fastest selfbow?

[Badger]

Karl, what speed are you trying to reach at what arrow weight per pound. We now know for certain that 200 fps is possible. Looking at Marks bow it is very similar to a longbow but has the static recurves. I think maintaining high efficiency is more important than looking for more energy storage for optimum speed. Both Longbows and recurves have crossed the 190 mark. Steve

[Marc St Louis]

Actually David the recurves could stand to lose a bit of useless bulk.

I don't remember exactly what the draw weight was but it was about 55#.  The bow was tillered to 27"

[DCM]

"Actually David the recurves could stand to lose a bit of useless bulk."

LOL.  I suppose it's a matter of perspective.  I don't disagree.  I just lack the cojones I reckon.

[Karl-Heinz]

We now know for certain that 200 fps is possible.

lol Why has no one a 200 fps bow with 10grain/lb ? 190 is not 200, it is more or less like the sonic barrier, close is not through.


K-H

[Badger]

Karl, myself and a few other guys I know of have actually hit 194 fps, I know from experience that if I were to have lightened the string, loosened the arrow nock and cleaned up the arrow shelf I could have squeaked out 198 fps. Thats close enough to tell me it's possible. Modern longbows are now hitting 200 fps, recurves have just scratched above 192 I believe. One gentleman with recurves has reported a 200 fps but the bow broke before it could be verified.

[Karl-Heinz]

I know from experience that if I were to have lightened the string

3 grain stringweight / lb !!

Regards

K-H

[Justin Snyder]

Steve, are you going to the flight shoot this year?  What are the dates? Justin

[Badger]

Justin, I won't be able to make it this year it looks. The dates are going to be weekend of sept 8th, Just a long shot I might be able to swing it but I doubt it. Steve

[scp]

We now know for certain that 200 fps is possible.

lol Why has no one a 200 fps bow with 10grain/lb ? 190 is not 200, it is more or less like the sonic barrier, close is not through.

How about now? Still no 200 fps with 10gr/lb selfbow?

[Badger]

  As far as I know no one has surpassed it yet. Only a few modern bows using carbon fiber and skinny fast flite strings have surpassed it. If anyone ever does surpass it it would be questionable and need to be verified very carefully. I still think it is possible if everything came together. Some work I did on no set tillering a few years ago does imply that wood can be nearly as efficient as fiberglass or even carbon fiber before it starts to break down. If best designs were used with best woods and flawless tillering it might happen.

[IndianGuy]

I made a 39# @27 " static recurve from Osage that got me a lil over 160 fps with a 550 grain arrow, surprised me and the certified archery instructor who let me use his chrono, I dint have any lighter arrows at the time..would have been interesting to see with a lite arrow.

I have got 160's from 48" sinew backed osage bows many times.
The best I've ever got was 206 fps with a Korean composit bow with a carbon arrow..but never a self bow.
E

[huisme]

I made a modern holmegaarde style from black locust, very light heat treatment after tillering, for my best friend who took it to a range and her first classes and wowed the instructor and pros with its speed. No numbers as of yet, I know it's 35#@26", but ill have to get fps next time I'm up her way.

I'm curious to hear what Blackhawk has achieved with his mollegabets.

[redhawk55]

Love that speed- topic forever!

I` ve experienced short bows shot with light arrows to be the highlights in this case.
For to match the 10GPP- challenge just scale down like Woodbear has stated it in the PALEOPLANET: " Being a guy with 25" draw, I find that bow 10gpp performance with a standard 28" draw, does not really tell me what performance a particular design will give me at 25", it always requires some translation. The translation comes in the form of the modified formula. The formula does not simply divide 10gpp by 28". I scale the 10gpp rule by the ratio of my draw to the standard 28" draw. So I expect that my 25" draw bow with a 10x25/28 = 8.9gpp arrow will give the same speed as a same design 28" draw bow with a 10gpp arrow.

For example, a 54" long, 43# at 25" bow will be tested with 10x25/28 = 8.9gpp arrow (383 grain arrow), and should give the same arrow speed as an "equivalent" design 62.6" long, 43# at 28" bow at 10gpp (430grain arrow). This will give a good idea of how a small version of a design will perform if enlarged to standard draw.

I hope this clarifies the rationale and use of the modified grains per pound guide line."

Or here: "Arrow weight is 280grs., drawweight is 40= 7gpp. For comparison with a 28" draw I would need 10x 23/28= 8.21gpp. So I had to use a 328grs. arrow? 328/40=8.2?"

The topic is here: http://paleoplanet69529.yuku.com/topic/55268/10-grains-per-pound?page=1

So there is much more space for experiments!

I guess a lot of selfbowyers are trying to break the 200f/s, this is at least a great guideline to increase  performance.
But the weakest spot seem to bemuch more the arrow than the bow.
I`ve recently succeded in making barrelled wooden shafts( 23" in length, max. thickness is 7mm or about 1/8", 283grs.) with a deflection of 0.45 - 0.59( 100+ lbs spine), but have not yet shooting them.

Michael

[sleek]

Hi redhawk. Good to see you. Glad you brought the link in. I get frustrated with the 10gpp view when folks dont account for draw length. Woodbear came up with a brilliant solution for that.