Limbs Draw length V Bow length

SimonS

Member
I have a question regarding what draw length nececcitates the move up (or move down for that matter) from a 68" bow to a 70" bow.
Current set up is Hoyt HPX 25" with long Formula excel limbs, just increased the pountage to 36.5lbs on my fingers through the clicker. Arrows are ACC (need to check what exact spine) but within the recommended group at 29.5" draw length, and they come out of the bow and shoot well.
Tried to get a sight mark at 100yds last night without any luck, arrows falling short, even when aimimg at the clouds above the target.
I know the ideal answer is, new lighter arrows, possible heavier limbs, but I am working back from a shoulder injury and cant really go above 36/37lbs at the moment and dont have the funds for a new set of ACE's or X10's (also tried some 520 spine ACE's last night and still just low on the target - so dont see that as a solution)
So looking on all the FB selling sites and the usual second hand market locations, i am finding some 'Medium' limbs available, Quattro's and F7's which I know are 'Faster' limbs that my entry level Excel's but I have always shot with a 70" bow (long limbs).

Any thoughts on the Pro's Con's of reducing the bow length, string angle, nock pinch etc are welcomed - basically I need more speed from the limbs, will I get away with medium limbs ?
 

geoffretired

Supporter
Supporter
From your post it sounds as if your anchor point is high up, close to your aiming eye.
It might be worth trying a platform on your tab, to lower the draw hand. Is your sight close in to the bow?
 

SimonS

Member
Its a valid point and i will get someone to look at this in the club, bur pretty sure its down under the jaw bone and I am using a Saker tab with the small metal platform, shot with this for about 4 years now so pretty consistent with it.
Forgot about the sight info - yes its all the way in as far as it will go and the elevation is set as low as possible before i get fletching contact with the pin. Its that low that I cant see the target for the end of the long rod (I have a long - long rod so can use a shorter one, thats not a problem).
 

backinblack

Active member
Hi Sizzler,

Sorry to state the bleeding obvious, but the way to find out is to borrow a mate's 68 inch bow and have a bit of a shoot to see how it goes. I'm in a similar position in that I'm on the cusp of 66 or 68 inch bows and have no problems shooting a 66 (at least no new ones) rather than a 68, but YMMV. You're clearly aware of the possible pros and cons but you have to see how well the shorter bow fits you.

One obvious con for me would be spending the money on shorter limbs only to find that you make no significant improvement to your sight marks: after all 37lbs is still 37lbs and, whilst theoretically you might get an additional something (other than stacking) by working a shorter pair of limbs harder, you may not.

I would have thought (finger in the air) that you would have gotten more in terms of sight marks from switching to a pair of ACEs than using a shorter pair of limbs, yet you seem to think that this alone wasn't sufficient from what you said, so I'd be inclined to think that the limb change might not give you too much more, but again this is something you need to try out before spending the cash if you can.

You are probably aware of all this stuff but if you haven't already, you could try:

A platform tab;
Less strands in your string;
A faster string material;
Trimming any excess length from the arrows
Spin wings as opposed to plastic fletchings;
A lighter point;
Getting rid of any inserts at the back of the arrow;
Losing a brass nock set if you are using one.
 

SimonS

Member
Hi Sizzler,


I would have thought (finger in the air) that you would have gotten more in terms of sight marks from switching to a pair of ACEs than using a shorter pair of limbs, yet you seem to think that this alone wasn't sufficient from what you said, so I'd be inclined to think that the limb change might not give you too much more, but again this is something you need to try out before spending the cash if you can.

You are probably aware of all this stuff but if you haven't already, you could try:

A platform tab;
Less strands in your string;
A faster string material;
Trimming any excess length from the arrows
Spin wings as opposed to plastic fletchings;
A lighter point;
Getting rid of any inserts at the back of the arrow;
Losing a brass nock set if you are using one.
Backinblack:

Tried a set of 30.5" lond ACE's 520 spine (so slighty longer that i need but not that long they would be same weight as my ACC's) they dropped onto the boss but right at the bottom and i was aiming in the white at the top.
Already shooting with a platform tab - consistent anchor point.
Not tried less strands - how much of a difference will this actually make ?
I use Nitro strings and pretty happy with them.
Arrow length is about 1.25" beyond the button so as short as possible at the moment.
Not tried spin wings but woukld they give extra distance ?
Need to check the point weight - think they are 80's at the moment. Lighter point wil stiffen the arrow ?
Just the ususl uni-bush and push in easton plastic nock in the end
Nocking points are whipping not brass.
 

geoffretired

Supporter
Supporter
The reason I mentioned a platform is that in the 80's with a 69" bow and fat ally arrows I could reach 100y. My draw weight would have been similar, I had lighter limbs but slightly longer draw length. The thing that might be different is face length which in my case, if I have a longer face than you would lower the back of the arrow in relation to my aiming eye. One way to lower the back of the arrow if you have a short face, is to put some packing on the platform to drop the draw hand with the packing is rubbing under your jaw.
 

Rik

Supporter
Supporter
Nocking point too high? That can make a significant difference at longer distances. Similarly: tiller? (tied to nocking point).
 

nbuuifx

Member
I tried once at 90m which is nearly 100 yards. I have 500 spine acc arrows which are a little stiff. Pulling about 34lbs and I can hit the target. With the sight all the way in, I had to aim at the top. With the sight inverted I was able to aim at the gold. My accuracy was poor though. Usually 5 somewhere on the target and one miss.

My group size was about 120cm!

I do have xs spin wings if they help
 

KidCurry

Well-known member
AIUK Saviour
Nocking point too high? That can make a significant difference at longer distances. Similarly: tiller? (tied to nocking point).
Does nocking point make a difference on a recurve? Given the arrow nock is between the fore and middle finger at a set point below the jaw anchor point, irrespective of where the nock is on the string, the arrow angle of elevation will be the same, albeit the tiller will be slightly out :)
 

geoffretired

Supporter
Supporter
Does nocking point make a difference on a recurve? Given the arrow nock is between the fore and middle finger at a set point below the jaw anchor point, irrespective of where the nock is on the string, the arrow angle of elevation will be the same, albeit the tiller will be slightly out
You got me thinking on that. heehee!
I had to imagine the archer at full draw in both situations. With the bow set up well; and then with the nocking point raised.
I imagined the archer at full draw and on aim; then imagined he/she stood still while the nocking point was raised.
Ignore the impossibility of adjusting the nocking point while the bow is at full draw. Imagine just the string sliding down through the nock sets( as if loose).
As that happens, the arrow remains in its original position, same position at the fingers and same elevation.
What also happens is the riser tilts back a bit, and the sight tilts up a bit, and the archer is now aiming high, so they lower the bow arm to bring the sight down and the arrow drops at the front, too.
Plus, the arrow point being at a lower angle in relation to the direction of travel of the nocking point, it gets a less direct push from the string, causing it to tip up at the tail and lose energy sorting itself out.
 

Ski

The American
Ironman
American Shoot
Post me a video of you shooting and I will tell you what`s wrong.
If you have a you tube channel - upload the video there, keep it private and send the link.

A forum will not help - a visual will be much better.
 

JohnK

Well-known member
Assuming a conventional recurve limb, such as you have, there is very little difference in speed between each bow size, all else being equal.

I knew a senior engineer for a major manufacturer who ran some tests on this. He found only a 2fps difference between each bow length; so a 68in bow was only 2fps quicker than the 70in equivalent.

There are things that can make a difference, such as an excessively high nocking point, as others have already mentioned. However, I concur that seeing video of you shooting would make it easier to give specific advice if your form is partly the reason for your sightmarks.
 

SimonS

Member
Nocking point too high? That can make a significant difference at longer distances. Similarly: tiller? (tied to nocking point).
Another good point Rik - nocking point is 1/8" (3mm) above arrow rest.
I am pretty confident the bow is set up correct, over 7 years experience now as an archer.
I do accept that my form may not be what it was before my shoulder injury, but coming out of indoors shooting 575 ish scores on a Portsmouth, surely i cant be that bad that form is the problem at 100 yds. On the plus side, teh arrows were nicely grouped in the grass almost every end i tried at 100 !
I am more intetested in the benefits/negatives of switching from a 70" bow to a 68" bow with a long 29.5" draw length ?
 

Whitehart

Well-known member
The draw weight has a big effect on the real results on an archery field and trying to shoot the longer distances. Perhaps not with the 0.5% of serious archers in the UK shooting 45lb plus, but the majority of club archers shooting sub 38lb. The lower the draw weight the more important it is to not try and go longer. It might feel smoother to draw, but you are working the limbs at the lower end of the efficiency range (or even outside) and lb for lb you are not getting out what you put in. The situation gets worse with extreme curve limbs as you are not pulling them far enough back to get the limbs to work.

Even top archers I know opting for a longer bow than their draw length would suggest find that they need to up the poundage of the limbs from 2-4lb to get the same sight marks and bow efficiency which is no big deal for them, but for most of us that is a lot of extra unnecessary draw weight.

Obviously, there are lots of reasons why somebody might not be able to get a sight mark for a longer distance (technique and equipment) but shooting a too long recurve bow is one of the most common - there is no free lunch in archery :)

This is not just based on theory but time and time again when people buy their kit, especially when we are helping them to hit the longer distances because they get are getting older and need to drop draw weight or not training as much as they were before.

A ballistic arrow speed test does not highlight the loss of forward energy at the longer distances and a drop in scores (look at longbow ballistic arrow speeds) -a result of an arrow slowing down and being more affected by the elements resulting in bigger groups.
 

Whitehart

Well-known member
OK - straight forward answer - thanks
Any down sides ? nock pinch, string angle, stacking etc ?
Unless you have really big fat fingers no not at 29.5, although the head can play games with your confidence - I had an archer who always shot a 70" bow but shot better (better sight marks and scores) with a 68" (correct length) but he could not get out of his head that he always shot a 70" bow so he changed back???? and accepted lower scores......

Some really cheap limbs might not feel great at full draw but going to 70" is not the answer buy a different cheap limb.
 

KidCurry

Well-known member
AIUK Saviour
Unless you have really big fat fingers no not at 29.5, although the head can play games with your confidence - I had an archer who always shot a 70" bow but shot better (better sight marks and scores) with a 68" (correct length) but he could not get out of his head that he always shot a 70" bow so he changed back???? and accepted lower scores......

Some really cheap limbs might not feel great at full draw but going to 70" is not the answer buy a different cheap limb.
The change in angle of the string at the fingers for a 30" draw, between a 70" bow and 68" bow is a tad over 1⁰ from 132.4⁰ to 133.6⁰. Pretty much bugger all :)
 

SimonS

Member
The change in angle of the string at the fingers for a 30" draw, between a 70" bow and 68" bow is a tad over 1⁰ from 132.4⁰ to 133.6⁰. Pretty much bugger all :)
OK - thats interesting, thanks for the accuracy here - proves a point. So it looks like a 68" bow with a set of Quattro's or F7's (If I can find some) will move me in the right direction ?
 

dvd8n

Supporter
Supporter
AIUK Saviour
Assuming a conventional recurve limb, such as you have, there is very little difference in speed between each bow size, all else being equal.

I knew a senior engineer for a major manufacturer who ran some tests on this. He found only a 2fps difference between each bow length; so a 68in bow was only 2fps quicker than the 70in equivalent

That's very interesting considering that it goes against conventional wisdom - or at least declares the effect negligible.

I feel better about going with XLs to compensate for my gorilla arms now.
 
Top