the "D" shape R/D longbow appreciation thread!

[Moots]

Beautiful bow Ralphie!

[Ralphie]

Sorry guys
will repost once I figure out what went wrong with my file size

[Ralphie]

try




sorry about the sideways view still working on how to post.

[Ralphie]

double post sorry

[Rob DiStefano]

nice bow, ralphie  

[**DONOTDELETE**]

Originally posted by pavan:
Then the next question, for a 5'9" (and shrinking) short draw shooter like myself with my little 26" left hand draw length, how much performance difference is there between the 62" bows that I have compared to a 68" R/D? What would happen to the shooting qualities of an R/D bow that was under-stressed at full draw because of its longer length? The Driad boys seem to think longer will always out shoot shorter. That does not seem to be the case with Hill style bows, although I have seen some exceptions to the rules with those, such as, an under drawn bow can have more hand shock.

This is a really good question bro.... i'd like to shed a bit of light on the subject if you don't mind....

I'm uncertain where you got your info from Dryad about longer bows always out shooting shorter bows. But i think you may have misinterpreted that info.... First of all there are advantages and disadvantages to longer and shorter length bows..... your example of a 62" vs a 68" bow is a good comparison..... But.... the draw weight and draw length of the bow is a huge factor in determining hand shock and smoothness between the two.

With a 68" long bow with a narrow profile and a deep core thickness. These bows have excellent potential for high performance and low hand shock if you can get enough tension on the string at brace height to stop the limbs clean. this is where the reflex in the limb before stringing the bow comes into play for lowqer poundage bows especially.

You can take a Hill style straight limb bow that strings up in a perfect "D" shape at 70 pounds At 28" and have a real nice stable limb that shoots excellent at a about 63@26"  draw...... But once you drop the draw weight down to 50@28" you loose your pre load tension at brace and the string isn't tight enough to stop the mass weight of the limbs clean....

Rob gave a good example of the Sparrow Hawk bow advantage of narrowing up the limb and removing a huge amount of limb mass that needs to be stopped in order to transfer the energy to the shaft....

There are many other ways to make a longer bow or a shorter bow draw smooth with good limb stability, by manipulating the working portion of the limb. If you go too far towards the tips, you get a "Whip tip" bow going on that doesn't store enough energy throughout the whole limb.... if you go the other direction and the limb is bending hard at the fades, you are storing more energy, but you have too much mass weight of the outer limb moving forward and it requires a lot of draw weight & preload at brace to stop the limbs clean....

the perfect combo on  "D" shape bow is having  the energy stored evenly in the full length of the limb with the limbs mass weight balanced properly to the draw weight..... this is the part that often gets over looked. as we drop our draw weight down the over all width and depth thickness needs to be reduced proportionately to the draw weight to maintain equal performance.

The problem is... if you have a good design that has a 1.25" to 1/2" width profile at 60 lbs... you can not reduce the profile by a third going down to 40 pounds without loosing your stability.
So you end up with too much mass weight in the outer limb that can't be stopped clean.

The answer to this problem is going with a shorter bow that stores more energy with less mass weight in the limbs, or... using more reflex in the limb using less material to increase the preload.

Hopefully i didn't get too long winded on this for you guys... It's a favorite subject of mine.

Kirk

[Moots]

Very interesting information Kirk.

Thanks!

I have reduced a couple of Hill style bows that I glued up to funny smelling campfire sticks experimenting on seeing how much I could get by with. My 60@27" 68" yew/bamboo is what I would say is the perfect Hill style bow, slightly narrower at the tip than some and slightly faster taper to the lams than some. The result being a bow that has the hand shock timed to my draw length, so that it has very very little and still shoots a very fast arrow while maintaining more forgiveness than most Hill style bows, at least at my 26.75" right hand Hill form. The dynamics of an R/D bow are different than a Hill style to a degree and there may some differences in the limb loading and the release of that loading that I cannot quite picture in my head. As an example, I traded a Pete George for a 64" Robertson, I know tell me I am nuts for doing that, the Robertson has more bend in last third of the limb than some others that I have seen. It shoots really good for me, but I am tempted, perhaps wrongly, to see what I can get out of it with a slightly reduced draw weight. It is fairly straight on the sides of the limbs, I am tempted to trap the limbs. What I am not decided on, what would the effects of a reverse trap be? Where on the limb should the reverse trap be focused to have the effect that would work best for my 26" left hand draw?

[Ralphie]

The second new, Fred Anderson Rover
45#@28, 68"
(and ..........when I asked Fred about fast flight strings, he said not to put them on his bows.)
Limbs; Cherry-wood back, pre-stressed yew belly, maple-wood center, bias carbon core, pink ivory-wood overlays, Riser: figured hard maple,(sugar maple)    
 
   
 
 

Love this bow!

[Brianlocal3]

Very very nice

[dnovo]

Nice bow Ralph.  I'll have to get pics of my Skookum and Timberline up here.

[Ralphie]

When you do Dan, see if you can get a view, unstrung, of the Skookum. I would like to see the difference in the profile. The Rover is reflex/deflex/reflex or "duo-flex", as Anderson calls it. I wonder the difference in the Skookum.
Here are pictures of your Timberline.
It's really a looker !

 
 
 
 

[Ralphie]

Timberline unstrung

[Josh Perdue]

ttt, this thread is cool

[bornagainbowhunter]

My all time favorites are Mild R/D Robertsons.  I just added a Purist to the list.  Rob, its the Robertson Purist you looked over at Solana '13.

I have only had it for a short while, but its becoming my favorite very quickly.

God Bless,
Nathan

My two Robertson twins 'Lefty' and 'Righty' are getting very restless for spring turkey hunting.  I should get a 3d turkey target, so the anti folks can tell everyone how I am torturing a toy turkey and a toy deer.

[Steelhead]

This has been a great thread really.

My 1st custom bow many moons ago was a mild R&D that was beautiful and shot great made by Frederick Longbows.Called a Regeant

I have owned many since then and really like this style of bow.

I saw a few lucky members above were fortunate enough to get some Fred Anderson longbows.One is for sale in the classifieds.If your a true longbow afficianado and want a collector piece and of heirloom quality take a look at it.You wont see many and its a 2012 bow.Fred is 75 years old and contributed alot to traditional archery for half a Century or more.

I bought 2 as well.Fred had a few for sale which is rare.Thier mild bows with graceful lines and they exhibit the perfectionism of a man who has built bows for 50 years.

Ones a Skookem Special that I liked and admired so much that I bought one of the remaining bows he had thats called a Rover.Its a wonderful shooter and elegant looking.The Skookum special is over the top and a real jawdropper.

I will try and post some pice someday.

[Shinken]

This has been a most-excellent thread and brings back many memories!

It was the mild R/D longbow that gave me longbow fever back in the mid '80s and I made the transition from shooting recurves to longbows.  I clearly remember my first longbow - on a college students budget - it was a RAGHORN by Byron Schurg.  Nothing fancy, brown glass over maple with a leather wrapped myrtle handle, but it drew smooth and shot good.  I spent time on the range (5 Valleys Archery Club) shooting with Byron and Monty Moravec - trying out the different longbows that people were shooting - Robertson Stykbows and Howard Hills were common.

Over the years I have owned a number of R/D longbows with my favorites being built by Byron Schurg (Aspen Elites) and Dick Robertson (Purists), but other archers are now enjoying those longbows.

I have one Mohawk in my present herd - built by Vince - that I have really enjoyed as I went through some shoulder rehab and one day I hope to try a Mohawk Sparrowhawk.

The mild R/D longbow will live on - they are just great bows to shoot!

Keep the wind in your face!

Shoot straight, Shinken

 

[TJK68]

I love my Mohawks!!!!! Great thread.
Tom

[Hermon]

Here is my latest bow, Wild Horse Creek "Quest"

62" 53# 28"