Holes in your bow



This has become quite a long thread. To see some hard facts without having to wade through everything, you might want to go straight to Brian LaBorde's contribution.


Re: Holes in your bow From: Hywel Owen <h.owen@dl.ac.uk> Date: Mon, 29 Jan 1996 13:59:35 +0000 Martin Leach wrote: > > >>Hywel Owen > >>'What are those holes in your bow for? > >> Are they to let the wind through?' > > Basically yes!! they are. the holes oin the radian and other > recurves and compounds reduce the physical area of the bow > and thus if shooting in a wind the force exerted on the bow > by the wind is reduced > > it has to be one of the <slight> advantages to shooting in the wind! > > Martin Leach Although my previous end of message comment was meant in jest (I'll put a :> after them next time!), it seems as though some people seriously think that holes in a riser do something useful for aiming in the wind. I'm very sceptical about this, and don't believe that it is more than an archery myth. What do other people think? NB: Really, no joke, I'm actually interested in what people think about this! Hywel Owen
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Re: Holes in your bow
From           Hywel Owen <h.owen@dl.ac.uk>
Date           Mon, 29 Jan 1996 17:23:46 +0000


Philip Fites wrote:
> 
> OK, I'll bite.  Holes do three things: they change the center of mass
> and perhaps the distribution around the center; they make the riser lighter;
> and they do indeed allow wind to pass through.
> 
> All of these things are uite easily measurable.  The effect of slightly lower
> area for the cross-wind vector component of a wind on the pressure applied
> to the riser also is easily measurable.  I have not done any studies, but
> my guess is that the (rather more subjective) effect of all this on shooting
> results is very small.
> 
> Oh -- holes also do a fourth thing: they make the riser weaker tha  if
> it had no holes, to some sorts of stresses.  Also measurable (and calculable
> too; it's standard materials engineering.)  This is unlikely to affect
> shooting unless there are so many or so large holes that rigidity is
> seriously compromised.  Or strength, so that it breaks ... :-)
> 
> My $.02 worth ...
> 
> ==Phil Fites


I received this via email - thanks for the reply. The stuff about 
riser stresses, elasticity and changes of weight and weight 
distribution compared to a riser with no holes is all pretty well 
known, but I'm still sceptical about this wind on the riser stuff. 
Can anyone give a more convincing argument about the aiming effects 
of a riser with holes in it? It may be easily measureable, but has 
anyone actually done it?

Hywel Owen

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From           ianh@liverpool.ac.uk (Mr I.M. Hannaford)
Date           Mon, 29 Jan 1996 17:27:52 GMT


In article <310CD2C7.1E02@dl.ac.uk>, Hywel Owen <h.owen@dl.ac.uk> writes:
> Martin Leach wrote:
> >  
> > >>Hywel Owen
> > >>'What are those holes in your bow for?
> > >> Are they to let the wind through?'
> > 
> > Basically yes!! they are.  the holes oin the radian and other
> > recurves and compounds reduce the physical area of the bow
> > and thus if shooting in a wind the force exerted on the bow
> > by the wind is reduced
> > 
> > it has to be one of the <slight> advantages to shooting in the wind!
> > 
> >    i^^^^^i                       Martin Leach
 
> 
> Although my previous end of message comment was meant in jest (I'll 
> put a :> after them next time!), it seems as though some people 
> seriously think that holes in a riser do something useful for aiming 
> in the wind. I'm very sceptical about this, and don't believe that 
> it is more than an archery myth. What do other people think?
> 
> NB: Really, no joke, I'm actually interested in what people think 
> about this!
> 
> Hywel Owen
> h.owen@dl.ac.uk


Just a thought, but I always thought that the problem with shooting in 
the wind was the action of the wind on the archer. I'm sure that the 
cross-sectional area of an average archer (and some of us can be pretty large)
is a lot bigger than any bow I've ever seen.

Maybe the holes in the Radian (amongst others) are simply to decrease the mass
of the thing. I know that by the time I've saved up enough to buy one, I'll 
be unable to lift a solid lump of metal, unless it's my Zimmer frame.

Ian Hannaford
Captain, Liverpool Archery Club

P.S.    Hywel.

What are you doing now? Does Manchester Uni' still have a team? There's going
to be a Christie Cup match soon and we need to know wether to include them or
not.

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From           OHAYON  JONATHAN <ohayon@ecf.toronto.edu>
Date           Mon, 29 Jan 1996 19:34:01 GMT


> Although my previous end of message comment was meant in jest (I'll 
> put a :> after them next time!), it seems as though some people 
> seriously think that holes in a riser do something useful for aiming 
> in the wind. I'm very sceptical about this, and don't believe that 
> it is more than an archery myth. What do other people think?
> 
> NB: Really, no joke, I'm actually interested in what people think 
> about this!

Good question.  I think there is definatley a difference though the 
magnitude I am not sure of.  One of the arguments I have heard against it 
is that the arm has just as much surface area then the bow thus the 
diffrence cutting holes out of the bow makes is negligible...  I don't 
agree with this... After all the bow is at the farthest distance from the 
pivot point (your shoulder) while a lot of your arm is close to the pivot 
point... anyone who knows about MOMENTS, will know that since the 
moment=perpindicular force * distance from pivot point, the bow has a 
much greater effect on the motion (for example try lifting something 
heavy by holding a crowbar by the object... then try lifting it by 
holding at the other end of the crowbar... ).  Anyways... I don't think i 
should be pretty hard to figure this all out so if anyone wants to just 
calculate surface area of bow (with and without holes), and average 
surface area and length of arm we could get a rough estimate... and I 
mean ROUGH.... You'll probably notice a much larger difference on a bow 
like the Avalon which has large windows :> then a bow like the sky conquest 
that has small windows (I wouldn't hold that against the sky though as it 
is a great bow.).

Of course, we could all just work out a little more so that we don't get 
pushed around by the wind as much instead of constantly complaining about 
it :>

Jonathan

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From: Claes.Colmeus@farm.lu.se (Claes Colmeus)
Subject: Re: Holes in your bow
Date: Tue, 30 Jan 1996 10:05:31


In article <310D02A2.18D0@dl.ac.uk> Hywel Owen <h.owen@dl.ac.uk> writes:
>From: Hywel Owen <h.owen@dl.ac.uk>
>Subject: Re: Holes in your bow
>Date: Mon, 29 Jan 1996 17:23:46 +0000

>Philip Fites wrote:

<snippetysnip>

>> Oh -- holes also do a fourth thing: they make the riser weaker than  if
>> it had no holes, to some sorts of stresses.  Also measurable (and calculable
>> too; it's standard materials engineering.)  This is unlikely to affect
>> shooting unless there are so many or so large holes that rigidity is
>> seriously compromised.  Or strength, so that it breaks ... :-)

Not necessarily so. In fact, correctly shaped and placed holes can 
actually improve strength by distributing stress concentrations. Have you ever 
tried to tear perforated  paper? Does it ever part in the perforation? It can 
be shown, even in theory, that a reasonable amount of perforation, especially 
with round holes, will improve the strength of any sheet material. However, 
please try to convince me that anything but appearance dictates the 
shape and placement of the holes in our bow risers. 

My Browning Olympian is richly graced with holes. One of them, above the 
handle, is perfect for holding the bow for small adjustments etc even with the 
arrow on the string. Just put a finger through the hole and the other hand is 
free for use. The balance is perfect. 

>I received this via email - thanks for the reply. The stuff about 
>riser stresses, elasticity and changes of weight and weight 
>distribution compared to a riser with no holes is all pretty well 
>known, but I'm still sceptical about this wind on the riser stuff. 
>Can anyone give a more convincing argument about the aiming effects 
>of a riser with holes in it? It may be easily measureable, but has 
>anyone actually done it?

I can't. Compared to wind effect on limbs, stabilizers (and archer) the effect 
must be very small indeed. I've never blamed a miss on the lack of holes in 
the riser (my old faithful Atletic had none of the stuff). The holes were NOT 
my main reason to get a Browning instead.

Happy shooting, even in the wind.

Claes

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From: dna1000@cus.cam.ac.uk (David Allsopp)
Subject: Re: Holes in your bow
Date: 30 Jan 1996 12:50:51 GMT


In article <Claes.Colmeus.11.000A17DB@farm.lu.se>,
Claes Colmeus <Claes.Colmeus@farm.lu.se> wrote:

[crossposted to sci.materials]
[Note for sci.materials readers - this thread concerns the milling/drilling
of holes in the alloy centre section (riser) of archery bows]

>>> Oh -- holes also do a fourth thing: they make the riser weaker...

>Not necessarily so. In fact, correctly shaped and placed holes can 
>actually improve strength by distributing stress concentrations. 

Are you sure about this? Holes *create* stress concentrations. The only
case I can think of where a hole improves the stress distribution is if
it is drilled at the apex of a crack or notch, thereby blunting the notch.
(eg drilling holes at each end of a crack in a perspex sheet to stop the
crack growing)

Have you ever 
>tried to tear perforated  paper? Does it ever part in the perforation? 

Yes, usually.

It can 
>be shown, even in theory, that a reasonable amount of perforation, especially 
>with round holes, will improve the strength of any sheet material. 

Do you have any references/calculations for this effect? I'm very interested.

However, 
>please try to convince me that anything but appearance dictates the 
>shape and placement of the holes in our bow risers. 

Very true...

The holes will certainly reduce stiffness. I remain to be convinced that
they can do anything but reduce strength.

David.

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From: Hywel Owen <h.owen@dl.ac.uk>
Subject: Re: Holes in your bow - Riser Strength
Date: Tue, 30 Jan 1996 14:00:03 +0000

David Allsopp wrote:
> 

> 
> However,
> >please try to convince me that anything but appearance dictates the
> >shape and placement of the holes in our bow risers.
> 
> Very true...
> 
> The holes will certainly reduce stiffness. I remain to be convinced that
> they can do anything but reduce strength.
> 
> David.
> 

Although my initial question was about the effects of wind on a 
riser, it seems as though there is much debate on the effect of 
holes on risers.

It seems obvious to me that if you remove material from a bar (i.e. 
a riser), then its stiffness will reduce. However, the point is that 
if you want to use a particular total mass of metal in a riser, it's 
better to put it where stresses are greater; this is the same reason 
why I-beams are used in engineering applications. A riser with holes 
in will be stronger than a riser (of the same mass) without holes  
(provided the holes are in the right places!).

A related phenomenon exists in terms of material use in risers. 
Magnesium alloys are generally less dense than Aluminium alloys, but 
they are also weaker. Therefore, when casting a Magnesium riser, 
more material must be used to give the required strength - the final 
riser will be thicker than an Aluminium one, but generally will have 
the same mass and strength.

Any thoughts, folks?

Hywel Owen

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From: ldiehr@eth233.eld.ford.com (L S Diehr (Lawrence))
Subject: Re: Holes in your bow
Date: 30 Jan 1996 14:40:50 GMT

Hywel Owen (h.owen@dl.ac.uk) wrote:
: Martin Leach wrote:
: >  
: > >>Hywel Owen
: > >>'What are those holes in your bow for?
: > >> Are they to let the wind through?'
: > 
: > Basically yes!! they are.  the holes oin the radian and other
: > recurves and compounds reduce the physical area of the bow
: > and thus if shooting in a wind the force exerted on the bow
: > by the wind is reduced
: > 
: > it has to be one of the <slight> advantages to shooting in the wind!
: > 
: >    i^^^^^i                       Martin Leach

: Although my previous end of message comment was meant in jest (I'll 
: put a :> after them next time!), it seems as though some people 
: seriously think that holes in a riser do something useful for aiming 
: in the wind. I'm very sceptical about this, and don't believe that 
: it is more than an archery myth. What do other people think?

: NB: Really, no joke, I'm actually interested in what people think 
: about this!

: Hywel Owen
: h.owen@dl.ac.uk

The holes serve the same purpose as the holes in Swiss Cheese.  They 
provide a place for archers to store small amounts of stale air that 
can be reclaimed in times of great angst and released on the unsuspecting
shooting line along with appropriate sound effects.  

Larry Diehr

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From: j.m.muller@student.utwente.nl (Marcelo Muller)
Subject: Re: Holes in your bow - Riser Strength
Date: Tue, 30 Jan 1996 19:28:12 UNDEFINED

In article <310E2463.46D2@dl.ac.uk> Hywel Owen <h.owen@dl.ac.uk> writes:

<Snip David Allsopp's part>

>It seems obvious to me that if you remove material from a bar (i.e. 
>a riser), then its stiffness will reduce. However, the point is that 
>if you want to use a particular total mass of metal in a riser, it's 
>better to put it where stresses are greater; this is the same reason 
>why I-beams are used in engineering applications. A riser with holes 
>in will be stronger than a riser (of the same mass) without holes  
>(provided the holes are in the right places!).

>A related phenomenon exists in terms of material use in risers. 
>Magnesium alloys are generally less dense than Aluminium alloys, but 
>they are also weaker. Therefore, when casting a Magnesium riser, 
>more material must be used to give the required strength - the final 
>riser will be thicker than an Aluminium one, but generally will have 
>the same mass and strength.

>Any thoughts, folks?

Well, yes:

The density of magnesium alloys is lower than aluminium. So, if you make an 
aluminium handle of the same shape (read: volume) you will end up with more 
mass. 

The first Stylist handles (not the Supreme) were made more or less as a copy 
of the conventional magnesium handles. The one I once held, felt quite heavy, 
heavier than magnesium handles.Can someone confirm this ( Stretch :-) ?

As aluminium is probably stronger, you can remove the material were it is not 
necessary, in the manner Hywel described. Hence: holes.
I must say Hoyt have done this very well on the Radian. The bottom part of 
the handle is machined from the side, but also perpendicular to it. I don't 
think there is much unnecessary material there.

So, IMHO, the main reason to put holes in (machined) risers, is to keep their 
weight acceptable.

Of course, everything with a :-)

Marcelo Muller

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From: Rick Mott <rick>
Subject: Re: Holes in your bow
Date: Tue, 30 Jan 1996 21:51:27 GMT

dna1000@cus.cam.ac.uk (David Allsopp) wrote:
>In article <Claes.Colmeus.11.000A17DB@farm.lu.se>,
>Claes Colmeus <Claes.Colmeus@farm.lu.se> wrote:
>
>[crossposted to sci.materials]
>[Note for sci.materials readers - this thread concerns the milling/drilling
 ------ skip lots of stuff ----
>Have you ever 
>>tried to tear perforated  paper? Does it ever part in the perforation? 
>
>Yes, usually.
 ^^^^^^^^^^^^
I have to agree with this.  I try it fairly frequently with toilet paper,
and find it works quite reliably :)

        Rick Mott
        
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From: jagj@rhyolite.win-uk.net (John  Jones)
Date: Tue, 30 Jan 1996 10:16:41 GMT
Subject: Re: Holes in your bow

 
In article <310CD2C7.1E02@dl.ac.uk>, Hywel Owen (h.owen@dl.ac.uk) writes:
>Martin Leach wrote:
>>  
>> >>Hywel Owen
>> >>'What are those holes in your bow for?
>> >> Are they to let the wind through?'
>> 

>Although my previous end of message comment was meant in jest (I'll 
>put a :> after them next time!), it seems as though some people 
>seriously think that holes in a riser do something useful for aiming 
>in the wind. I'm very sceptical about this, and don't believe that 
>it is more than an archery myth. What do other people think?
>
>NB: Really, no joke, I'm actually interested in what people think 
>about this!
>
>
Isn't it really to reduce weight?  Though there was a lot of
cobblers in the Radian advertisements about letting the
vibration out ...

In out club championship, the side wind was so bad, I had to
take the longrod off :(

 
John Jones

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From: angus@harlqn.co.uk (Angus Duggan)
Subject: Re: Holes in your bow
Date: Tue, 30 Jan 1996 09:29:14 GMT

In article <DLyDuG.IAG@liverpool.ac.uk> ianh@liverpool.ac.uk (Mr I.M. Hannaford) writes:
>Maybe the holes in the Radian (amongst others) are simply to decrease the mass
>of the thing. I know that by the time I've saved up enough to buy one, I'll 
>be unable to lift a solid lump of metal, unless it's my Zimmer frame.

I've always considered the holes in the Radian to be a weight-reducing device
(since the alloy is dense enough that even with holes, it's as heavy as a cast
riser). The lowering of wind resistance is negligible, you're right that it's
the effect of the wind on the archer that is more important.

Angus Duggan

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From: jdickson@festival.ed.ac.uk (John Dickson)
Subject: Re: Holes in your bow - Riser Strength
Date: 31 Jan 1996 10:33:15 GMT

Well my newsfeed is a little slow this week so you'll have to excuse me
for joining the party late:

j.m.muller@student.utwente.nl (Marcelo Muller) writes:

>Well, yes:

>The density of magnesium alloys is lower than aluminium. So, if you make an 
>aluminium handle of the same shape (read: volume) you will end up with more 
>mass. 

Indeed, all you hav to do is look at Marksman bows which use Aluminium rather
than Magnesium alloy. Their profiles are very small (compared with say a
Hoyt TD4 or an Alpha EX) but then again they require more stringent
quality control. You're using less volume material therefore any casting
impurity has a bigger percentage effect.

>The first Stylist handles (not the Supreme) were made more or less as a copy 
>of the conventional magnesium handles. The one I once held, felt quite heavy, 
>heavier than magnesium handles.Can someone confirm this ( Stretch :-) ?

The Stylist has gradually got lighter since 1990 when it first appeared
on the scene. It draws strongly on Nishizawa and Greenhorn designs but
was a complete design in itself (23" handle not 25"). It is also much
thinner than any cast bow.

The original Stylist (before they chamfered the edges) weighed about
1.2kg. This was heavy compared with Cast bows but then again it is over
2x stronger. The Stylist now weighs about 1.17kg. The saving being the
edges and the change from powder coat paint to anodising.

The point is that when shooting it you just don't notice the weight
because it's well balanced. Weight doesn't seem so important in the eyes
of the buyer these days (unless you shoot an Eolla or a Carbofast
Diamond Star), the Radian and the Greenhorn Diamond are both heavier
than the Stylist (so I'm told?) 

>As aluminium is probably stronger, you can remove the material were it is not 
>necessary, in the manner Hywel described. Hence: holes.

The Stylist Supreme came about because Steve Lingwood wanted a bow with
holes (purely for sales reasons) it actually got designed because Steve
Hallard decided he wanted a 25" handle and holes were necessary or bow
mass was going to go up. (Hallard was strongly opposed to the early
"Supreme" prototypes which were just Stylists with holes...still shoots
quite nicely tho ;-)

Another factor here is the grade of Alloy used, better grade alloy =
bigger holes (or same holes and stronger bow) 

>I must say Hoyt have done this very well on the Radian. The bottom part of 
>the handle is machined from the side, but also perpendicular to it. I don't 
>think there is much unnecessary material there.

The Radian is pretty isn't it? ;-) Also a feature of the Greenhorn
Diamond (except the hole is at the front) and the Supreme.

>So, IMHO, the main reason to put holes in (machined) risers, is to keep their 
>weight acceptable.

Certainly that should be the reason. I think Spigarelli were the first
manufacturers of MACHINED handles with holes (? no, Border Mistral was cast)
their target was to keep the weight close to that of the TD4+...hence
holes were necessary.

Nowadays holes are as much for aesthetics, manufacturers can't sell a
bow without holes unless it has another gimmick (Eolla ~ shape,
Carbofast Diamond ~ Carbon).

I'd be quite happy to shoot any of the top range bows at the moment (not
the TD4+ we don't get on ;-), maybe not the Greenhorn Diamond either)
all these handles offer pretty much the same, to differring degrees, a
stable launching point for a good set of limbs. If your limbs are kack
then your riser can be as super dooper as you like and it'll still shoot
crap!

So what's important? It's important that you want to shoot the riser you
are shooting and not the riser someone else is shooting, aesthetics play
a major role in some archers *mind game*....me included ;-)


John Dickson,(aka Stretch)

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From: tim@housenet.demon.co.uk (Tim Mundon)
Subject: 'holey' risers batman!
Date: Wed, 31 Jan 1996 21:47:36 GMT

On Mon, 29 Jan 1996 13:59:35 +0000, Hywel Owen <h.owen@dl.ac.uk>
wrote:
I must appologise for a software malfunction, in fact I wrote the
following:
 
>> >>Hywel Owen
>> >>'What are those holes in your bow for?
>> >> Are they to let the wind through?'
>> 
>> Basically yes!! they are.  the holes oin the radian and other
>> recurves and compounds reduce the physical area of the bow
>> and thus if shooting in a wind the force exerted on the bow
>> by the wind is reduced
>> 
>> it has to be one of the <slight> advantages to shooting in the wind!
>> 
>>    i^^^^^i                       Martin Leach
>>    |/_-_\|                martin@housenet.demon.co.uk
>>  __(  |  )__    ***********************************************
>> (   \_-_/   )   God is REAL, unless explicitly declared INTEGER
>
>
>

It seems people may have mistaken the context that this was written
in.
   The fact that holes are in risers are for three dinstinct points:

1)      To reduce the physical weight of a solid aluminium handle

2)      To reduce the sideways force exerted on the bow by the wind

3)      So that it looks Good!!!   


In justifying the second reson, I must point out a few misconceptions
that have sprung up in this area, firstly when the wind blows while
you are at full draw it has an affect on three things 1, your bow 2,
your bow arm & 3, your body. Now when the wind is blowing very hard
then there is little other than your shooting style that will help
you. But with smaller breezes, the wind blowing on your body will have
little affect because of your mass. 
        As you move away from the pivot point of your shoulder, down
the bow arm, the force required to produce a noticable affect
decreaces. If you have noticed, the area of a riser (not bow) is
roughly the same as your bow arm (ignoring holes) thus the force
exerted by a breeze on your arm will be noticably less than that
exerted on the riser as it is so far away from the pivot point of your
shoulder. 
        As it is awkward to start reducing the effective area of your
arm then the only thing you can reduce the area of is the bow handle.
From the reasons outlined above, then the difference between solid
handles and 'holey' ones can be appreciable, especially when shooting
in light winds (not Gales) I have shot solid handles and 'holey'
handles in domestic and international competitions in field and
target, and believe me when i say, it does make a difference!!

        Oh sorry i didnt mean to get that carried away, if anyone
wants to shout at me or argue about the above please mail me.

Tim Mundon....

------------------------------------------------------------------------------

From: Hywel Owen <h.owen@dl.ac.uk>
Subject: Re: Holes in your bow - Riser Strength
Date: Thu, 01 Feb 1996 09:28:13 +0000

John Dickson wrote:
>  Weight doesn't seem so important in the eyes
> of the buyer these days (unless you shoot an Eolla or a Carbofast
> Diamond Star), the Radian and the Greenhorn Diamond are both heavier
> than the Stylist (so I'm told?)
> 

You're right, I don't think the weight of a riser is considered as 
important these days. Once 'fat' rod stabilisers came into fashion 
(remember, AGF were making fat short rods for years before the 
others !), people realised they didn't want lots of weight bouncing 
around at the end of long, wobbly stabilisers, so they took it all 
off. Now everyone seems to be using less stabilisation, they get the 
stability on release they want by using a nice, heavy riser!

What do I use? A heavy (original) Stylist handle, Eddy Robinson 
'original' diameter parallel rods (3/4" thick). These are set in the 
classic 'US-Style' arrangement: - 24" long rod, 4" extender, V-Bar 
with 2 x 7" short rods 30deg out, slightly below centre, and no top 
rod. I don't need a top rod because the handle is well balanced and 
the short rods don't hang too far behind the grip.

Why am I telling you this? Well, the difference in weight between 
most metal risers is only about 200g. Weigh a top rod - you'll find 
that most fat rods weigh more than 200g. So, if you've got a heavy 
riser, put a V-Bar extender on (but you already use one, don't you 
;> ), shorten your short rods, and forget the top rod! Hey presto! 
You've got a setup that in total weighs less than someone else's who 
uses a top rod but has a lighter riser. This may be a workable 
solution if you don't like the weight of your setup.

Moral 1: It's not the weight of your riser which matters, it's the 
total weight of your setup.

Moral 2: Heavy risers are not a problem.


Hywel Owen

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From: j.m.muller@student.utwente.nl (Marcelo Muller)
Subject: Re: Holes in your bow - Riser Strength
Date: Thu, 1 Feb 1996 12:20:22 UNDEFINED

Hywel Owen <h.owen@dl.ac.uk> writes:

>John Dickson wrote:
>>  Weight doesn't seem so important in the eyes
>> of the buyer these days (unless you shoot an Eolla or a Carbofast
>> Diamond Star), the Radian and the Greenhorn Diamond are both heavier
>> than the Stylist (so I'm told?)
>> 

>You're right, I don't think the weight of a riser is considered as 
>important these days.

<Snip AGF, fat and wobbly stabilisers >

<Snip again: Hywel's setup>

>Why am I telling you this? Well, the difference in weight between 
>most metal risers is only about 200g. Weigh a top rod - you'll find 
>that most fat rods weigh more than 200g. So, if you've got a heavy 
>riser, put a V-Bar extender on (but you already use one, don't you 
>;> ), shorten your short rods, and forget the top rod! Hey presto! 
>You've got a setup that in total weighs less than someone else's who 
>uses a top rod but has a lighter riser. This may be a workable 
>solution if you don't like the weight of your setup.

>Moral 1: It's not the weight of your riser which matters, it's the 
>total weight of your setup.

Agreed, an archer is not a weightlifter.

>Moral 2: Heavy risers are not a problem.

Here I must disagree :-)

You mention that your setup weight matters. Well, if your riser is heavy, it 
will largely dominate the total weight. If you do not feel comfortable with 
the balance or feel of the bow, it gets harder to balance the bow without 
adding too much weight to it. 

As stabilisation is a very personal matter and will vary from person to 
person, I think you are better off with a light riser. In that way you have 
control over how the weight is distributed and can taylor the balance to 
your specific needs.

Low weight was, to me, the only reason one would buy a carbon riser. You had 
more room for experiment :-). As I haven't heard or shot the Carbofast 
Emerald Star, I do not know how the claim of better damping comes into this 
picture now. When I find out, I will let you know.

Heavy risers are an advantage for barebow field archers, though. As they are 
not allowed to use stabilisers, a heavy riser is more stable. Carbofast (and I 
think Greenhorn) have a special version of their machined handle for these 
purposes. Don't know what the rules say about this, I heard rumours people 
were not to happy.... Anyone?


Of course, everything with a :-)

Marcelo

------------------------------------------------------------------------------

From: Hywel Owen <h.owen@dl.ac.uk>
Subject: Re: Holes in your bow
Date: Thu, 01 Feb 1996 11:43:33 +0000

John Jones wrote:
> >
> >
> Isn't it really to reduce weight?  Though there was a lot of
> cobblers in the Radian advertisements about letting the
> vibration out ...
> 
I'm beginning to incline with John Dickson (see other posting) that 
holes are only a fashion item. If you're machining the riser anyway, 
it doesn't take much extra time to put some holes in, so why not?

They'll probably think of something else that's sexy soon enough...

Hywel
------------------------------------------------------------------------------

From: Jim Buch <jbuch@earthlink.net>
Subject: Re: Holes in your bow
Date: 1 Feb 1996 14:28:43 GMT


I'm all ears and eyes.  I am ready,willing and able to be enlightened.

dna1000@cus.cam.ac.uk (David Allsopp) wrote:
>In article <Claes.Colmeus.11.000A17DB@farm.lu.se>,
>Claes Colmeus <Claes.Colmeus@farm.lu.se> wrote:
>

>[Note for sci.materials readers - this thread concerns the milling/drilling
>of holes in the alloy centre section (riser) of archery bows]
>
>>>> Oh -- holes also do a fourth thing: they make the riser weaker...
>
>>Not necessarily so. In fact, correctly shaped and placed holes can 
>>actually improve strength by distributing stress concentrations. 
>
>Are you sure about this? Holes *create* stress concentrations. The only
>case I can think of where a hole improves the stress distribution is if
>it is drilled at the apex of a crack or notch, thereby blunting the notch.
>(eg drilling holes at each end of a crack in a perspex sheet to stop the
>crack growing)
>
>Have you ever 
>>tried to tear perforated  paper? Does it ever part in the perforation? 
>
------
>It can 
>>be shown, even in theory, that a reasonable amount of perforation, especially 
>>with round holes, will improve the strength of any sheet material. 
>------------
>Do you have any references/calculations for this effect? 
>David.

-- 
James D Buch  
-------------------------------------------------------------------------------
From: jdickson@festival.ed.ac.uk (John Dickson)
Subject: Re: Holes in your bow - Riser Strength
Date: 2 Feb 1996 11:50:46 GMT

Hywel Owen <h.owen@dl.ac.uk> writes:

>You're right, I don't think the weight of a riser is considered as 
>important these days. Once 'fat' rod stabilisers came into fashion 
>(remember, AGF were making fat short rods for years before the 
>others !), people realised they didn't want lots of weight bouncing 
>around at the end of long, wobbly stabilisers, so they took it all 
>off. Now everyone seems to be using less stabilisation, they get the 
>stability on release they want by using a nice, heavy riser!

Ah, but AGF rods were fat and wibbly! Very wibbly in fact. Wibble
wibble. They did look good tho' (I had a full set). To be honest the AGF
rods are more like plastic than carbon (splitting hairs) but they work
if you like that kind of thing.

>What do I use? A heavy (original) Stylist handle, Eddy Robinson 
>'original' diameter parallel rods (3/4" thick). These are set in the 
>classic 'US-Style' arrangement: - 24" long rod, 4" extender, V-Bar 
>with 2 x 7" short rods 30deg out, slightly below centre, and no top 
>rod. I don't need a top rod because the handle is well balanced and 
>the short rods don't hang too far behind the grip.

Something that has to be mentioned is that the stabiliser setup you
prefer will depend on the bow geometry/balance at full draw, draw weight
and length will affect this. In my experience longer draw archers tend
to prefer the feel of bows with top rods (Hallard, Evans, Myself ;-)

Although this may be coincidence. I can shoot fine, and am stable
without the top rod but adding it improves the feel at full draw and in
follow through.

<Snip ...the soloution>

I tried 8" twins a while back, didn't like them, prefered 10". I did
like them on the end of an 8" extender with no top rod but personally I
can't control the bow with an extender that long...it's weird, try it!

>Moral 1: It's not the weight of your riser which matters, it's the 
>total weight of your setup.

Indeed, although within reasons, that doesn't matter either.

>Moral 2: Heavy risers are not a problem.

As long as you can lift them ;-) I wouldn't like to shoot a bow over
1200g, I think that the weight would become an issue (if shooting
Olympic class of course). Having said that Goran Berendjal (spl?!?) of
Sweeden shoots a Stylist with top rod and swing bar which must be fairly
hefty but is no problem to him. So over 1200g would become a problem for
ME ;-)

                                Stretch
--
John Dickson,(aka Stretch) 

------------------------------------------------------------------------------

From: jdickson@festival.ed.ac.uk (John Dickson)
Subject: Re: Holes in your bow
Date: 5 Feb 1996 10:44:39 GMT

Hywel Owen <h.owen@dl.ac.uk> writes:

>I'm beginning to incline with John Dickson (see other posting) that 
>holes are only a fashion item. If you're machining the riser anyway, 
>it doesn't take much extra time to put some holes in, so why not?

Don't misquote me... I said partly a fashion statement, primarily holes
increase the strength to weight ratio of the bow. I do not however agree
with the "lightest is best" philosophy.

Actually putting holes in the bow does take quite a lot of extra time
and cost (CNC programming etc)

>They'll probably think of something else that's sexy soon enough...

Well Hoyt did try with the WILD THINGS...eek, although the Splatter job
on the Avalon is cooler than the Psycedelic Camoflage on the Radian ;-)

On the subject on wind and holes etc, I would have thought that with the
holes being relatively small, if the wind passed thro them you'd get
turbulence generated around the holes (since they don't have an
aerodynamic profile) and hence de-stabilise your bow in the wind ;-)

                                Stretch

PS If the wind goes through the holes in my bow, can I have holes in my
arrows too?

PPS Anyone taking themselves too seriously will be sniggered at!
--
John Dickson,(aka Stretch) 





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