Arrow flight tail up.

[Bud B.]

Hey guys and gals, need a little help.

I have a 66" #40 RD longbow that is throwing GT 15/35s with 125 up front and full length shaft pretty good but arrow flight indicates nock high. I draw 29". Total arrow weight is 394-401 range. I get a tipping of the tail of the arrow as it flies down range. I move the nock up and down but am still seeing it. Could raising the brace height fix this? The tail of the arrow raises about 4" before leveling out and hitting the target. This rise in the fletching seems to want to throw the arrow downward a bit too. Left/right flight is good.

Brace height is at 8.25 curently with nock fit good and serving is in good shape. B55 10 strand flemish. I drew it back to about 30" or more just trying things out and flight seemed to level off better. This makes me think I need to raise brace height.

Any help is appreciated.

[mooseman76]

Are you canting the bow?  If so, are you canting alot?  I ask because you may be seeing tail left that shows up as high if you are canting a bunch.  If you are canting try shooting the bow vertical and see if your results are the same.

If this isn't the problem it sounds like you are getting contact with something.  Maybe the fletching is bouncing off the shelf???  Could be caused by the alignment of your nock or you could even be exerting downward pressure on the arrow that makes it contact the shelf.  

One last thing, you certainly can try adjusting the brace height.  I can't think of why that would be causing your flight problems, but it is quick and easy to try.  Good luck and keep us posted...Mike

[Bud B.]

I cant the bow but the tail up is in line with the bow's top limb. It happens in line with the top limb whether straight up or canted. I aligned the nocks but still had some high tail flight. It seems the higher brace height did some good. The arrow certainly flies faster. I need to go to a double nock point.

I twisted the string so much I made a new string so the twist isn't as much.

I'll try again tomorrow if I can get home before dark.

[Jock Whisky]

Raising the brace height could very well solve your problem. Had the same thing. I was told that arrows have vertical paradox as well as horizontal and if all else fails raising the brace height will probably smooth out the flight. Worked for me

JW

[MD]

My question would be what is the actual draw weight at 29 inches 42+ pounds , what arrow length and tip weight. Might not have enough spine.

[Pepper]

Try rotating your nock about 30 degrees at a time, and watch arrow flight.
Carbons, especially the lighter ones show effects of spine more than the heavier ones.
The 15/35's may not be stiff enough.
Try reducing point weight, or get a couple of 35/55's and give them a try.

[bigbadjon]

I doubt raising the brace height would change anything, if it levels off at a higher draw ei speed, raising the brace may make it worse. Are you touching the nock when you draw the arrow? Also draw the arrow back and have someone confirm that your arrow is not bent at full draw. It may be you are bending the tail of the arrow toward the ground at full draw.

[Bud B.]

I can't put the bow on a scale.

These are Stu's Calc figures:

 

Keeping in mind arrow weight is 394-401.

I was able to shoot some today with a new string 10 strand B55 flemish without string silencers. The arrows are zipping to the target with minimal tail movement now. What I'm seeing now apears to be paradox. Arrows are hitting nearly every time where I'm looking at 15-20 yards. No broken nocks but lots of arrow slap. I plan on putting yarn silencers on this new string and keep the brace at around 8.5" to see if my shooting is consistent with this setup. I shoot two fingers under and have now went to a double nock point to prevent nock travel on the string upon release.

Thanks for the comments and input.