BOW GEOMETRY/DESIGN ADDRESSED

[Len in Maryland]

I was asked to get involved in a discussionon another thread/forumconcerning bow geometry and forgiveness, so bear with me. Please read what I'm about to type carefully before you start swinging.

Brace height, IMPO, is highly overrated. Manufacturers have for years achieved speed through reflex. Reflex, when compared to deflex, is very unforgiving - EXCEPT IN THE HANDS OF AN EXCELLENT SHOOTER. The problem with reflex is that it takes moretime to settle in when first coming to full draw when compared to a deflex riser. Couple this with a short ata bow in the hands of a longer DL shooter and you complicate the problems.

Brace height forgives shooters who want to 'stretch out' - draw length that is. Tournament shooters, who have to shoot longer distances with lower poundage bows, desire longer draw lengths to achieve more speed with lesser poundage. Don't get mad or angry, it's a necessary evil that has been developed over time. Remember, they used to only have round wheels. Cams, and especially smoother drawing fast cams, have aided their needs. More and more tournament people are now using cams over round wheels these days. The proof is in the availability of true round wheels any more.

Wrist straps were the developement of tournament shooters. The longer draw lengths meant putting the arm in 'harm's way' and the sling allowed them to throw out the elbow and leave the hand open. In order to keep the bow from jumping out of the hand, a sling was developed. The first slings were actually a rope placed around the riser. Today many of them use a finger sling which is an extension of what I teachwhich isusing only the forefinger and thumb.

All this was done to keep from hitting the arm/clothing. The hunter has more of an issue because his arm diameter/radius increases as heavier clothing is added. I hear many of my fellow hunters say that the arm guard keeps them from hitting their arm/clothing. BUT, the string, if it touches anything before the arrow is launched, will affect arrow flight. The string can't hit anything until the arrow leaves it. String snubbers, if properly installed, are the exception.

Now that we've defined some of these issues as I see them, let's get tothe world of parallel limb technology. Parallel limbs, coupled with aggressive cams, have given us many assets. First they automatically move the brace height out further. Their movement moreso in opposite directions results in what can be dubbed vibration/noise cancellation. The longer risers necessary with this technology provides more vibration/noise cancellation because there is more mass to them. Strategic riser design and placement of rubber dampening devices reduce the 'tuning fork' effect.

The increase in brace height, coupled with the reflex risers, have given us a whole new world of shooting. What was once tabooto many of us 'old timers' should now be reevaluated. While I still think that ata shouldfit theDL of the shooter ("bigger bows for bigger guys, and smaller bows for smaller guys"[ladies, please excuse the chauvinism]), I find that parallel limb bows reduce that number. In other words, I personally find that 2-3" in atareduction is acceptable inPLT over older traditional designs.

To conclude, the Vulcanstyle bow (in the hands of anEXCELLENT shooter)will shoot just as accurately as the Vectrix style bow provided you have time for it to 'settle in.' Now you have to determine what I mean by EXCELLENCE in shooting.

[gibblet]

pearls

[98Redline]

Len....you seem to have hit the nail squarely on the head.

Since shooting a couple of parallel limb bows and ultimately buying one for hunting, I have felt that this design "feels" like a longer bow than it's ATA would give it credit for being. I think what you are referring to, in physics terms, is called "moment of inertia" which is essentially a resistance to rotation about an axis. In essence the longer ATA bows have had a higher moment of inertia due to....well their longer ATA. Given 2 bows of the same design, the longer one was normally the more stable one.

Enter the parallel limb designs with more weight out on the end of the riser and you have a bow with significantly less ATA, but the same moment of inertia. In the shooters hands, you get that "stability" that was previously attained only by going with a longer ATA bow.

It is very similar in concept to adding weight out at the end of a stabilizer. The more weight, the harder it is to get moving and ultimately the more stable your shot. You could get the same feel from a lighter stabilizer, but it would have to be significantly longer to have the same effect.

[PABowhntr]

Nice post Len. Thank you for taking the time to share your thoughts.

[mobow]

Len, I learned more from this post than most I've ever read. You put very elegantly into words something I've been saying for quite a while, which basically is that times have changed and what was once "rule of thumb" isnt' the case anymore.

Anyway, thank you sir, and how far are you from Canton OH BTW?

[MonsterBuckDreams]

You can't even get this kind of info at the best of proshops because they don't have the time to get into the intimate details like this. Truly invaluable. I feel like I just got my car fixed free of charge by a master technician. THANK YOU SIR!

[Dubbya]

You know that whenever the blue font comes out, that whatever it says is going to very valuable. Thanks Len!

[drhoyt]

thanks for the good post

[trestand]

Well Len,Thats basically what I was talking to you about at your shop on Sunday.You know me well enough to know what I'm looking for.I'm sure we will come up with the right combination as we (you),did with my Vetech.
.....Bob

[jsasker]

You can't get this kind of information at most "pro" shops,BECAUSE THEY DON'T HAVE IT--PERIOD!Just because they are a pro shop does not mean they have all the answers--you're lucky if you can find a shop that will give you what you pay for.[:-]