Author Topic: Pyramid vs everything else  (Read 18302 times)

0 Members and 1 Guest are viewing this topic.

Offline bradsmith2010

  • Member
  • Posts: 5,187
Re: Pyramid vs everything else
« Reply #75 on: November 08, 2017, 12:26:14 pm »
this should be a sticky note,, (SH)

Offline Stick Bender

  • Member
  • Posts: 2,003
Re: Pyramid vs everything else
« Reply #76 on: November 08, 2017, 03:12:55 pm »
I guess  this question is in the every thing else category but which front profile launches heavy arrows say 700 grain fastest ? I know the lighter mass bows in the mid & outers have a quick limb return speed but wondering if that apply's as the arrow weight rises ?
If you fear failure you will never Try !

Offline bushboy

  • Member
  • Posts: 2,256
Re: Pyramid vs everything else
« Reply #77 on: November 08, 2017, 03:15:39 pm »
I would put my money on a elb.
Some like motorboats,I like kayaks,some like guns,I like bows,but not the wheelie type.

Offline Badger

  • Member
  • Posts: 8,118
Re: Pyramid vs everything else
« Reply #78 on: November 08, 2017, 03:40:37 pm »
  Heavier arrow weights will tend to favor bows with high energy storage, could be a long elb, or a recurve or a reflexed mid length longbow, they all have pretty high energy storage. Arrow weights mean nothing if you are not talking grains per pound of draw weight. A 700 grain arrow in a 100# bow is a light arrow. I would prefer to see us use grains per pound when talking bow design and efficiency.

Offline DC

  • Member
  • Posts: 10,396
Re: Pyramid vs everything else
« Reply #79 on: November 08, 2017, 03:52:00 pm »
   I have found that a well made bow whose front profile matches its tillered profile will usually shoot right around 170 with a 10 grain arrow drawn 28" and using a clean release. This is with no string follow. Most all of my bows regardless of style end up right around this number. My ELBs used to come in about 5fps lower but when I changed my technique a bit they came right up with the rest of them.

I would also agree. Most of mine come in the 160-165 range but four or five times when the gods were with me I got into the 170's. More good luck than good management but I'll take it anyway ;D ;D

Offline PatM

  • Member
  • Posts: 6,737
Re: Pyramid vs everything else
« Reply #80 on: November 08, 2017, 03:57:49 pm »
According to some the Manchu style bow substantially beats an ELB in casting heavy arrows per draw weight. 
http://www.manchuarchery.org/bows

Offline Stick Bender

  • Member
  • Posts: 2,003
Re: Pyramid vs everything else
« Reply #81 on: November 08, 2017, 04:04:37 pm »
Should have stated 50 lb. 28 draw for comparison .
If you fear failure you will never Try !

Offline Stick Bender

  • Member
  • Posts: 2,003
Re: Pyramid vs everything else
« Reply #82 on: November 08, 2017, 04:10:53 pm »
A well made composite I'm sure would out perform most self bow designs all though it is in the every thing else catagory  :laugh:
If you fear failure you will never Try !

Offline bradsmith2010

  • Member
  • Posts: 5,187
Re: Pyramid vs everything else
« Reply #83 on: November 08, 2017, 04:28:52 pm »
I have heard lots of theories on this,, heavier ggp shooting better from certain types of bows,, some say the wierd bow with 4 limbs,, Penobscot,, shoots heavier arrows better than normal self bows, but again,, I never see any real documentation,,  I think since most of us have no need to shoot heavy arrow not much research or testing is done,,, I am the same way,, I feel like if the bow is shootig great with 10ggp,, I usually dont test it with heavy arrow,, I may hunt with a heavy arrow but just assume since the bow  shoots the lighter arrow well,, it will shoot the heavy arrow well too,, and rarely chorongraph the heavy arrow,, I do hunt with a 700 grain arrow quite often,, from my 50 to 60# self bows,,they fly nice, ,just dont know how fast they are going,, I would guess that with most bows, the bow shooting the best at 10ggp,, will shoot the heavier arrow the best, ,but in archery things can be counter intuitive so I am staying open minded,, (SH)

Offline joachimM

  • Member
  • Posts: 675
  • Good - better - broken
Re: Pyramid vs everything else
« Reply #84 on: November 08, 2017, 04:37:03 pm »
  Heavier arrow weights will tend to favor bows with high energy storage, could be a long elb, or a recurve or a reflexed mid length longbow, they all have pretty high energy storage. Arrow weights mean nothing if you are not talking grains per pound of draw weight. A 700 grain arrow in a 100# bow is a light arrow. I would prefer to see us use grains per pound when talking bow design and efficiency.

I think you probably mean bows with high energy storage and high efficiency.
Straight self bows with ideal tillering have theoretical efficiencies (see table below from Kooi & Bergman 1997, middle column, greek letter čta) that are only marginally bested by working recurves, and higher efficiencies than static recurves. Static recurves have less efficiency because until lift-off of the recurves, the recurves are just dead mass, also during the limb return.

Energy storage, however (provided by the static quality coefficient in the figure below, q), of straight self bows is rather low, and higher in recurves.
The excessive working recurve designed by Clarence Hickman in 1937 (https://www.flickr.com/photos/farflinger/5177069236/), has very high energy storage, but very low efficiency. As a result, it's only marginally faster than the working recurve.  And probably shoots like a dog, because it has massive hand shock.

So all considered, the fastest bow design for heavy arrows (10 gpp) will be working recurves.
I remember some pics from Marc St Louis of bows like this. deflexed out of the fades, gently reflexed in the outer limbs (attached).
A lot like this bow from Alan Case https://www.flickr.com/photos/farflinger/5311429764/in/photostream/
If you scroll up and down in his flickr album, you see the same bow from different angles.

A Manchu bow might beat an ELB, but that's because it has a draw length of 36-38", not 32". Hence it has higher energy storage. Still it will have lower efficiency.

Offline Stick Bender

  • Member
  • Posts: 2,003
Re: Pyramid vs everything else
« Reply #85 on: November 08, 2017, 04:37:39 pm »
I do pretty much the same as you Brad I find my self lately liking heavier & heaver arrows for hunting I'm just curious on designs optimized for heavy arrows or if there is a difference in a pyramid bow shooting them as opposed to other designs !
If you fear failure you will never Try !

Offline PatM

  • Member
  • Posts: 6,737
Re: Pyramid vs everything else
« Reply #86 on: November 08, 2017, 04:52:51 pm »
The  Manchu bow in the linked test was drawn 32"

Offline bushboy

  • Member
  • Posts: 2,256
Re: Pyramid vs everything else
« Reply #87 on: November 08, 2017, 05:25:54 pm »
Again I'm miffed,thought whe were talking about straight stave bows?kinda all over the map.
Some like motorboats,I like kayaks,some like guns,I like bows,but not the wheelie type.

Offline Sir Failalot

  • Member
  • Posts: 22
Re: Pyramid vs everything else
« Reply #88 on: November 08, 2017, 05:43:54 pm »
Can I get a clarification about these attributes?

Energy storage = clear what it is. But more means sending a heavy arrow faster?
Energy efficiency = what? Pulling for example 100# but getting 120# in the arrow? Or is it a smoother draw?

So adding a working recurve to a bow grants more efficiency and energy storage, but the tips need to be wider?
Adding a static recurve to a bow adds a lot of energy storage but reduces energy efficiency, the tipa need to be wider and may cause handshock easyer if not done right?

Wider tips means less energy for the arrow, that's why the benefits of the recurves are that small?

I know it's all theoretical.

Sry if I am annoying anybody with these questions. It's just not easy for a not english speaker that is still green behind his ears to get it right away.
The people at my archery club have no experience with stuff like that so you are my teachers here. )P(

Offline bradsmith2010

  • Member
  • Posts: 5,187
Re: Pyramid vs everything else
« Reply #89 on: November 08, 2017, 05:50:21 pm »
dont worry its not clear to alot of us,, :)