Breakthrough BBI

[Almostpighunter]

This is a milestone bow for me as I finally was able to break the 170fps arrow speed (with my heavy arrows) that had been eluding me. I know this may not be much of a feat for many of the people on this forum, but for me it was a big deal!

The bow is a 64" (62"n2n) bamboo backed ipe 67#@28". I tried to keep the limbs as narrow as possible throughout the length of the bow and made the tips into knife edges on both the belly and back. The idea was to have the minimal tips slice through the air and the narrow limbs assist in doing the same. I ended up shooting my 515g arrow (total weight including 150g field tip) @ 174fps. Huzzah!!!

[JW_Halverson]

Oh man!  Me want, me want!

[Keenan]

Congratulations! That is a great looking bow. Tiller looks right on and I always love the contrast with BBI bows. That is an impressive speed with that weight arrow. Well done

[Badger]

  Nice job on that bow, don't let the chrono speeds get to you. Release and drawing tecniques proabably have more to do with it than the bow. The bow you are shooting their could likley hit over 200 fps with an active release drawn fully to 28".

[Justin Snyder]

Good looking bow. I have to admit I would be scared that the boo was going to lift where you tapered the boo on the tips like that. It is like violating a ring on a wood backing.

[blackhawk]

Nice looking bow and im sure it shoots where you look,which is the most important thing  ....according to your chrono reading at only 7.7 gpp that's just still an average fps. Try breaking that barrier with a 10gpp weight arrow if your into trying to build high performance bows. But as steve mentions chrono readings can be misreading as everyone shoots differently and it can affect your numbers. And speed doesn't mean everything,but it sure helps

[TurtleCreek]

  Great job!

[Del the cat]

Excellent, that's an impressive speed.
Great looking bow too.
I'd be a tad worried by the notch in the back of the bamboo, but I've not used boo (yet).
I'd have done a real short skinny horn overlay, just a sliver to take the notch.
Faster than any of mine so it looks good to me.
Del
BTW, I only recently got a set of grain scales and I was surprised how heavy a string is. Mind I found out they don't shoot very well without a string

[medicinewheel]

This is a really nice bow!

[mikekeswick]

Well done with your achievement, it's very satisfying to set a goal and achieve it when you use nothing but your skill.
I also was a little worried when I saw your tips (not the width), cutting through the back of the boo to make the groove is risky. Next time try putting an overlay on and cut the groove into that. I think you could lose a bit more weight out past the nocks as well, have say only 1/2 inch past instead of a full inch.
Del - make some 4 strand fastflight strings.....still strong enough for a 65lber....mind they sing a bit

[dbb]

Nice Bow!
At that speed im sure its delivering the message with authority

/Mikael

[Almostpighunter]

Thanks for all the nice comments guys! I understand the nock fears  but the idea there was to take the deep groove of the bamboo notch down almost to the Ipe so, i thought, the forces would be acting more on the hard Ipe than the notched bamboo and keep it from lifting. I could be wrong, but in the end only time and shooting will tell.

@ Blackhawk: sorry bud, I don't understand your measurement numbers. Is gpp grains per pound? How are these numbers achieved? Honestly my only concern was in trying to get the fps up with my arrows, so maybe this means my other bows are sub standard in performance? I don't know...but then again I just carve the wood. I haven't really gotten into the engineering and physics at this point.

[coaster500]

Super job, that is one slick shooter and I would not want to be in front of that arrow  

Congrats!!!


515 divided by 67#s is about 7.7 grains per pound of draw weight.... to be at 10 grains per pound you would have to shoot a 670 grain arrow...  hope this helps...

[Scowler]

Congratulations!  Its always good to achieve a goal.  Whats next...180fps?

[RyanY]

I have to agree with blackhawk when he says that 174 fps is probably average for a bow of this weight with those arrows. Many people measure speed using arrows that are 10 grains per pound of draw weight and studies have shown that 174 fps is good performance for a laminated bow using 10gpp arrows. This is also why badger has said that you could achieve over 200fps with those arrows and that bow. Still a beautiful bow by any standards and as long as you hit your goal that's what's important.