Should I increase the number of strands to reduce vibration

backinblack

Active member
But in your particular case, 18 strands of 8125 is well within the range recommended by the manufacturer and, in fact, is exactly what BCY recommend for 8125G.

BCY Fibers
 

Mufti

Member
I would wager a simple adjustment on the limb bolts (the tiller) will vastly improve the bow vibrations.

Make a note of their current positions and adjust away.
Generally a bigger gap at the top when compared with the bottom is required (look up how to measure tiller).

VERY IMPORTANT NOTE: Unwinding the limb bolts too far will have disastrous effects (look up manufacturers guide lines).

Be guided by someone who knows what to do.
 

carl7

New member
I would wager a simple adjustment on the limb bolts (the tiller) will vastly improve the bow vibrations.

Make a note of their current positions and adjust away.
Generally a bigger gap at the top when compared with the bottom is required (look up how to measure tiller).

VERY IMPORTANT NOTE: Unwinding the limb bolts too far will have disastrous effects (look up manufacturers guide lines).

Be guided by someone who knows what to do.
Haha! how true. I took my tiller bolts all the out and measured the thread portion so I'll know exactly how much thread is in the riser at all times.

Carl
 

albatross

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I would wager a simple adjustment on the limb bolts (the tiller) will vastly improve the bow vibrations.

Make a note of their current positions and adjust away.
Generally a bigger gap at the top when compared with the bottom is required (look up how to measure tiller).

VERY IMPORTANT NOTE: Unwinding the limb bolts too far will have disastrous effects (look up manufacturers guide lines).

Be guided by someone who knows what to do.
I have removed the tiller bolts, incidentally they are the 'new floating head' type from Hoyt, to refit the plastic washers that keep coming off. Like carl7 I wanted to know how long the threaded section is. Maximum out turns from bottom = 6 (Hoyt manual). I will try your suggestion and increase the tiller to a 'silly' amount, perhaps 10mm, just to see if there is a difference. If there is then I will gradually reduce the tiller until the problem returns, then back-off from there. I wont worry about the nocking point until I reach some conclusion about the noise, then reposition if needed.

Dennis
 

Mufti

Member
I tend to fix one bolt at its "middle" position (lets say the bottom one) and then adjust the top bolt up and down between -5mm difference and +5mm difference.

A positive number generally produces results.
 

albatross

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I would wager a simple adjustment on the limb bolts (the tiller) will vastly improve the bow vibrations.
Well you would have won your wager last night!

I set the tiller to '0' as advised by Hoyt in their riser manual. I set the top tiller bolt to the 'mid range'. I shot some arrows to warm up.

Shot 6 Bow sounded crappy.
Turn bottom tiller bolt in 1/4 turn - Shot 6 Bow still sounded crappy.
Went through this sequence several more times and suddenly the bow went quiet! Just the sound of the string 'Doink', Even the archer next to me, who previously had commented about 'something loose on your bow', noticed the difference.
Tightened the tiller bolt another 1/4 turn - Shot 6 Bow still sounded crappy again! So I wound it back out 1/4 turn, back to 'Doink' sound.

I measured the tiller - it was 4mm - but I measured it at 4mm previously! Why has it changed the performance of the bow at apparently the same tiller measurement? I do take measurements accurately. Could a 1/4 turn of a tiller bolt, whilst not making a visible difference to the measurement on a bow square, make that much difference to performance?

The down side is that my groups 'went to hell'. Even playing with the brace with the limited time I had left (heavy rain curtailed any more shooting) did not improve things. Probably because now my tuning on the 'Beiter' long rod is now out, and will have to be redone along with more bracing height/nocking position testing.

However. I am more than pleased with the results thanks to the help I have received from you all, it is REALLY appreciated.

This forum is, I can honestly say, the only place that mentions that bow noise can be attributed to tiller adjustment, it is not mentioned in the Hoyt manual.

Dennis
 

Mufti

Member
1) Yes the slightest change in bolt length can have a huge effect at the limb tips ( as you have clearly found out) that may not be measurable at the root of the limb where it interfaces with the bow.

2) You now start playing with the bracing height (according to the manufacturers recommendations). Adjust it in and out with string twists across the whole range of bracing height.

YOU ARE LOOKING FOR A GOOD GROUP!

The sound of the bow may have to be sacrificed in favour of the group..
If you are very lucky you can get groups and a quiet bow.

I have found that the brace height is only a guide and you may end up smaller or larger than manufacturers recommendations.
 

albatross

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1)The sound of the bow may have to be sacrificed in favour of the group..
If you are very lucky you can get groups and a quiet bow.
The strange thing is. I measured a couple of different archers bow tiller last night, just to do a comparison. None were the same and one (the archer who commented on my noise change) actually had a negative tiller. In every case (4) they said they had not altered anything since they purchased their bows! In fact one was very interested to see what I was doing and why! All their bows had previously been quieter than mine. So I am beginning to think it may be the combination of Kaya K3 limbs with my Hoyt GMX riser!

Dennis
 

albatross

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Have you tried limb savers?
Hello.

Yes I did without much success as they had to be mounted nearer the limb pockets which as it now transpires was away from the problem (limb tips). I could possibly have got smaller ones to fit nearer the tip's but that would only add 'another thing' to my setup (although they would probably have slowed the limb speed and maybe cured the problem). But I am happy with the way in which I managed, with help from fellow members, to solve the problem and learned a great deal about limb speed/vibration as well.

Dennis
 
D

Deleted member 7654

Guest
Noise and vibration is the price you pay for modermn bows tuned for maximum speed/flat trajectory rather than maximum efficiency or energy transfer.
As someone pointed out earlier a heavier arrow will do the trick as more energy is in the arrow and less left rattling around in the bow. More strands in the string gives a slight benefit of increased mass with none of the advantages of an arrow with more energy.
The same effect is noticeable even with a self bow, too light an arrow will cause kick or ringing of the bow/string, just increasing the arrow weight a tad and it becomes smooth as silk.
Del
(Sorry, just couldn't keep off this thread... I tried for ages.. honest... but I had to peek to see what you were all talking about. :)
 

albatross

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The same effect is noticeable even with a self bow, too light an arrow will cause kick or ringing of the bow/string, just increasing the arrow weight a tad and it becomes smooth as silk.
Del
(Sorry, just couldn't keep off this thread... I tried for ages.. honest... but I had to peek to see what you were all talking about. :)
Excuses. Excuses. I'm glad you could not resist otherwise we would have been deprived of your input!

Dennis
 
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