Archery Talk Forum banner

1 - 20 of 27 Posts

·
Registered
Joined
·
487 Posts
Discussion Starter #1
First off, I know there have been dozens of threads over the last 5 years on this subject, however I think my situation may be slightly different than the norm. I'll summarize first then give details afterward. For discussion note when I say the top of the idler wheel leans to the "left" I mean that the top of wheel is at 11:30 and bottom is at 5:30 when looking at the bow from behind it (from the string). When I say the string comes off the wheel to the left I mean that at full draw if the wheel were at vertical (12 oclock and 6 oclock) the string would look like it is at 6:30 when viewed from behind. Hope that makes sense for discussion purposes.

Now the story... here are some facts for the bow I am trying to tune :

Mathews Drenalin LD (DLD).
37 inch ATA
60# Draw
30.5 inch Draw length
6'5" height (may get input on if the 30.5" DL is correct)
D-Loop
Mechanical Trigger Release
29 inch Carbon Express Blue Streaks 250 (note they are 250 which is another one of my questions)
100 grain points
QAD UltraRest Hunter Dropaway
Shooting with ODD fletching pointing up

I adjusted nock up and down to rid of the vertical tear which was not a problem to accomplish. HOWEVER, the QAD rest needed to be raised in order for it to not smack into the shelf at the shot. Trust me you can tell a difference in the noise just by moving rest up and down a little. It is LOUD when it smacks the shelf. So I had to raise it just slightly. With all that, now the arrow is about 1/8 or maybe a little more than higher than the berber hole. It is strange that the rest was not made to drop without hitting the shelf so the arrow would line up with berber hole. So right now, that is where the rest is set at, and the nock is about 1/8 to 3/16 high of horizontal which is as I understand it a little higher than average but still that works to rid of the vertical tear.

I cannot paper tune this on the left-right for the life of me. ALWAYS a left tear (nock to left of point at entry in other words vanes to the left in tear). This tear can be around 3/4 to 1 inch. So now as I said the left tear is the big issue. I started with the rest at 11/16 from riser as I read is recommended for a dropaway with a Mathews. Still left tear, moved rest right per Easton recommendations and slight improvement but not much. Kept moving rest right, slight improvement. But then eventually got vanes to hit riser so throw the move rest right solution out as a no-go. So just to test, moved rest to the left, when to 12/16 and 13/16 and on and no improvement. Got to the point at about 13/16 that the bottom right vane was hitting the right launcher arm of the rest, so not good. So concluded that moving the rest left and right was no solution.

Ah ha, now to test some bow changes themselves. Got to reading about idler lean on all these forums. So I put straight edge on left side of wheel to see where it intersected my string at nock. Low and behold it is about 3/16 to 1/4 inch to the right of the nock when looking at it from behind the bow (I attached a nice picture to clarify). This would lead me to believe there is too much lean in the wheel so I would need to tighten the left side yoke and loosen the right side yoke to get the straight edge to hit the nock about at center of string (that is another question, where is it supposed to intersect string??).

Lastly, I drew the bow and had someone else look at the lean. The string definitely comes off the idler wheel to the left. Like I said earlier if wheel were vertical, string would come off the bottom at 6:30 or so (another picture attached WHICH IS NOT MY BOW but an illustration from some website of what is occurring).

So here's how it boils down. Seems like at rest, the left side yoke should be tightened and right side should be loosened to get the straight edge intersection to move to the left so it is closer to nock. BUT, the illustration picture I attached that shows at full draw if the string is to the left, then you should loosen the left hand side and tighten the right hand side of yoke, just the opposite.

This is just plain strange that at rest it proves you should shorten left yoke but at full draw you should shorten right yoke. WHICH ONE DO YOU GO BY?

OR, maybe the 250 spine arrows are too weak. Go to 350 spine? On that note, I may lighten to 50# DW and see if paper tune improves since I know for a fact that 250 spine with the Blue Streaks are good for that weight. Like I said, I am pulling 60#
PLEASE PLEASE give your opinion on this as to how to adjust yoke.

2013-09-15 14.05.40 small.jpg 2013-09-15 14.05.27 small.jpg idler lean - shorten right yoke.JPG

Thank you to all,
Greg
 

·
Registered
Joined
·
643 Posts
I think that twisting the right side is gonna make his tear worse.
Check the sticky The Nuts and Bolts of Archery.
 

·
Registered
Joined
·
487 Posts
Discussion Starter #7
WOW, quick responses. thanks all.

I can't believe I have been thinking incorrectly all this time. In general, shortening, or tightenting or "adding twists to" the right side yoke will move the TOP OF THE WHEEL to the right. That will line up string with wheel at full draw. AND, at rest, that will also move the straight edge location at the nock point to the left so the 1/4 gap currently will then be moved towards the center of the string. Does that all make sense?

Embarrassingly, I was thinking shortening of the right yoke would pull BOTTOM of wheel to the left, not right....
 

·
Registered
Joined
·
643 Posts
WOW, quick responses. thanks all.

I can't believe I have been thinking incorrectly all this time. In general, shortening, or tightenting or "adding twists to" the right side yoke will move the TOP OF THE WHEEL to the right. That will line up string with wheel at full draw. AND, at rest, that will also move the straight edge location at the nock point to the left so the 1/4 gap currently will then be moved towards the center of the string. Does that all make sense?

Embarrassingly, I was thinking shortening of the right yoke would pull BOTTOM of wheel to the left, not right....
Yes this makes sense. I just think that this is gonna make your tear worse.
Try it, you can always go back the other way.
 

·
Socket Man
Joined
·
23,215 Posts
My brother has a drenalin and it is one of the sweetest bows I have ever had the pleasure to assist with in the tuning process and produces awesome arrow flight. To me you are adding problems to the bow by introducing cam lean that may not be needed but that is your choice, I can tune a bow to shoot good with or without cam lean. To me anytime I have a bow that will not respond to moving the rest left or right and it gives the same tear it is because the shooter is introducing grip torque to the bow and the grip problem is so big it swallows everything else.

The spine of your arrow doesn't matter your arrow choice is just fine and will tune but you must address the grip of the bow first, second I would get the bow back to factory spec and at full draw I wouldn't have any cam lean if you have a press to do so. This is where I would start.
 

·
Registered
Joined
·
643 Posts
My brother has a drenalin and it is one of the sweetest bows I have ever had the pleasure to assist with in the tuning process and produces awesome arrow flight. To me you are adding problems to the bow by introducing cam lean that may not be needed but that is your choice, I can tune a bow to shoot good with or without cam lean. To me anytime I have a bow that will not respond to moving the rest left or right and it gives the same tear it is because the shooter is introducing grip torque to the bow and the grip problem is so big it swallows everything else.

The spine of your arrow doesn't matter your arrow choice is just fine and will tune but you must address the grip of the bow first, second I would get the bow back to factory spec and at full draw I wouldn't have any cam lean if you have a press to do so. This is where I would start.
I didn't want to address the possibility of grip torque but I think this is probably the case.
Reason being with the idler wheel leaning to the left at the top that should give a right tear.
Since you have a left tear there's a very good possibility that Padgett is correct.
 

·
Registered
Joined
·
487 Posts
Discussion Starter #11
While at full draw I can look at the idler lean and then "fix it" by torquing the bow to the left (looking down on the bow, torque clockwise), to get the string and wheel to line up, still left tear. When I introduce that "left" torque and put all kinds of grip pressure on a lot of the meat of my thumb the cables get twisted toward the arrow shaft and sometimes the vanes hit the cables....not good, so that tells me that I have to introduce torque to get "better" paper tunes. I have had other advanced shooters shoot it as well and they all get the left tears. But, I agree with left tears, typically the left yoke gets tightened which is why this thread is called counter intuitive in the subject. I will be at the range tonight.

Regarding incorrect DL, I have shortened my release to ensure my index finger wraps the trigger so I am not punching it, but squeezing it instead, and I have had others look down my line and confirmed DL is about right.

Thanks for the great feedback from you experts...:teeth:
 

·
Registered
Joined
·
643 Posts
While at full draw I can look at the idler lean and then "fix it" by torquing the bow to the left (looking down on the bow, torque clockwise), to get the string and wheel to line up, still left tear. When I introduce that "left" torque and put all kinds of grip pressure on a lot of the meat of my thumb the cables get twisted toward the arrow shaft and sometimes the vanes hit the cables....not good, so that tells me that I have to introduce torque to get "better" paper tunes. I have had other advanced shooters shoot it as well and they all get the left tears. But, I agree with left tears, typically the left yoke gets tightened which is why this thread is called counter intuitive in the subject. I will be at the range tonight.

Regarding incorrect DL, I have shortened my release to ensure my index finger wraps the trigger so I am not punching it, but squeezing it instead, and I have had others look down my line and confirmed DL is about right.

Thanks for the great feedback from you experts...:teeth:
If you put a full twist in the left yoke would you be worried that the string would derail?
 

·
Registered
Joined
·
10,363 Posts
doh typo... LEFT sight it is monday lol
i correct myself....it is the right side to pull the limb down to move the bottom ofthe idler to the left because the yoke is stationary. so if you twist up the left side it will make the top lean to the left making it worse. so you want to twist the right side up to put more pressure on that side to pull the top of the idler to the right which will straighten the idler up. mathews recommends the shaft down the left side of the idler on a right handed bow bisect the string at the nocking point as a good place to start. then you may have to make minor adjustments to get you paper tear where you want it
 

·
Registered
Joined
·
487 Posts
Discussion Starter #14
archerdad. Thanks for the recommendation by Mathews regarding where the straight edge should hit the nocking point. As you saw earlier my line is far right of the nocking point, 1/4 inch too much.

when I think about it more, the string is off center to the left compared to the riser when at full draw thus the arrow point would be aiming right and thus the vanes would come off the rest to the left thus the left paper tear. Hard to describe but maybe this is all coming together.....:star:
 

·
Registered
Joined
·
10,363 Posts
archerdad. Thanks for the recommendation by Mathews regarding where the straight edge should hit the nocking point. As you saw earlier my line is far right of the nocking point, 1/4 inch too much.

when I think about it more, the string is off center to the left compared to the riser when at full draw thus the arrow point would be aiming right and thus the vanes would come off the rest to the left thus the left paper tear. Hard to describe but maybe this is all coming together.....:star:
i would start there. then i think the newer mathews recommends a 13/16 centershot and somtimes i have had bows that i just had to start over with....patience and time will get you there...
 

·
Registered
Joined
·
487 Posts
Discussion Starter #16
So just got back from club where I tried some things. First I did tighten the yokes some. Left side 4 twists and right side 8 twists maybe more. Now, the idler wheel straight edge line intersects the nock directly in the middle of the string which seems right. Them I put the rest at 13/16 from riser so arrow interests center shot line on grip. Then shot some arrows. Still left tear, better but still visible 3/4 inch. So then I tried introducing what I thought was hard left and right hand torque. Putting rest pressure right up my lifeline produced crazy tear. Then tried introducing torque to the left side, that is, put more of the meat of my thumb towards my thumb on grip and somewhat wrapped fingers around front and guess what, 8 bullet holes in a row. I do think I am putting more twist than is the proper way into the grip but seems to work obviously. So with all that I also have another question. The ata measurement is 37 3/8 whereas it should be 37 and therefore the brace height is 6 3/4 whereas specs call for 7. I suppose having the ata slightly long is ok. Any reason to twist up some strings to get back to 37. Even if the answer is not to worry how would one decrease ata? Seems like twisting the yokes you'd have to twist about 20 times to get that 3/8 inch reduce out. Can you twist the yokes together right at the Y intense tips where yet come up out of the serving just up from the roller. There was 3 twists in there like that but some guy who seemed like knew it all was set on removing those twists for some odd reason so we did rid of them. However untwisting those added 3/8 to draw ata. Thanks again.
 

·
Registered
Joined
·
487 Posts
Discussion Starter #17
Typos.....sorry

....to increase ATA, Can you twist the yokes together right at the Y intersection the string comes up out of the serving just up from the roller guard. There was 3 twists in there like that but some......
 

·
Socket Man
Joined
·
23,215 Posts
Sounds like at the club you made some changes to the strings and got the bow closer to a neutral setting which allowed you to get some bullet holes by griping the bow differently. To me you had in the days before a bow that was way out of wack and your grip added to the problem and last night when you got the bow back to normal then the slightly different grip gave you bullet holes. I would love to see you at full draw with your normal grip to see what it looks like, I would also suggest looking at levi morgan and reo wild pictures on youtube and look at their grips on the bow.
 

·
Socket Man
Joined
·
23,215 Posts
I have a way to train yourself to a new grip that has many benefits in the long run, take a piece of mig welding wire or a wd 40 red straw and duck tape it to your riser on the side closest to you at the height of your lower sight mounting bolt. It should stick out about 1.5 cm into your window and when you draw your bow back and come to anchor the red straw will be seen in your peep, move it in and out until it lines up with something in your sight housing such as the black lines on the bubble level or on my single pin vertical pin I line it up with the vertical pin. Now you can tell if your grip torque is the same every time you draw the bow which allows you to change a grip and have something that keeps you honest.
 
1 - 20 of 27 Posts
Top