I was reading an article in this month's Bowhunting concerning the + and -'s of shooting speed bows. He cover many of the same old arguments in the speed debate, but then he mentioned something I've never heard before. He stated that faster arrows are more susceptible to planing with a fixed blade head than slower arrows. He stated mechanical's are less apt to suffer this effect, as are the lower profile fixed heads. He states, "Even with today's small profile, fixed-blade heads, most experts recommend a maximum arrow speed of 260-270fps. Beyond that, broadhead planing becomes problematic for all but the very best archers." So am I one of the very best archers? :d In all seriousness, I haven't hear mention of this from any of the guys on here or HNI over the years, and I haven't experienced this with my 101st shooting well over these speeds. I would assume that as long as you're spined correctly, and you've tuned correctly, and of course you have adequate stabilization out back, BHs should fly just fine no matter what speed. Correct?
I'll say you are correct. Tuned and matched tuned is tuned. Although I feel the author is correct under less than ideal conditions which is usually the majority of archers, speed isn't the same issue when everything is perfect or very near. Great broadhead flight, beyond a tuned bow is the spinning of an arrow, the faster/quicker it spins the faster/quicker it will stabilize.
Jeff, in theory I understand the concept. My questioning was how MUCH it truly is an issue assuming you are properly tuned, spined, and have good BH alignment. I had never heard those FPS limitation numbers before from anyone, so that's why I was curious. I personally have never heard of anyone experiencing issues shooting fixed blade heads in excess of 270fps with serious issues.
This is kind of related to the fletching spin thread. IMO the fletching is designed to correct the plane created by the fixed broadhead. The author is absolutely right, speed multiplies the deviation caused by the steering blades aka "front-rudders". So, expandable heads should be used if the hunter is shooting over 305 fps and the target is over 30 to 35 yards. With any less speed or yardage, the fixed heads "shouldn't" deviate enough to miss the killzone. (My oppinion is based on the killzone of a 100 lb. deer not a rat or mouse! Again, this is just my oppinion.)
I'm shooting fixed heads over 270fps. The issues I was having (as mentioned in my other thread) are not related to BH/speed. I would imagine taking .25" off my current arrow length or dropping a few lbs would solve everything. As for the perfectly tuned, if your nock height is set, bareshaft tuned, walkback tuned and/or group/french tuned, and finally BH tuned, THEN (and that's what I'm getting at, only THEN) I can't see there being an issue. Heck, everyone was jumping on this "don't shoot a mechanical as bandaid to tuning issues" bandwagon not more than a few years back, and now I'm getting the impression that even a well tuned bow (no, not just sighted in) isn't going to shoot a fixed blade head as well, so you mind as well throw that mechanical back on again. I will admit I do agree with the physics behind it. It's pretty obvious, BUT the recommendation made by the author in terms of speed limitations was news to me. I'm not trying to start an argument, but where did those numbers come from? The author mentioned speeds much slower than that. In fact, with many of today's bows, anyone shooting a moderate arrow weight and normal DL are probably pushing past the 270fps mark. 305, probably not as much, but it's becoming much more common place. I wonder how many of today's archers shooting these compounds are shooting fixed vs mechanical? Again, I'm not trying to start arguments, I just was curious about the numbers being referenced in the article and the recommendations.
Lean out and around a tree and get some hand torque on the grip on a 30 yard shot and it is a huge problem,especially if there is a little breeze that day. You might not notice it in the back yard but in the field is where these things show up.
Back in the 90's I encountered this very thing and found that 270 was about the max number. However, a lot of things have changed since then. In order to get an aluminum shaft light enough to be shot at 270 fps back then it had to be shot off an overdraw. That in itself was enough to throw arrows all over the place regardless of the speed. It may not have been that the actual speed limit of 270 was the problem. What may have been the problem is what it took to reach that speed caused too much issue in good tuning and proper form to be able to shoot a fixed blade head above that speed. Sometimes things aren't what they appear but I still believe that rigs are more forgiving at slower speeds since the arrow has more air time for the fletchings to correct problems in flight. The faster the rig, the tighter the tuning has to be and the better the archer. For the critters I hunt I want to hit them with a freight train at moderate speeds rather than miss them, deflect off or not penetrate with a bullet train. Stuff happens and while my form may be near perfect on the range, I know it isn't in the field. I'll stick with my 560 grain arrows at 255 fps.
Another great post by KA. Nice. He is exactly right, the faster the arrow, the more "tuned" it must. I'll give you an example when I went elk hunting. The setup, a Beman Trophy Hunter 70/90 with outsert and 100 grain 3 blade Muzzy, roughtly 400 grains, 285 fps. When we left for WY we were 12 ringing a McKenzie elk out to 75 yards. We could not shoot broadheads at the same target in fear of damaging arrows. That said, when we reached out destination and higher elevations, both our bows had to be tweaked as well as the sights. We no longer were on! I question if indeed it was the thinner air? Did we pick up some speed? The thinner air showed us some flaws. ? I believe like KA that a heavier, slower arrow would not have had the same issue. We got things dialed and they were still good when we got home. What changed?
KA and Rob, thanks. That makes perfect sense. I don't remember much about older compound technology (I'm a new guy to all of this :D), but I could see where modifying the bow setup to obtain the 270fps Winke mentioned could cause the planing effect to be magnified. Good stuff, guys, thanks for the education.
Back in the 90's we had to "cheat" to achieve today's speeds. That had to come at a price. Today, we almost have to "dumd down" our bows to get a slower desirable speed. Take my 06 Alley. With the same ACC I shot in the 90's I was over 305 fps. A competition bow I shot in 96 I had to tweak every way possible to barely reach 300 fps. Again, it came at a price. The Alley was grouping fixed blade heads out to 50 yards leaving the arrow at 305 fps.
MGH_PA, in reference to your question about the numbers I came up with.....They are just about the average speed of the (hunting) bows that I am personally surrounded by. My friends and I shoot some fast bows, and we have all chatted about this before. Those numbers just seem to be "about right" to this certain group of people. I can understand your reason for asking!
This brings up a good point. If you have achieved the higher speed through reduction in arrow weight or some other shortcut, then you would be more susceptible to broadhead planing. If the higher speed is attained through a more efficient (and tuned) bow, then the increased speed should not be as great a factor.
in my experience I've never been able to get a fixed blade to fly quite as good as a mechanical. Which does make sense to me with the speed some of these bows are shooting. I believe a mechanical fly's better with your faster bows than fixed blades do, thats just my experience because i've never been able to get a fixed blade to fly all that great outta my bows i've had(which all have shot over 270 fps)
The guy in the article probably didn't have his broadheads aligned with his fletchings. (Sorry I couldn't resist it.)
