# 27" Riser Benefits?



## x1440 (Jan 5, 2003)

My draw length is 29.5-30" and I'm currently shooting a 68" bow, 25" riser with Med limbs.

I'm planning on upgraded my bow and was wondering if it would be better for me to get a 27" riser with short limbs or upgrade to a 70" bow with a 27" riser and Med limbs.

Is there any benefit to a 27" riser at my draw length?


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## Mika Savola (Sep 2, 2008)

27" riser with short limbs may stack even more


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## Flehrad (Oct 27, 2009)

You should be using a 70" riser for sure.

The slight advantage of going to a 27" riser with medium limbs (as opposed to 25" with long) is the limb length is shorter, which means for the same shooting weight at full draw, the limbs will act snappier. You have to be careful with your calculations in what limb weight to get though since most limbs aren't given in specs relative to the 27" riser.

I only have a 28" draw and I use the 27" and short limbs for the 68" bow length and find it to be quite good.


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## Borderbows (Apr 4, 2009)

it will stack quicker if the limb pad angles are equal...

For example, a bow wound in will stack quicker too, so a 25" wound in will stack similar to wound out on a 27" for the same weight on your fingers.

The problem with winding limbs out is that they in turn are a little slower... so slower due to less preload meaning less stored energy vs less limb mass = the possability of the same speed...

If i were you i would go 70" bow if you want smoothness... then choose from there if you want a 70" for a 25" riser or 27"...


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## Flehrad (Oct 27, 2009)

People talk about 'stacking' all the time, but until you actually try the bow, you really have no good idea of the physical manifestation of the concept. I feel no stacking at all with my 27" riser and short limbs compared to my 25" riser and medium limbs. I'm lucky in that my draw length is pretty much 28", so I am not pushing the boundaries of the draw ranges, but if you look at the draw force curves measured by various people, the force differences can be quite small, and I believe that one particular Hoyt engineer was spot on in saying that, it is highly unlikely that at those shooting weights, people will be able to discern the differences in the actual holding weight from the different setup. Can you feel distinctly those kinds of differences? If you can, fair enough, if you can't, then don't worry about stacking.


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## Hank D Thoreau (Dec 9, 2008)

Flehrad said:


> People talk about 'stacking' all the time, but until you actually try the bow, you really have no good idea of the physical manifestation of the concept. I feel no stacking at all with my 27" riser and short limbs compared to my 25" riser and medium limbs. I'm lucky in that my draw length is pretty much 28", so I am not pushing the boundaries of the draw ranges, but if you look at the draw force curves measured by various people, the force differences can be quite small, and I believe that one particular Hoyt engineer was spot on in saying that, it is highly unlikely that at those shooting weights, people will be able to discern the differences in the actual holding weight from the different setup. Can you feel distinctly those kinds of differences? If you can, fair enough, if you can't, then don't worry about stacking.


With many shorter bows (i.e. 66 inch), I feel like I am hitting a wall. My 32 inch draw puts me in the very noticeable stacking range for many limbs. My HEX5 are the smoothest limbs that I have a full draw.


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## Flehrad (Oct 27, 2009)

Thats because you're shooting a 66" bow! At 32" draw you should be using a 72" bow...... but my point is if you are within the normal range for that bow length, using the 27" combination riser and limb may not necessarily provide stacking.


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## Borderbows (Apr 4, 2009)

Flehrad:
your last comment holds true... but please consider this:
We think that the term stack more discribes the more drastic hike in draw weight, when actually you could argue that stack is where the bow goes from a falling rate of increase to a climbing rate.

For example the inflection point on the graph would be that flat point between the preload bulge and stack.

We dirived a smoothness graph that shows this inflection point clearly. when the limb pulls less lbs per inch for the same weight than its equivelent pr model, then the bow is smoother.
The smoothness graph puts lbs gained per inch over draw length.
You can see a drop in lbs gained. then the onset of stack.
Any limb that drops in lbs gained the furthest is the better limb at the "smoothness" area of quality.

We here at Border would say that stack is not efficent, and the more you have the less efficent your being for the lbs your holding.
We try and avoid the "well, you cant really feel it" and go with the numbers, and try and eliminate it anyhow. We aim to make a better bow, even if you cant really feel it, we know its there.
This attitude has lead us to pushing the inflection point on a 70" bow out to 26-27" of draw opposed to the normal design remit of 20-21".
1" of change has been noticed by alot of archers, so imagine how smooth 4" more would feel like.
and infact our 60" bow with medium limbs prooved smoother than a normal 70" target bow. Less lbs pulled per inch even though it had more lbs on the fingers (3lbs more), between 29-30". This is past the remit of a 60" bow, and at the short end of the 70".


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## Flehrad (Oct 27, 2009)

But now you're moving away from talking about 'stacking' to 'smoothness', two different terms, for different aspects about bow setup..... I'm not really here to push definition differences and beliefs, but rather, the situation is more a 'personal' feel situation. It might be really noticeable for some, while definitely not, for others, stack and smoothness both.


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## zal (May 1, 2007)

With my current limbs, I couldn't feel any difference between 72 and 70 inch setup with my 32,75" draw. With some limbs the difference is greater but nothing that you couldn't get used to in few weeks. I recently went back to 70" setup.

String angle was more important factor to me than "smoothness", as I don't personally like extra smooth or non-stacking setups. A bit of stacking at the end of draw cycle helps my anchoring and release.


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## Borderbows (Apr 4, 2009)

ok, as ive said before... long limbs on a short riser will be smoother/stack less, than a same bow length but longer riser.
Taking the same long limbs and adding a 2" longer riser will do very little for this feeling as the sum of the moving parts is only 2" of string.
If you went for a longer bow, by way of limbs you get a smoother/stack free draw due to the fact that you have 2" more limb AND 2" more string.

stack and smoothness are the same thing. You cant have a smooth bow AND stack.
if you want a conventional limb but want smooth draw, then a 72" XL limb on a 25" riser is the way... then you can have anything inbetween, all the way down to a 66" bow with a 27" riser with some extra shorts.


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## zal (May 1, 2007)

Borderbows said:


> stack and smoothness are the same thing. You cant have a smooth bow AND stack.


Well, there are some limbs which distinctly do that. You can measure stack, but smoothness, I think, is something that's very personal to each archer.

For instance, I don't think border limbs "smooth" as the draw feeling isn't linear to me, you can feel clear "lump" in the beginning of the draw, similar to compound draw cycle. On the other hand, limbs like C+, sky's and masters' feel very linear and smooth to me.


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## Flehrad (Oct 27, 2009)

zal said:


> Well, there are some limbs which distinctly do that. You can measure stack, but smoothness, I think, is something that's very personal to each archer.


That is exactly my point, smoothness isn't necessarily the same as stacking. Longbows stack, but, they can be amazingly smooth to draw due to the very long 'limb' segment to the super short grip segment of 'riser'. It really comes down to how you draw the bow, if you draw in one straight consistent movement from brace height to anchor, or if you have a fast pre-anchor draw and then a slower controlled final approach to anchor etc. These factors determine smoothness for the individual using the limbs.

An example of this is the difference between F3 and F4 limbs from the Hoyt range. A lot of people say that the F3 limbs are really smooth. If you look at their draw force curves, they are nearly the same. I have drawn both F4 and F4, and I can't feel any difference. I shoot F4 limbs. But, how I draw, and how they draw, are different. It really comes down to personal preference for this, at least in my opinion.


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## Borderbows (Apr 4, 2009)

zal said:


> For instance, I don't think border limbs "smooth" as the draw feeling isn't linear to me, you can feel clear "lump" in the beginning of the draw, similar to compound draw cycle. On the other hand, limbs like C+, sky's and masters' feel very linear and smooth to me.


To be honest, we have noticed that Hoyt limbs gain better energy in the first handfull of inches of draw. This means that the inital bump that the Hoyt limbs is more pronounced than on the hex5 limbs... this gives them an advantage over us on stored energy, we have spent the last 2 years maintaining all the attributes of our R&D progression AND gain the same level of preload gain thats available on a Hoyt limb that we have not had till now. I have to disagree with your observations. but now feel we have acheived what hoyt have had, and say we are equal in the first several inches or draw... so we have improved the scale of the lump. this lumb, with the hex series limbs follows all the way out to 21" or so, unlike other limbs that tail off into the middle of the vally at this point. I would say that our limbs would have a lump mid point if anything. but this leads me to say that page three of this link answers your question.
under educated scrutiny, by independent observers, the hex5 has the most linear spring rate of the limbs in test.
afterall a limb is just a leaf spring 
http://www.archery-interchange.net/f127/hex5-alternative-use-first-impression-26106/index3.html

post 38 is your quote you need, for further information, so that you sont have to read the whole think if you dont want to.


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## boatsandarrows (Jun 1, 2011)

Flehrad said:


> You have to be careful with your calculations in what limb weight to get though since most limbs aren't given in specs relative to the 27" riser.


Is there a rule of thumb on how to calculate the difference in limb weight for different riser lengths (similar to the 2# per inch draw length rule)? I'm currently using club equipment with a 23" riser and 24# limbs. If I go with a 27" riser but want to keep the same draw weight, what limb weight should I go for? My DL is 30.5" if that factors in.


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## Hank D Thoreau (Dec 9, 2008)

Flehrad said:


> Thats because you're shooting a 66" bow! At 32" draw you should be using a 72" bow...... but my point is if you are within the normal range for that bow length, using the 27" combination riser and limb may not necessarily provide stacking.


Just to clarify, I shoot 70 inch bows but I have tried 66 inch bows belonging to others. Most 66 inch bows feel like I am hitting a wall. I have no problem with 70 inch bows and a 32 inch draw.


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## Borderbows (Apr 4, 2009)

boatsandarrows said:


> Is there a rule of thumb on how to calculate the difference in limb weight for different riser lengths (similar to the 2# per inch draw length rule)? I'm currently using club equipment with a 23" riser and 24# limbs. If I go with a 27" riser but want to keep the same draw weight, what limb weight should I go for? My DL is 30.5" if that factors in.


for an average lbs longbow, when you pike the design by cutting the limbs 1" each end you will see a hike in bow weight of about 2lbs.

same applies if you extend the riser and this trend seems available on the 23" to 25" risers. This assumes you keep the limb pocket angles constant.
Hoyt RX owners will probably note that they only have one marked draw weight on the limbs and there is no information to tell you which riser it is on.
there are two assumptions that can be made. one is that the limbs dont reach the marked weight on one of the two risers. Making either one feel tough to pull or one smooth for the marked weight...
the other assumption is that the limb pad angles have been adjusted, meaning that you cannot compair like for like on bow length since the bows are different bows.
for example, you would assume that going up a riser length would mean a weight drop of 2lbs, and if you adjusted the riser geom then your not compairing two different riser lengths, you would be compairing 2 variables, riser lengths compunded by limb pad angles.
I would be interested in finding an answer to this, as we cannot achieve the bow weight marked on our F4 limbs on a 27" riser even wound in. but we might have an odditie. 

This might just be a numbers game, of 1/3 of limbs are 1lbs over weight, and 1/3 of limbs 1lbs under weight, which means, 1/3 of limbs would be 3lbs under weight, This puts 1/3 will be within the +/-1lb industry standard... and while the rest will be within industry standard on one riser meaning 50% are ok, and 33% of the other half will also be ok on the longer riser.... odds are the limbs will be as marked...


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## Flehrad (Oct 27, 2009)

boatsandarrows said:


> Is there a rule of thumb on how to calculate the difference in limb weight for different riser lengths (similar to the 2# per inch draw length rule)? I'm currently using club equipment with a 23" riser and 24# limbs. If I go with a 27" riser but want to keep the same draw weight, what limb weight should I go for? My DL is 30.5" if that factors in.


As borderbows stated, as you go up in riser length, you drop off ~2lb. I have a pair of short 46lb limbs, that come in at 44lb on my 27" riser. Fully wound out at my draw length ~28" they come to 42.3lb (as measured using my Easton digital scales).

So, if you have 24lb limbs on a 23" riser, they currently act as 26lb limbs. Your draw length is 2.5" longer than 28" so thats +5lb, so you're shooting approximately 31lb.
So, in order to shoot the same poundage of 31lb, you would need limbs that act like 26lb, which means you would need 28lb limbs, assuming the same limb length used as you currently are using.

I think.


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## Borderbows (Apr 4, 2009)

Flehrad said:


> As borderbows stated, as you go up in riser length, you drop off ~2lb. I have a pair of short 46lb limbs, that come in at 44lb on my 27" riser. Fully wound out at my draw length ~28" they come to 42.3lb (as measured using my Easton digital scales).
> 
> So, if you have 24lb limbs on a 23" riser, they currently act as 26lb limbs. Your draw length is 2.5" longer than 28" so thats +5lb, so you're shooting approximately 31lb.
> So, in order to shoot the same poundage of 31lb, you would need limbs that act like 26lb, which means you would need 28lb limbs, assuming the same limb length used as you currently are using.
> ...


thats about right... we have had issues with people that wanted the same weight at 28" but had a 32" draw... We made a set of limbs to the industry standard of +/-1lb, and upon shooting them, they used several scales to find they that they were 2lbs under weight...
we shipped the limbs back for a checkup and noted that the limbs were as ordered, but the smoothness gave the archer 2.1lbs less on thier fingers.

The reason is this, the maths assumes a straight line on the DFC. 8" brace hieght, 28" draw means 40lbs is accumulated over 20" of draw. giving 2lbs per inch. but since almost all limbs are on the increasing lbs gained part of the DFC, they are gaining at 2.1lbs per inch up to 3lbs per inch from 28-29, and 31-31" respectivly. Ultra smooth limbs are gaining at 1.8-1.9lbs per inch. between this aspect and the +/-1lbs means your not getting what you thought...

The other anomaly is that the 10% weight adjustment on risers, works on this 2.1lbs concept, and when your only generating 1.8lbs per inch the 10% only becomes 7% weight adjustment. Thats the theory, it doesnt quite work out that way, there is a compromise... since you get an increased preload when you wind limbs in. Anyhow. you see where im coming from. There is smooth, and then there is ultra smooth, 2.1lbs is conventional smooth, 1.8lbs growth per inch though the clicker is smooth.

The problem is when debating smooth some people think thats its a linear rate of weight gain over the entire power stroke, Now decent bow maker wants this, as it incicates a huge amount of lost energy, what a bow maker wants is the least amount of weight gain in the few inches before and after the clicker zone.
Compounds are the opposite, in that they want maximum weight loss in many respects. Recurves cant loose weight, but you can hold back weight gain.
Any bow that gains above average though the clicker is starting to stack. so 2.1lbs on a 2lbs average is climbing. and bow sub 2lbs is smooth.


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