling”
action to a “holding” action will make it very difficult to return to the pull, and so the arm muscles are
likely to tighten up – this makes it EVEN MORE difficult to pull, and so it becomes very difficult
(sometimes impossible) to get through the clicker. If this happens COME DOWN. Don’t struggle – it’ll
only make you tired, and may result in a very poor score (even a miss!) if you do manage to get the shot
off.
We can draw from the bow all the way back to the anchor, stop and all of a sudden that last 1/16”
becomes so very, very difficult. Keep moving, albeit very slowly. The action of pulling, even slightly,
will keep the muscles in the “pull” configuration, and suddenly the clicker will be a piece of cake!
Finally – the aim. The answer here is DON’T. This is another concept which will upset beginners...
how on earth do we get the arrows near the target if we don’t aim?? Well, quite simply, we do, but not
consciously. Let the sight float around the gold. When the clicker goes off, and the release occurs, your
brain will automatically centre the sight on the gold... all you have to do is set the shot up correctly, and
let your subconscious do the rest.

when shooting like this, could it be that last 1/16th of an inch might be where the smoothnesss, or rather, the bodys perception of it makes the difference?

[Longcruise]

  In my time as a bowyer I have not seen much discussion on smoothness of draw... 

Go visit the "Wall" and read any new bow report.  They are all "smooth" 😀  I think it's the most used and abused term in describing a bow.  OTOH, it's possible that "stack" is a close second.

I had trouble with your presentation due to your use of the term "stack" to describe the variations of the feel of the draw at points where the traditional Bowyers definition of the term is not applicable.

But eventually I grasped what you were thinking.   I don't think that the variations in the rate of draw weight increase throughout the draw cycle are at all pertinent to an archers ability to draw comfortably throughout a long course of shooting. If the shooter is having trouble staying with the draw weight then the shooter is overbowed.  Other than that,  our muscles rapidly adapt to handling the variations in a draw cycle when practice is regular and adequate.

I can't imagine any serious competitor allowing themselves to be overbowed so that group is probably very unlikely to be concerned over minor variations of draw cycle from bow to bow assuming that they have selected a well designed bow in their preferred style.

[Shredd]

Willi...  I have not used a clicker...  Thanks for the info you supplied...  I learned some things from it...

  Cruise...  What I meant by the bowyer's definition was that we recognize (or we should know)the weight starting to stack much earlier on the draw cycle (around the 20" mark) vs the traditional term or meaning for it... 

[Shredd]

Just posting on here so it gets to the top of the heap as a recent post so a friend can find it...

  Ok...  Now you can go about your business...