5 curve design considerations

[Kidder]

I’ve really fallen in love with the look of a 5 curve bow. I own a mild 5 curve built for me by someone else and it’s a great shooter. I’d like to eventually build one but I’ve been able to find very little information on design considerations. For example what are the benefits/detriments of the design? From some of the bows I’ve seen online it appears they can be made shorter than many other designs - am I correct? At what point are the curves best added? What are the other considerations and nuances of this design? Thanks for entertaining my curiosity!

[bradsmith2010]

   I have made some gull wing shaped bows, but that usually just happened when I put reflex in the handle,,
so I am not an expert of the 5 curve, but if I was gonna try to make one,, i would put set back in the handle,, and slightly flip the tips,,  I think the bows profile would settle in on its own,, I may have over simplified as stated I have not made a 5 curve,,
    the best way to learn about a bow is to make them,, make your first one, and then modifiy it to your needs,
as far as length, you will be able to tell by the amount of set it is taking on how long you can make the bows,, and that will depend on the draw length,, just like any other bow,,
    if I wanted a 25 inche draw, just to be conservative I would make the bow like 55 and see how it did, trying the next one shorter if all seemed well,, hope that helps get you started and sure others with more experience will chime in,, if you try to make the bow to heavy in draw, it gonna pull the set back out of the handle unless you sinew back,,

[lonbow]

The 5 curve design is also one of my favourites I´ve built a couple laburnum 5 curve bows during the last year and they are very fast and promising for future experiments. The bows I´ve built are bethween 63 and 66.5" long at my draw length of 27". This being said I wouldn´t go much shorter then 63" (27" draw) because it might stack then. A RD bow can be made shorter than that in my opinion, because it has a better string angle.

But when not too short, a 5 curve bow has a good energy storage, especially when the outer limbs with slight recurves don´t bend too much. I think that this design has some advantages, especially if a wood with a high pressure resistance is used. The bend of a 5 curve bow tends to be more concentrated on the mid limb area and the fades are stiffer then usual because of the geometry of that design (so don´t make the mid limb area too narrow in proportion to the fades). The laburnum bows I´ve built tend to have low handshock. The reason might be that the bending areas are quite short. Furthermore, the moving limb mass is relatively low.

When using woods with a lot of tensile strength and pressure resistance like laburnum, the bow can be made quite narrow, which makes the limbs lighter. The setback handle reduces the bows tendency to twist in comparison to other reflexed designs. That´s the reason why laburnum 5 curve bows can be made comparatively narrow without any problem. I haven´t made 5 curve bows out of whitewoods like ash and elm yet. But I think they should have wider limbs that are almost parallel at the inner 3rd or of the limb.

lonbow

[RyanY]

My understanding of the short 5 curve bows is that they were sinewed which makes sense. Reflex right at the handle means the limbs will have to bend to a tighter radius than without reflex or with even reflex. Sinew would take advantage of that. That is generally not a good thing for an all wood bow considering the tighter bend radius would require thinner limbs which are harder to tiller and need to be wider for the same draw weight. The short recurves will help with energy storage/preventing stacking since the reflex at the handle will also increase string angle through out the draw. If the bow is simply reflexed at the handle and recurved without having the deflexed limbs then it would have the same advantages as other reflexed bows of more energy storage. Deflexing the limbs or letting them take set to get the 5 curve shape would eliminate that advantage since tip movement would be the same. The draw backs are many considering the issues above as well as the increased amount of work involved in making this style of bow. The advantage is that it looks cool as heck.    That's my perspective at least. I'm sure I'm missing a few things. I can't imagine a 5 curve bow out performing a simple bendy handle bow with even reflex through out its length.

[bradsmith2010]

i guess it would depend on how much reflex each bow was holding,,im temted to make one to see how it shoots through chrono,,sinew backed

[Kidder]

Guys - this is exactly the sort of input I was hoping for - thanks everyone! I had sort of thought they could be made shorter from viewing some of Simsons bows on his website - he’s got a couple that are stiff handle and 57-58 inches and he’s getting a full 28 inch draw...but then again he’s no mere mortal bowyer, so there’s that. It does make sense that a r/d would allow a longer draw. The one I have is wider and has longer, stiffer fades than I would have expected but, that seems on par with what was mentioned above. Here’s a pic of it in case anyone cares (NOT made by me).
Untitled by B Kidd, on Flickr

[bradsmith2010]

I was looking in Jim Hamms book, some looked about 50 inches,,

[Kidder]

I was looking in Jim Hamms book, some looked about 50 inches,,

I don’t have that book yet in my collection - are those stuff handled bows or bendy?

[bradsmith2010]

looks bendy, I post some pic tomorrow

[simk]

   I have made some gull wing shaped bows, but that usually just happened when I put reflex in the handle,,
so I am not an expert of the 5 curve, but if I was gonna try to make one,, i would put set back in the handle,, and slightly flip the tips,,  I think the bows profile would settle in on its own

I think you made yours just like many of the historical examples were made. We have some 5-curve medieaval hunting selfbows in Europe from laburnum. I assume they were made just from reflexed piece wood with flipped tips. The beautiful deflex curve then just occurred as set in the main bending zone  who knows...

I think its the same with the crim tatarian hornbows, although I'm not an expert there...

Cheers

[lonbow]

   I have made some gull wing shaped bows, but that usually just happened when I put reflex in the handle,,
so I am not an expert of the 5 curve, but if I was gonna try to make one,, i would put set back in the handle,, and slightly flip the tips,,  I think the bows profile would settle in on its own

I think you made yours just like many of the historical examples were made. We have some 5-curve medieaval hunting selfbows in Europe from laburnum. I assume they were made just from reflexed piece wood with flipped tips. The beautiful deflex curve then just occurred as set in the main bending zone  who knows...

I think its the same with the crim tatarian hornbows, although I'm not an expert there...

Cheers

That´s exactely the design I´m experimenting with! These bows were made in Lausanne until around 1850 by a bowyer with the surname "Bourgogne". Some of these bows have taken set, but some have an intentional deflex near the handle. This design amazes me because of its beauty and efficiency!

Nice bow Kidder!