Trad Talk Forums banner
1 - 20 of 22 Posts

·
Registered
Joined
·
554 Posts
Discussion Starter · #1 ·
I was watching an archer shoot a very nice high-end ILF bow and noticed a great amount of limb tip flutter after the shot. She was shooting with tab, using the Mediterranean release. Her form overall looked spot on; nothing stood out hinting at heeling the grip. Any ideas as to what would cause the limb tips to so violently vibrate back & forth?
 

·
Registered
Joined
·
1,815 Posts
Limb design. I get some with Morrison Max 6 ILF and more with my Border Covert Hunter.
 
  • Like
Reactions: CD

·
Registered
Joined
·
2,359 Posts
Bill, on the money with that. I saw a YouTube video comparing the two. Morrison has quite a bit less than Border.

Remember the thread on Backwoods Composites? The OP went off on Border because of it.

Bowmania
 

·
Registered
Joined
·
554 Posts
Discussion Starter · #4 ·
If it's only because of limb design, then is this flutter issue entirely moot, and of no consequence to arrow flight? Am wondering because at first I thought the flutter was from tiller being horribly off.
 

·
Registered
Joined
·
6,497 Posts
We have to remember that Borders main (if not "only") focus was innovation with an emphasis on performance to the point that they actually achieved their goal of "Let-off" which they rapidly abandoned once they realized that that let-off came at a cost to performance and I only mention the preceding to remind folks of just how radical their goals and achievements were....that said?....those big hooks come home to what is very low brace height as well as very low static string tension which means that "low string tension" is doing very little to quell any residual vibes/energy left in the limbs.
 

·
Registered
Joined
·
6,497 Posts
PS: almost forgot....another thing that adds to the mix of limb tip flutter with SR type limbs is the extraordinary amount of "Limb Tip Trave" meaning?....if you observe conventional limb tips and how far they travel from static to fully drawn as compared to SR limb tips?....(pending bow length)....SR Limb Tips travel 2-3 X's further than conventional limb tips so when you drop the string on conventional limbs?...the tips only travers through about 6-8"s of motion before coming to closed position while SR limb tips will cut through upwards of 12-16"s of motion as those hooks wrap up 2-3X's the amount of string in the elongated string grooves so all that limb mass?...traveling that greatly increased distance?...and then coming home to both low BH and low static string tension?...='s greatly amplified limb flutter.
 

·
Registered
Joined
·
6,497 Posts
AND the reason they have high performance - the arrow is on the string longer.

Bowmania
Todd?...love ya like a Brother but if that were true?...there''d be a ton of Longbows out there smoking recurves...but there's not....now?...does the low BH "help" increase performance?....yes....a little bit...but it is definitely not..."the reason they have high performance"...and the reasons they have high performance are many from how they begin storing large amounts of energy in the front end of the DFC to the low mass weight of the "Glass-less" limbs and ultimately?...the tremendous amount of energy stored as all that opening up of the big hooks takes place and leverages the working mid-limb.

In working with Steve Jewett on the development of his Scythian model we actually went the other way where the front end of the draw cycle is rather soft and
easy starting" (so to speak) and despite that characteristic?...the Scythian still sports very respectable performance where I would rate it squarely between a recurve and a longbow yet it draws with all the silky smoothness of what feels like a well sorted 68" longbow in a 60-62" package so what I'm saying is that last little bit of what is very low string tension doesn't contribute a whole lot to the overall performance.

Plant Bow Tripod Shotgun Tree


It's that initial kick in the azz when you drop the string and how well the limbs sustain the energy rather than experiencing a rapid decay of energy.

I know things. ;) LOL!
 

·
Registered
Joined
·
6,427 Posts
SRs store more energy but are at best similar efficiency to a standard geometry limb of the same mass. So unless you increase arrow weight well past what any competitive archer would use the limbs release the arrow with a lot of energy remaining. Add in sub-average vertical stability and temperamental tiller requirements leads to the flapping.
 

·
Registered
Joined
·
406 Posts
My border limbs fluttered like crazy on slow mo. Max 6s not as much but still so
Havnt slow mo videod my longbows yet. Though I dont feel that buzz i got with super curves.
I think I may do so today.
 

·
Premium Member
Joined
·
12,650 Posts
thanks JIM
 

·
Registered
Joined
·
1,815 Posts
As Bill stated earlier, the tips vibrate after the arrow leaves the string
It is the price I am willing to pay for the performance and the draw.
But some shooters mind it more.
 

·
Registered
Joined
·
2,359 Posts
Bill, I can't disagree. BUT all the things you mention ... lead to the arrow being on the string longer. I don't know how a longbow would get into the 'speed conversation'. I don't believe an ACS could beat a static tip Balistik. If you go to ILF set ups and measured a conventional 62 inch bow compared to a SR 62 inch, the SR will be shorter. The limbs will turn over, which keeps the arrow on the string longer.

Jim, that's the video I mentioned, Thanks.

Bronco, I have to tell you I never noticed the 'fluttering'. I had some tuning issues (which Jinks helped me figure out) to start. By the time I had the tuning figured out, I guess I'd become accustom to the feel of the shot. Could also been shoulder pain. Now with a replaced shoulder, I don't think I'll change. For me, measuring back tension in ounces, compared to pounds improved my accuracy too much to go back. Plus being able to have more KE (6 foot/pounds) with 39 pounds than my 50 pound longbow is going to help with recovery on the energy delivered with the new shoulder.

Bowmania
 

·
Registered
Joined
·
2,805 Posts
We have to disproof the video because we don't know the the details. there is a thing call shock load. high performance anything have more of it. there are things to reduce it and things that increase it. putting weight in to the arrow reduce this because more energy is transferred to the arrow. putting weight on the string increase this because more energy is retained in the string, limbs and riser, then transferred into the archer. If you want to stop the twang of the string put a small piece of Velcro on the limb just the contact point extend down half inch. keep the weight off the string. this is the advise i got from the SR builder.
 

·
Registered
Joined
·
69 Posts
Any ideas as to what would cause the limb tips to so violently vibrate back & forth?
Well, putting 40-50 backwards pounds of force on them and then suddenly letting go. In other words, shooting the limbs.

My question is why does it matter? The arrow left the bow, the tips will flutter but it doesn't damage them.
 

·
Registered
Joined
·
554 Posts
Discussion Starter · #19 ·
It's not a question of 'mattering' or not, it's just that I've never seen a bow react like that and I thought it might have something to do with tiller as I posited above. The bow looks like a very nice target recurve, but it isn't a super recurve.
 

·
Registered
Joined
·
6,427 Posts
It matters because it demonstrates instability in nock travel right at release. Specifically if the limbs are flapping in opposition.
 
1 - 20 of 22 Posts
Top