Stiffening an arrow by reducing point weight.

I'm aware that it is possible to make an arrow stiffer by reducing the weight of the point, but does anybody know how much effect this can actually have ? For example, is it possible to stiffen an arrow by one whole degree of spine by doing this ?

I've recently increased the poundage of my bow with new limbs, and having checked a couple of arrow charts can see that my Carbon One 600 spine arrows are now a bit too weak, and that I should really be using the 550 spine. This is confirmed by some bare shaft testing.

The points in the 600 spine arrows are break-off points (90/100/110gr) - which I reduced down to 100gr some time ago.

If I reduce the weight still further down to 90gr, this will obviously stiffen the arrow further.


My questions are ................

Is it actually possible to make a 600 spine arrow behave like a 550 by reducing the point weight - or is the change not going to be that significant ?

Is there some way of measuring the actual stiffness of an arrow complete with it's point ?

And are there likely to be any other consequences of lowering the point weight to 90gr ?
 

blakey

Active member
I'm aware that it is possible to make an arrow stiffer by reducing the weight of the point, but does anybody know how much effect this can actually have ? For example, is it possible to stiffen an arrow by one whole degree of spine by doing this ?

I've recently increased the poundage of my bow with new limbs, and having checked a couple of arrow charts can see that my Carbon One 600 spine arrows are now a bit too weak, and that I should really be using the 550 spine. This is confirmed by some bare shaft testing.

The points in the 600 spine arrows are break-off points (90/100/110gr) - which I reduced down to 100gr some time ago.

If I reduce the weight still further down to 90gr, this will obviously stiffen the arrow further.


My questions are ................

Is it actually possible to make a 600 spine arrow behave like a 550 by reducing the point weight - or is the change not going to be that significant ?

Is there some way of measuring the actual stiffness of an arrow complete with it's point ?

And are there likely to be any other consequences of lowering the point weight to 90gr ?
Our James Park has shown that apparently you cannot do this. although countless archers (including myself) have been doing it for years. James says you will need to get the next spine. Or you will have to wind down your poundage. Static spine I think is the deflection cause by a certain weight. That cannot be altered by playing with points. However, if it was me I would try lighter points to see how they would bareshaft. Shortening the shaft by half an inch would stiffen it too, as would using pin nocks instead of G-nocks. Good luck. :)
 

PFC1968

New member
Unfortunately changing the point weight won't change the spine significantly, the wrong spine arrow will still be the wrong spine I'm afraid.
 

BillM

Member
Another thing to consider is that by using a lighter point, the arrow will be affected by side wind outdoors. I have changed the characteristics of arrows by moving to a lighter point but while they fly nicely indoors they get blown away in strong winds outdoors. I now use a slightly stiffer shaft with a heavier point outdoors. If your shafts were woodies, then a couple of coats of varnish tends to stiffen them up. I don't think that will work with composites (unless someone has tried it successfully!!!).

BillM
 

geoffretired

Supporter
Supporter
If you use break off points to change the weight, when you shorten the part that fits down inside the shaft, you effectively lengthen the amount of arrow shaft that is free to bend. That has the effect of lengthening the shaft and weakening it.
 

dfrois

Supporter
Supporter
In my limited experience, yes, a lighter point will make an arrow act stiffer, but it has to be a fairly large reduction in weight point. Ie., not 10 grains, more like 40 or 50 at least. Anything less will have a very (too?) small effect. The other consequence of lighter points, while changing nothing else, is that FOC will be reduced, and too little FOC (I think under 5 or 6%) is not good for arrow flight. And, in these conditions, the whole arrow will be lighter, and lighter arrows are more affected by winds...

Shortening a shaft, if possible, is a much better strategy for stiffening arrows.
JMHO, YMMV, etc...
:)
DF
 

AndyW

Well-known member
You can get that much difference by jiggery pokery but the shortening is by far a better idea. To stiffen up my 500s to what you would expect from a 450 I had to use 85 points down from 110 and add weight on the back by adding wraps, heavier vanes & nocks and adding nock collars - shame I couldn't just cut a bit off.
 

Ar-Pe-Lo

Member
I'm aware that it is possible to make an arrow stiffer by reducing the weight of the point, but does anybody know how much effect this can actually have ? For example, is it possible to stiffen an arrow by one whole degree of spine by doing this ?

I've recently increased the poundage of my bow with new limbs, and having checked a couple of arrow charts can see that my Carbon One 600 spine arrows are now a bit too weak, and that I should really be using the 550 spine. This is confirmed by some bare shaft testing.

The points in the 600 spine arrows are break-off points (90/100/110gr) - which I reduced down to 100gr some time ago.

If I reduce the weight still further down to 90gr, this will obviously stiffen the arrow further.


My questions are ................

Is it actually possible to make a 600 spine arrow behave like a 550 by reducing the point weight - or is the change not going to be that significant ?

Is there some way of measuring the actual stiffness of an arrow complete with it's point ?

And are there likely to be any other consequences of lowering the point weight to 90gr ?
10gn less will make no difference. But you can shoot weaker arrows obviously....as long as there is no contact with riser, you can shoot it no??
 

Rik

Supporter
Supporter
Add weight to the string or rear of the shaft. Decrease the BH. Shorten the shaft. Decrease the draw weight.
All those things will likely have more effect than knocking a few grains off the point weight. Only shortening or decreasing the draw weight are likely to have a large effect.
But if you're going to change the weight of the shaft, adding weight to the rear is more effective than taking it off the front.
 

dvd8n

Supporter
Supporter
AIUK Saviour
I have played with point weights and it made no appreciable difference to dynamic spine. It did change the impact height though.
 

jerryRTD

Well-known member
If you use break off points to change the weight, when you shorten the part that fits down inside the shaft, you effectively lengthen the amount of arrow shaft that is free to bend. That has the effect of lengthening the shaft and weakening it.
Only if the point shaft is a tight fit. The point on my ACEs have a shaft smaller than the internal diameter of the arrow ,allowing the shaft to flex with out touching the point.
 
Many thanks for all of your clear & helpful answers. As ever, this place really is a goldmine of useful tips and deep knowledge.

It seems clear that just decreasing the point weight by another 10gr really isn't going to make any significant difference.

Also I can see now that when I originally removed the first 10gr AND reduced the arrow length by 1" at the same time - the difference that I experienced was obviously mostly down to the shortening rather than the lightening.

Thanks to your warnings, I won't be attempting to lighten the points any further, as the place that I shoot is a particularly windy field.

The shafts are now as short as they can be, and the draw weight is at the minimum for the new pair of limbs. But, the idea of adding some weight to the back of the arrow is an intriguing one.

I'm currently using push-in G Nocks but will try a couple of arrows with the heavier pin nocks and see what happens.

Many thanks once again for all of your help.



 
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