Why does my bottom limb always bend back faster than my upper limb when I shoot?

[toomanyknots]

This is killing me, on almost every bow I shoot, when I release the bottom limb bends back about straight before the upper one. You can only see this on video looking frame by frame, or slowing it down, but it's weird. Is this normal? My handle is exactly center of the bow and I shoot maybe an inch above center. I can upload a video to youtube, but you probably wouldn't be able to see it as their scroll bar doesn't really go frame but frame, but sections of frames and would probably skip it. Could I be releasing with my bottom fingers first, and letting the string roll downward? Doesn't seem like it would effect it too much. Could it be because of my form? Pulling up too much? I don't know, it's wierd...I just noticed one day while looking at a video of me shooting this bow to see how I was bending it when I shot it...

[Pat B]

Can you have someone take a few pics of you drawing the bow so we can see the bow bend(at brace, mid draw and full draw) and your form as you draw?
  The bottom limb should be slightly stronger than the top limb to compensate for your hand placement and arrow pass as it relates to you drawing the bow.

[toomanyknots]

Ill just upload a video I just took, ill post the youtube address in a min... If they're the same strength but I still draw an inch above center, then could that be the reason? I have tried moving the handle down a could inches, but for me the arrow always goes so much straighter when up just a bit on a symmetrical bow...

[toomanyknots]

k, heres the link:

http://www.youtube.com/watch?v=nRYJ_0PRxRU

After pausing it, it does appear that I am pulling up a bit. When this happens, I usually just put my arrow up just a bit more making the upper limb stronger and evening out my draw. I do believe this is where my inaccuracies are rooted though... How do you place your handles? I have read on here I think for a 6" hanldle (which is small for me, I use 7") about 2" on the upperlimb and 4" on the bottom limb.

[NTD]

I paused it at 31 seconds.  You can see the tiller pretty decent here.  It looks like your top limb is quite a bit stiffer than the bottom.  Don't know how all this relates to limb return though.  Have you done a bit of kyudo?  Your drawing style reminds me of it.

[Pat B]

When I set up a bow I find the center and make that the center of my 4" handle. I then go out 1 1/2" to 2" for the fades above and below the handle and start the limbs from there. My arrow pass is about 1 1/2" above the center. That is at the top of my hand when I grab the handle.

[George Tsoukalas]

Bottom limb is weaker. I take a few passes with a scraper on the top limb until it evens off. I make my wife take digi pics while I draw. LOL. Jawge

[toomanyknots]

"Bottom limb is weaker. I take a few passes with a scraper on the top limb until it evens off. I make my wife take digi pics while I draw. LOL. Jawge"

Ya, if only MY wife could take good pictures, If does this on every single bow though. I think I finally am starting to get why the bottom limb should be stronger...

"paused it at 31 seconds.  You can see the tiller pretty decent here.  It looks like your top limb is quite a bit stiffer than the bottom."

I think I just pull up when I draw, I don't know why. Probably because it is easier to draw heavier bows for me that way. Yes it does look stiff, but the problem is it looks absolutely perfect on the tiller tree up to 28". So wth yalls help I am led to suspect that the cause lies with my draw... In a minute I will post a vid where you can see the tiller much better...

"Have you done a bit of kyudo?  Your drawing style reminds me of it."

Ha, no, but this makes my day. Wish I could take some. I have seen alot of videos of kyudo and there is so much ceremony involved I think I would loose my mind just trying keep myself from saying screw it and just shoot. I see em walk all slow motion to the shooting places and I'm like" man, can they at least walk normal speed? lol

"When I set up a bow I find the center and make that the center of my 4" handle. I then go out 1 1/2" to 2" for the fades above and below the handle and start the limbs from there. My arrow pass is about 1 1/2" above the center. That is at the top of my hand when I grab the handle. "

Thank you pat, this helps alot.

[Pat B]

As you are drawing your bow you should be able to feel if the top and bottom limbs are putting the same pressure on your drawing hand. Raising or lowering the arrow nock on your string will also change the tension top to bottom.
   Your tiller tree gives a static look at tiller. Your hand compensates for changes so it will not necessarily be the same full draw picture as when done on the tiller tree. This is why a pic of you drawing the bow and a full draw pic will help us and you see whatever problems you may have and can help with the solution.

[toomanyknots]

My camera is horrible and won't take a pic that isn't blurry, at least without alot of skill and patience. Wife can't do it. I don't have anyone to do it right now, but she'll take a vid? I think the tiller is easier to see in this one:

"http://www.youtube.com/watch?v=4tRlwobdcJ4"

If I find someone lurking around willing to take a pic a couple times though, I will get one up pat. Never ever pay anything less than 50$ for a camera again.

"As you are drawing your bow you should be able to feel if the top and bottom limbs are putting the same pressure on your drawing hand."

Ya, I know what you mean. This is insanely annoying to me when I draw with the arrow just a tad bit up and can feel the arrow going up, and have to compensate by aiming up a bit instead of down. I hope I can get rid of these things by making a bow with the handle adjusted to how I draw, or learn how to draw evenly.

EDIT: Ok, finally grasping the obvious, I see my arm is WAY higher than is should be for proper form. lol

[aznboi3644]

I'm not sure what camera you have...but I've seen this phenomenon on videos of my subwoofers moving a lot....makes then wobble.

Some cameras dont record the whole image as one...kind of like a top and bottom separate then played together...messes with the timing a bit.

Just my opinion.

[Del the cat]

Your tiller tree may be giving a false picture.
Is the bow free to rock on the tiller? Do you support the bow near where your hand takes the pressure? Do you hook onto the string where your fingers pull the string?
If you set the bow up on the tiller like that, it can sit really weirdly a low draws because both support point and pull on the string are way off centre and the bow may tilt wildly towards the top limb, this is most noticeable on short bows.
It may look odd but it's what is actually happening (or trying to happen) in use. Of course your firmer grip and the positioning of the bow at the start of the draw mask this effect.
I've never once actually heard a valid convincing reason why the lower limb should be 'stronger' than the upper one, and yet everyone (except me) quotes it .
I can give an argument for the reverse... if the lower limb is to have the same deflection as the upper and yet it's shorter it must bend through a tighter radius and therefore it must be weaker as it's bending more for the same applied force.
Of course I may well be wrong, I was certainly wrong to be sceptical about heat treatment and my wife informs me I'm wrong on a regular basis .
Del

[DCM4]

I've never once actually heard a valid convincing reason why the lower limb should be 'stronger' than the upper one, and yet everyone (except me) quotes it .
I can give an argument for the reverse... if the lower limb is to have the same deflection as the upper and yet it's shorter it must bend through a tighter radius and therefore it must be weaker as it's bending more for the same applied force.

You gave the perfect reason, just in reverse of the reality.  By that I mean, when you fold together a string at the nock point, which is the longer segment?  Fact is the geometry doesn't know how much of the lower limb is handle, ie. non-bending.  Rather it only is influenced by the distance from where the arrow is nocked on the string... and obviously the angles struck by the upper and lower segments.  When you get done string folding experiment you'll see the lower limb always enjoys a much better string angle.  From a bowyer's pov, the lower segment is like a long bow with no stack, the upper the reverse.  Positive tiller is to make the lower limb start with more draw weight, relative to the upper, because the upper is gonna stack like a muther (due to it's being shorter) and they need to be the same at full draw or you'll have bow rotation (upper limb toward archer).

What is a trip is when you study the return, or power stroke.  In this scenario the inherent asymetry between the upper and lower segments, and relative spring rates, means the arrow nock moves (up and down) along the lenght of travel.

[Del the cat]

Thanks DCM that makes sense and is a great help, but it's hard to tell if it's the full picture or do the two effects cancel out.
I actually think the expression stronger or weaker is a missnomer, because it depends how you measure it  (eg poundage per unit deflection divided by limb length or what? Surely it's better to simply say the limbs must be balanced when pulled on the tiller somewhere close to a realistic position.
Your line " because the upper is gonna stack like a muther (due to it's being shorter) " may need some explanation or editing as the upper limb is surely generally longer not shorter? ( ok the upper string segment is shorter).
I like your comment about the up/down nock travel on loose, I've tried to look at this on the tiller (which isn't quite the same of course) and I'm always careful to watch for changes of handle angle as the bow is drawn on the tiller (does it rock from side to side).
I think this is a subject requiring more critical thought as I must effect a lot of short bows and be particularly infuriating for those who find a bow which appears fine on the tiller looks out of tru in the hand.
But on the other hand sometimes the analysis just gets in the way of looking at it and making it look right.
Cheers

Oh and back to the original question in the thread, if the lower limb returns too fast surely it needs weakening, the suggestions to weaken the upper limb will surely do the oppsite? Maybe just tie an anvil to the lower limb? That'll slow it a tad .!
Del

[DCM4]

The bottom limb is longer if you look at it from the perpective of the arrow pass, or the string nock.  It's just easier to fold a string in half than a bow.  ;-)  Again, the geometry doesn't care about whether part of the lower limb doesn't bend (ie. it's really the handle).

I didn't look at the video but everybody said it looked like the lower was bending generously.  Shortening it will have the effect of offsetting some of the asymetry (versus the upper) requiring less positive tiller, and stiffening it.  Two birds with one stone.