Changing limb length

Gee Emm Bee

New member
After a long layoff I've recently got back into archery. I'm using a bow which isn't exactly the correct length for me.
I'm drawing 26.5" arrow and my bow is 68". From charts I've looked at, 27" arrow seems to be at the short end of arrows suitable for a 68" bow
My limbs are just fibreglass and wood and I want to get carbon limbs so I plan to get short limbs to make a 66" bow.
With my present limbs at 34lbs OTF I can manage to reach 90m/100yds so I have to expect that carbon limbs should also be able to achieve that. I don't want to go to heavier limbs.
I'm wondering what differences I'll feel going from medium limbs to short limbs?
I understand the 'pinch angle' will be slightly tighter but I can't imagine that should be that much noticeable?
I feel that at my draw length I'm not bringing my 68" limbs up to their potential and that 66" limbs should be "a better fit" for me?

Open to opinions.

Bob
 

Rik

Supporter
Supporter
Um. 26.5 inch arrow would mean that your draw length was 27"+ and definitely not out of the 68" range... Going shorter would not necessarily give you any advantages, and may increase the amount of finger pinch.

With a similar draw length/shaft length, I went up from the short limbs I shot for years to mediums. I don't see any disadvantages, and it's reduced the amount of wear/callousing on my third finger.
 

Timid Toad

Moderator
Staff member
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Ironman
Depends on how you are measuring 26.5"
If it's to the button *this is incorrect* and you should add 1.75" to that (I know, daft but that's the rules).
I'm very fed up with correcting coaches who measure draw length to the button and send folk to shops for the wrong kit. So, if you wouldn't mind, please clarify, and go from there. :scratchch
 

Rik

Supporter
Supporter
Yes exactly....
With my current shaft length of 26 3/8 inches (ex points) my draw length should be a little over 27inches - a bit under 25.5" to the button. It's the draw length which is used as a guide for the bow length and as TT says, that's measured to the pivot point, plus 1.75".
 

Gee Emm Bee

New member
When at full draw with the point just coming through the clicker the groove in the arrow nock is 25.25" from the button.

Del - "Just fibreglass and wood" just means they're basic 'no frills' limbs . . . :cheerful:
 

Rik

Supporter
Supporter
When at full draw with the point just coming through the clicker the groove in the arrow nock is 25.25" from the button.

Del - "Just fibreglass and wood" just means they're basic 'no frills' limbs . . . :cheerful:
So 25.25 + 1.75 = 27 inch draw...
 

Timid Toad

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Yup, you're still in a medium. You *could* go down to a short, but as you are currently finding 100yds no problem, and intend to invest in carbon limbs which should be a little faster, I would stay with a medium set.
 
D

Deleted member 7654

Guest
When at full draw with the point just coming through the clicker the groove in the arrow nock is 25.25" from the button.

Del - "Just fibreglass and wood" just means they're basic 'no frills' limbs . . . :cheerful:
I find frills slow down limbs considerably ;) :rotfl:
Del
 

Gee Emm Bee

New member
I find frills slow down limbs considerably ;) :rotfl:
Del
That's why I went with the 'no frills' version!


Thanks guys for the comments so far.

Further comments welcome . . .

As I said I plan to upgrade to carbon limbs , but I won't be ordering online as I want to get a feel for what I get so it will mean a long day away to the nearest dealer. I hope to be able to compare short and medium limbs back to back.
My present limbs are marked 34# @ 28" in a 68" bow yet, when weighed at my draw length of less than 27" the scales are showing just on 34# and that's with the tiller bolts at their minimum setting so I'll be hoping to have my 'new' limbs weighed by 'accurate' scales.
 

Rik

Supporter
Supporter
Okay, standard spiel about limb markings...
First thing is, even if they are to spec and standard the weight can be +- 1 pound off the marked weight and still be considered correct.

But worse than that: there is no standard on how the marked weight is established. The best you can hope for, is that limbs from the same manufacturer as the handle will achieve the marked weight (+- 1 pound, at a standard 28" draw) at some point in the adjustment range. If you mix and match kit, you can't necessarily count on that.

And you can find odd errors - mismarking etc. One case I heard of had the limbs reversed (top for bottom) even.

So "try them, weigh them" is always advised.

My personal experience: Samick limbs on non-Samick handles, come up a little heavier than marked. Hoyt limbs seem to be marked at a mid-range weight rather than the lower end, so when wound down might be lighter than you expect. I suspect the Hoyt approach is better, as it gives adjustment room for "tuning" (setup) in both directions, but it's not common.
 

JohnK

Well-known member
ATA (formerly AMO) draw length is measured to the button + 1 3/4in, as mentioned above.

So your draw length is 27in, which is right in the sweet spot for short limbs on a 25in riser, making a 66in bow.

An acquaintance of mine - a former senior engineer at PSE Archery - once investigated the effect of changing limb length on arrow speeds. He found that all other things being equal, you can expect about a 2fps difference between limb sizes. That is, a 66in bow would be about 2fps than a 68in bow. That's not a huge difference, but it may be something to take into consideration.

You will also find a difference in the string angle. For me, this was the biggest change I noticed when I moved from 70in to 72in bows. My face shape is such that I prefer the flatter string angle of the longer bow. You may find it takes a little while to adjust to the sharper string angle of a shorter bow, but it may work very well for you.

Ultimately, if you can reach 90m with a 68in bow already there's no reason why you *have* to change to a shorter limb, but you can always give it a go :)

Good luck!
 

TJ Mason

Soaring
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American Shoot
The lower bracing height of the shorter bow will give a longer power stroke. Not by very much at all, but it's noticeable.

The bow may feel more punchy (which many find a good thing), and there may be a little more hand-shock. Hard to predict though - depends on the combination of riser, limbs and accessories.
 
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