A mass question

[DC]

I'm looking at two of my recent bows. They are similar in design, roughly the same dimensions. The first is the Maple backed Yew I posted a while back, 40#@27" and weighs 420 grams. The second is an Ocean Spray I just finished also 40#@27" but it weighs 620 grams. The yew shoots 190 fps and the OS shoots 170 fps. If I try another OS but make it substantially narrower is there a chance I could make a 40# bow that weighs close to the 420grams of the Yew? Yews SG is around .65 and Os is around 1.2.

[Badger]

  Mass might not account for the bulk of the difference in performance. Do they have similar FDC's. If so does the OS have a higher moisture content? Did it take more set? The 190 you got is highly unusual for that profile. The 170 is slightly on the low side. The Osage/boo bow is right at the expected mass while the OS bow is on the heavy side, it should be about 10% more than the osage. To me it sounds like the wood might be a bit higher in moisture.

[DC]

It's Yew not Osage. Does that change your thinking much? Or were you thinking Yew and writing Osage ? I haven't cut any staves for quite while so the OS should be dry but there is a chance it may be wet yet. My record keeping isn't up to much.
What I'm wondering though, is there a point where a dense wood just can't get as light because of lateral stability? It may work for a longbow design but not for a deflex/ reflex.

[bradsmith2010]

give it a try,, side tiller to you feel like it might take set,, and see what it does,, you might not get all the way to the other mass but you should be able to move that direction some and get it shooting a bit harder,, 

[Badger]

It's Yew not Osage. Does that change your thinking much? Or were you thinking Yew and writing Osage ? I haven't cut any staves for quite while so the OS should be dry but there is a chance it may be wet yet. My record keeping isn't up to much.
What I'm wondering though, is there a point where a dense wood just can't get as light because of lateral stability? It may work for a longbow design but not for a deflex/ reflex.

  One of the issues I deal with when using ipe to make ELBs is that it is almost too dense to get the profile I need on 50# and lighter bows, I can usually just keep rounding till I make it but it really want to be narrower and thinner. I don't like to go below about 7/8 wide if I can avoid it.

[DC]

give it a try,, side tiller to you feel like it might take set,, and see what it does,, you might not get all the way to the other mass but you should be able to move that direction some and get it shooting a bit harder,, 

[DC]

give it a try,, side tiller to you feel like it might take set,, and see what it does,, you might not get all the way to the other mass but you should be able to move that direction some and get it shooting a bit harder,, 

I'm steaming it as we type

[bradsmith2010]

worth a try,, interesting to see what it does,, 

[DC]

I have to apologise. I was comparing the Yew at 28" with the OS at 26". I retested both and the Yew shot 185 with a 400 grain arrow and the OS shot 181 with the same arrow.
FDC's
            Yew           Os
8"          3#             9#
10         10             15
12         15             19
14         19.5          23
16         23.5          26
18         26.5          29
20         30             32
22         33             35
24         36             38
26         40             40
28         44             43
          185fps       181fps

The Yew has short static recurves and the OS is just reflexed but the OS has about an inch more reflex total.