Ugly twang on R/D Recurve self bows...

[TimmyDeNorCal]

I’ve built a few reflex deflex recurves lately...and they turned out fairly nice...

...but I absolutely detest the ugly twang I get at the end of shots and even on string plucks!!

Each bow has about 3-4.5” of string contact starting at the tip overlays (obviously) and then down the limb tip. Oddly enough, I don’t notice this ugly, personally-deflating sound on my normal self bow recurves. Instead, I receive the solid, satisfying sound of a tight, well-tensioned string - when just plucking at brace or after the shot.

I tried increasing brace height, it slightly diminished the ugly twang, likely from less string/limb contact, I imagine...but it did not remove the sound...and I will not increase the brace height beyond 6.5” or so on my self bows.

I guess my question is, is there a solution? Do other people experience this problem, as well?

The other fix I attempted - on 1 of these bows - is to install small string bridges. I fashioned 2 small contoured string bridges from some walnut I had laying around...but the sound was still there, and it might even be worse now as the string slams back into the slightly raised walnut wood!!

Should I try string bridges of hardened leather (by using contact cement or something??)?

Hoping for a solution, because I love the design of these bows...but I hate the way they sound after the arrow is released.

Lastly, I haven’t tried string grooves yet. Mostly because the outer limb tips are more rounded in cross-section (unlike in my recurves where I keep them flatter for a longer percentage of limb. Those receive string grooves easily).

[Selfbowman]

Easiest to help is strips of fur. About 9-10” from loops .

[superdav95]

I use string bridges with a small section of leather on it’s Face to take up the twang sound. Works for me. 

[TimmyDeNorCal]

Those were the 2 possible solutions I was thinking of, and hadn’t tried.

It’s nice to hear to from others who have already remedied it.

Thanks, fellers, I’ll give ‘em a try.

[bassman211]

Install  a set of ear plugs on the string were the string makes last contact with the limb. Adjust them as you shoot the bow, and lock them down with a drop of glue. Easy to install with a bobby pin, and cheap, and best of all it works.

[bradsmith2010]

then put ear plugs in your ears problem solved

[Eric Krewson]

I get a lot of "twang" when I use D-97 for strings, not so much with B-55, I prefer D-97 so I add silencers.

[Selfbowman]

I get a lot of "twang" when I use D-97 for strings, not so much with B-55, I prefer D-97 so I add silencers.

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Eric I argued with Rick Barby about B50 string noise vs D97 . I swore B50 was more quiet . He finally got a  decimal meter. I was wrong. The B50 just has a lower tone.

[Badger]

How much set did the bow take from it's original shape? I have found if a bow has taken too much set it twangs..

[TimmyDeNorCal]

Oooo, the ear plug idea sounds like another good idea!

My latest attempt has seen me slightly raise the brace height - to about 6.375” or so - and I have added fur string silencers. The twang has dropped considerably, so much so that it is much more manageable.

Badger, as for set, the bow has registered about 1/2” to 5/8”. It is one of my lower set bows. I would post pix, but, shamefully so, I have yet to figure that out yet. I have tried all of the tutorials and everything, done it on a computer and not a phone, etc., & I just cannot seem to do it. Ridiculous, but sadly true.

We’re you thinking it might be a set issue? I go crazy slow with my tillering and have managed very low set over my past 5 or 6 bows. One of the things that helped me was that I was too caught up in the stuff out limb idea...and I think I wasn’t allowing for enough bend there. And so my bow limbs took more set than they should have in the outer limb, being that they were thicker there then they should have been.

[TimmyDeNorCal]

Badger,

It’s as if I just have too much unaccounted for string contact, and the twang is bothersome, and just annoying.

On a normal static recurve I would have accounted for the string contact, of course...and I guess by its very design I would have kept the outer limb tips wider, and flatter. Then, if need be - which I guess I always feel the need - I’d have filed in string grooves. And, even though the finished bow features a lot of limb contact with the string, there is only that satisfying decently high-pitched tone from a string pluck.

But in the R/D bow, if the reflex in the outer limbs is great enough, the bow is more of a man RD Recurve in design (I think I will design my next few RDs with a more gradual, elongated sweep in the outer limbs thereby rendering it a dern RD ONLY!). But, for now, these RD recurves sound terrible...even with a (shamefully slow!) tiller that ended up with decently low set. 

The reason for my post was to see if other people had run into this issue, and if so, how they dealt with it. I’ve received some good tips so far...but I think my next question would be whether I should design the outer limbs and tips like I would a regular static recurve - meaning wider, flatter-bellied, with string grooves. OR, should I just forego the recurve effect on the tips of any & all RD-limbed bows...?

To make this post even longer, I will just add that I got into this situation because I was hoping the outer limbs would not create string contact down the limb...but then I heated in bends that created them, while not accounting for them when roughing out the limbs.

[paulsemp]

I've had a few that have d flex in them where there's not a lot of tension at brace. Raising the brace height can help tremendously. The only thing that makes sense to me is there's not enough tension at brace to stop the string vibration. I posted a few months back a yew deflex static I made. Anything under 6 and 1/2 in brace it was not shootable. Get it up to 7 in and it was like magic

[IdahoMatt]

What type of string do material are you using.  Also sometimes if you twist the string too much it will get more stretchy.  I use d97 and try not to get too much twist into them.  Just enough to get them together.