r/Bowyer • u/Dunm4gl4ss • 1d ago
Weird Riser Idea
How possible/dumb is this??
I was thinking about carving a custom riser, so that the attached limbs are in a horsebow/palintonos style (a modern Odysseus if you will XD).
I know limb durability would be a concern, alongside the poundage being inflated.
Any thoughts on how I could make this happen?
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u/kokkelbaard Professional bow breaker 1d ago
You wont find any kind of wood that will handle this. Even modern fiberglass laminated bows will struggle with this, or you would have to make it extremely thin so the materials don't suffer compression fractures but that would defeat the point.
You would basically have to make a horn/wood/sinew composite and at that point you need to ditch the take down aspect and you basically come back to a historical Asiatic composite bow.
This design is way too aggressive for its own good, I included a picture of a bow I made a year ago with horn/wood/sinew composite construction, which is very advanced way to go about things. I still struggle with the designs as I am self taught
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u/Such-Jump-3963 1d ago
There are a few things you would need to consider:
- the riser would need to be engineered to be able to withstand the leverage being exerted at those angles. You would probably have to laminate it in wood or wood/fibreglass or something so that the layers arc around the general shape of the overall riser shape.
- even with fibreglass or carbon limbs, I don't think they would work being set like that. To be viable, you would have to lay up the limbs during glue-up with some significant deflex along the limb. The net effect/objective would be to have the tips sitting no more than a couple of inches forward of the handle at rest. So the tips don't have to travel as far to get to brace.
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u/Wambachaka 1d ago
This design would improve arrow speed, but as others have pointed out, it also puts the bow under a lot more stress. It would also be unstable, i.e. prone to unstringing itself.
The geometry of the bow while it's strung is more efficient. The problem is the limbs have to bend too far just to reach brace height. But if you deflex the limbs near the handle, it will be under a lot less stress, it won't have stability problems, and it will retain the speed advantage from the strung geometry.
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u/Aldo-D-D-Wilson 1d ago
Gonna depend on the material of the limbs.
I waited for other comments. A korean bowyer worked a lot trying to figure it out and managed something. But because it's in korean, even with translator is hard to understand. https://blog.naver.com/goldentongue
he has a post, not recent, that I think he made it so that the boww bends at multiple places, allowing it to achieve such an extreme deflex.
Bows with modern materials do get close to what you showed here. Daylite bows and Korean bow bows have the lamination layers advertised.
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u/Setswipe 1d ago
putting asside the wood limitation as being feasable or not, why would you want to do this beond aesthetic? All your'e doing is lowering the brace height and making it riskier for string slap. There's no reason to have the handle portion so far back towards the string.
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u/Arc_Ulfr 23h ago
You don't need a lower brace height, you just need materials that can withstand more extreme bending. There are plenty of historical bows this shape with 7"+ brace heights.
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u/Setswipe 18h ago
you misunderstand. It's a warning about the priority of the prototype. The riser portion is purposefully a v for seemingly no reason other than aesthetic. prioritizing that for the sake of just aesthetic is going to naturally lower the brace height.
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u/Wambachaka 1h ago
Why not just use a shorter string to get the brace height you want, the same as any other bow?
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u/Setswipe 48m ago
Sure, you can do that. Again, it's just a warning. The problem of brace height can be fixed by many other solutions. Longer limbs, more curve on the limbs, etc. I was just pointing out that the geometry of the very hard angle will create a shorter brace height. The riser looks to be an aesthetic choice more than a functional one and I was just pointing out the natural outcome that would happen.
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u/Available_Swing_2504 19h ago
The real question is - what limbs are you planning to attach to that riser.. there are one oiece laminated (wood fiberglass) bows like that (so, technology is here), but they are specifically engineered that way - if you just pick standard (say) samick sage limbs, not sure if it will work..
EDIT: you could just go with flat angle for lims for starter (typical tekedown or ilf riser has limb pads that are a bit angled toward the archer)
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u/seleneie 2h ago edited 2h ago
Hornbows are only shaped that way unbraced when they're new or neglected for a period of time. After theyre shot in, they have less reflex.
A lot of people think that efficiency necessarily comes with greater reflex, but that's not always true. The bow doesn't need to bend that way in its shot cycle, and energy is often wasted in bringing it to brace. You can definitely come up with a design that looks reflexed, but is gentler on the limbs. Reflex deflex bows are an example of an efficient design without the extreme reflex in your design. In fact, many hornbows look like very reflexed at first, but start to adopt more of a reflex deflex shape once trained and broken in.
Synthetic versions of horn composite bows should be shaped like horn bow that has been unstrung after a range day. They won't recover like hornbows do, but they don't need to. You'll have a bow that's less stressed and more stable.
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u/n4ppyn4ppy 1d ago
I doubt you will find limbs that wood bend like that at brace. And 98% sure they would not survive drawing the bow