Shorter riser equals what?

[razorsharptokill]

If I deviate from the bingham plans for a take down longbow or recerve by shortening the riser, what effect will it have on draw length and weight given the limbs are left the same length according to the plans?

[Kelly]

Draw weight will increase and draw will not be as smooth.

[kctreeman]

I did that once for a buddy. The bow came out with a little increased draw weight and stil shot real well.

[Bjorn]

The change is very subtle, using the bear takedown as an example, reducing riser length 4 inches changes the pull from 43# to 45#.
Reducing the riser 10 inches produces a 6# increase in pull strength.
Whereas if you shortened the bow by shortening the limbs by 4 inches you would gain about 10#.

[SOS]

I shortened my Pronounced longbow one inch in the riser and  1 1/2 for both limbs for a 64" bow.  A very short riser like the one I had on my 56" Chekmate Hunter I made for a short window and I had to shot it three under.  Guess it depends on how short.

[rg176bnc]

I would think it would give you a longer working limb.  Smoother draw?  Im no bow builder though.

[Mike Mecredy]

On a three piece take down it raises the draw weight, and lowers draw the length. On a one piece it lowers the draw wieght (as long as you used the same lenght limbs)and will alow for a longer draw length, but increased finger pinch.

[sidebuster]

I thought the poundage would decrease if you decrease the length of the riser?  I remember Bingham saying the following:

Note:1  For every 2 inches you shorten the length of bow you increase poundage by 7#s

Note:2  For every inch you shorten the riser you decrease the poundage of bow by 7 #s

Note: 3  For every inch you increase the draw length you increase the poundage by 2.5 or 3  #s

Think about it as your riser got longer and longer the bow would become stiffer and harder to pull back.  Maybe I wrong.  Any one want to confirm this.

[vermonster13]

Shorter riser of the same pad angles = heavier draw weight. Take a look at the Bear limbs and you'll see what I mean, A riser = 56" 50@28, B riser = 60" 48@ 28 for example. On Olympic risers it's about 1# increase for each inch shorter the riser is.

[Mike Orton]

I second what the Vermonster man says.

I presently own an ACS-CX, standard 14 inch aluminum riser and limbs to make a 66" bow. Limbs are marked 67# at 28"  

I have on order a 16 inch riser.  I asked John Havard that very question, "How will the extra 2" longer riser effect draw length"?  John's answer: "Should  lower  draw weight by a few pounds".

For me a 68" longbow provides the best monopod platform to look through my binocs while hunting.  66" Longbow makes me squat down 2 inches to see through binocs.  Humping hills makes my legs burn and I don't need to be squatting 2 inches to look through binocs for a rest.  Hell the binocs are usually the excuse to stop and rest anyway.

 

[sidebuster]

I guess Mike Mecredy clairifes my statement.  I was taliking about a one piece not a take down. On a one piece then if you build one longbow of 64 in with a 17 in riser and then build the same bow with a 16 in riser the poundage would be lower with the 16 in riser.

[Mike Mecredy]

Yes Sidebuster, if you were to take an inch off your riser length you'd be adding a half in of length to each limb, dropping the poundage about 3-5#.  With a once piece longbow.  You'd drop a little less with a recurve, maybe 2-3#.

[vermonster13]

So you are talking about shortening the riser but lengthening the limbs not leaving them the same length as stated above.