Theory of limb design ?

[Ronaldlee]

Was just wondering what the original thinking was on the re-curve limb. What was the shape to accomplish and how does it work? Thanks for your thoughts, Ron

[Osagetree]

Physics?
Thinking behind the recurve theory, maybe,,, a shorter bow with smooth draw and a faster arrow speed?    
Stores more kenetic energy?
In my mind sorta like dual cams on a compound, like an extra little working 1/2 of a bow limb on each limb of your bow.... Does that make any sense?   :confused:  
Necessity is always behind the invention!  Mongols needed a shorter faster bow for horseback. Weren't theirs recurved?

[Dublin Joe]

"Because the string is under greater tension from the beginning of the draw, such a bow stores more energy early on, resulting in more total energy stored and faster arrow flight..."  Jim Hamm, TBB, vol. 2, p. 167

They're usually shorter (maneuverable and lighter) without the stacking and hand shock (smoother), and have higher poundage per length.

You can read most of the chapter on Google Books at:

 http://books.google.com/books?id=D9yQiKTtprAC&printsec=frontcover&source=gbs_slider_thumb#v=onepage&q&f=false

[4est trekker]

Yes to the above.  Also, the angle created between the string and the tip of the bow at the nock affects how efficient the bow is.  The more that angle approaches or exceeds 90 degrees, the less efficient it becomes.  Such a bow will "stack."  The less that angle is, the more efficient the bow limb is.  It's all a matter a leverage and angles.  

Consider this:  You are trying to pry a piece of concrete up using a pry bar and wedge to create a lever.  The closer you put the wedge to the concrete, the less the angle will be between the pry bar and the concrete, and thus the more efficient you're efforts will be.  The further you move the wedge back, the greater that same angle becomes and the less efficient you become.  In fact, you might just break the pry bar.

Hope that helps.

[Ronaldlee]

What would be some of the disadvantages of the Recurve as opposed to the Long Bow ? This information is very helpful, Thanks to all, Ron

[4est trekker]

Most recurves are shorter in length than today's longbows.  A longer bow will be more forgiving of form and technique inaccuracies than a shorter bow.  That is, the shorter the bow becomes, the more spot on and consistent your form must be.  That DOESN'T take into account, however, the element of centershot vs. non-centershot bows.  Combine that element into the mix and you've got a little more to deal with, not the least of which is proper arrow spine and tuning.  But generally, the above is true.

I find that recurves, although shorter and more maneuverable,can often get snagged on brush.  This is easily remedied by brush buttons, but still is a pain.  Longbows seldom suffer from this problem.

I find that recurves also draw a little less sweetly, in my opinion, in that they're storing more energy at brace and during the early inches of draw than a long bow.  A long bow, especially one with a little string follow, will pull nice and gently through the first few inches.

Also, recurves, especially dramatic ones, are more difficult to string than longbows, and their limbs are more easily twisted from improper stringing/unstringing.

Lastly, I find a long bow easier to quiet and silence than a recurve.

Now, none of these makes either bow better.  It's just what I've found to be true.  Just my lil' 'ol $0.02.    

[Jason Scott]

Well stated 4est. One just has to pick which of these are most important to them. Now, if you consider the hybrid d/r bows to be a mixture of the two... then what?