Another noisy bow - please help

Emmadragon

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So, I've been shooting for a while now with a Core Air Riser, and SF premium limbs, 20lb @ 68", wound up to 25lb using the bolts on the riser, and the set-up has been very quiet.
I've now changed to WNS Premium limbs, 26lb @ 68", with a new string, and it makes an unbelievable amount of noise when I loose. Not a nice quiet thrummm, but more of an incredibly loud TWANG.
Nothing else in the set-up has changed, and everything is screwed on as tight as it possibly can be.
In order to get the limbs to actually pull 26lb on the finger, (I'm just not strong enough for any more than that yet) I have had to loosen the riser bolts quite considerably from where they were with the SF limbs, and it occurs to me, as I type this, that this could be the source of all the noise. I'll hopefully be going down to a quiet range over the weekend to do all the usual talcum powder on the limbs business, and my ultimate aim is to gradually tighten the bolts back up again to slowly increase the poundage, but what else should I look out for?
Please help! The arrows are still going where they're meant to, like bullets at 20 yards into the gold, but I don't know enough yet about bow tuning to know what else I should look at. I think that the noise 'shouldn't' matter if the arrows are going correctly, but I really don't want the whole line to stop, look at me, and go 'Jesus! That's loud', which happened several times last night. Especially when we go back indoors.
 


Timid Toad

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Same arrows? My guess is they are now too weak and the noise is them striking your riser. Have you fletching damage, cracked nocks or marks on the riser, shelf or rest? (That's what the talc is for, not the limbs) What is your centre-shot like and how stiff is your button?
 


Emmadragon

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Ooh, I didn't think of that. I hope not, they're brand new and were expensive. They are in absolutely immaculate condition, but I have noticed that there is a rubbery residue on the shelf. I didn't know what it was, and cleaned it off a fortnight ago, but now it's back, so maybe that's it. It is right where the vanes could conceivably be hitting the shelf. I guess I'll try the talc on there at the weekend. I'm not sure what a centre-shot is, and how do I measure my button stiffness?
 


Timid Toad

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Ooh, I didn't think of that. I hope not, they're brand new and were expensive. They are in absolutely immaculate condition, but I have noticed that there is a rubbery residue on the shelf. I didn't know what it was, and cleaned it off a fortnight ago, but now it's back, so maybe that's it. It is right where the vanes could conceivably be hitting the shelf. I guess I'll try the talc on there at the weekend. I'm not sure what a centre-shot is, and how do I measure my button stiffness?
Button stiffness - squish it! If your arrows are now on the weak side with your higher poundage, faster limbs you *may* be able to compensate for that by stiffening the button a little. However, it certainly does sound like you have contact with your fletchings and the bow and you really need to look at your nocking point position and tune. Maybe someone in the club can help?
 


Emmadragon

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Aslan, you're a star, thank you. I'll let you know how I get on with that. I really don't want to have to replace the new arrows!
I know that it's a very long list of things it could be, any more suggestions?
 


Emmadragon

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I guess a quick test would be to make the button stiffer and see what happens...
Since I now belong to 2 clubs, I reckon I can find someone willing to help me. Probably at the second club; they run a coaching night every week where one can ask any questions and work on stuff with help.
 


geoffretired

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Rubbery residue on the shelf sounds like the bottom fletch is rubbing the shelf. Could be the nocking point is lower than ideal.
Just a thought, when you changed limbs did you use the same string? If you did, there is a chance that the bracing height isn't ideal for the new limbs and also the nocking point may be different as a result of the change.
I would raise the nocking point a mm or two and see what happens. I would also check bracing height to see if it is as it should be. Also check the tiller of the bow. Test with old limbs , then again with new ones.( if you kept the old ones)
Just a note; that changing limbs for same length doesn't always mean the bow will respond as it did with the old ones. The differences can go undetected when put side by side, but the bow can register its disapproval.
 


Emmadragon

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Hi Geoff, yes, it is a new string as well, and I did re-set the nocking point, which had worked it's way down the old string. I'll be cleaning the shelf off tonight and annointing it with something before I try shooting again. I am also going to try shooting the bow with the old string, just to rule out string noise. I'm pretty sure it can't be just the string making all that noise, but I suppose it might be conceivable. And I certainly don't want to wear my lower fletches away on the shelf!
I always knew there'd be some changes with new limbs and string, I just didn't realise excessive noise would be one of them! Oh well, it'll teach me a lot about tuning as I try to figure out what it is, I guess, and that's never a bad thing.
 


geoffretired

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Ahhh a new string. What I want to say about changing limbs is really that it isn't as straight forward as; take off the old and put on the new. The new limbs may be different in ways that are not just draw weight.
One pair of limbs can match each other very closely, so they would fit on upside down and make little or no difference. Another set can have one of them a pound heavier, and putting them in upside down will change things very obviously. Each set will need its own nock point height and its own brace height. Did you find the nock point height by setting it to the same as the old limbs or by bareshaft shooting to get results from that?
Brace height is another aspect that can vary with new limbs. What sounds good for one set can sound loud on another; even with same riser and same string.
I would say that the noises you are hearing are not so surprising. I have heard lots of people saying that their bow sounds terrible. When asked what they have changed, it is often just the string or the arrows. Those changes can often be all it takes to create the noise. Apart from changing the limbs you have changed the holding weight. That can sometimes change your shooting, a little. You may have a less relaxed loose, for example. That is just an example and not me being unkind about your shooting.
The new limbs need to find their " sweet spots".... or, put another way, you have to allow them the chance to show you what they want.
 


Emmadragon

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I got the nock height with the new limbs and the new string together; it seemed ok, but I reserve the right to adjust it! It's good to know the noises aren't unusual, and I totally agree that my shooting is now less relaxed, no offence taken. The 25# had got very easy, but the 26# is more of a strain right now, until I get used to it.
I'll be experimenting a bit tonight, it's a shooting night for me. I shall report back. :poulies:
 


Emmadragon

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Well, I can report that the bow is a little quieter now. I adjusted the stiffness of the button very slightly, to make it a tiny bit stiffer. The fletchings now don't wipe across the shelf at all. Nothing seems to be hitting anything else (did a powder test), and the arrows are certainly going where they should. I think the residual noise is because the limbs are comparatively 'loose' in their pockets - that's because I had to wind the bolts out a bit to get the poundage where I wanted it; I hasten to add that my coach checked it and agreed that they weren't unsafely loose. As I get used to the increased poundage, I'll be able to gradually tighten them back up, and that should reduce the remaining noise. The old string, when put on, made almost exactly the same amount of noise as the new one, so it's not the string. Everything else is tightened up to the nth degree, I'm always very careful about that since an incident with my longrod, so the only remaining 'looseness' is in the limb pockets.
Thank you all, so much, for your suggestions, I really appreciate it.
incidentally, shot at 40 yards for the first time last night; not one arrow in the green, and got a 252 when we weren't even trying for it, so I'm thrilled.
 


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