static tips and levers

[bushboy]

The recurves need not be heavy just locked in with a heavy heat treating.also the 1 to 8 ratio plays a huge roll,i think people just tend to over compensate and make overly bulky recurves.

[PatM]

What do you mean by heavier or stiffer?

thicker or wider than an otherwise comparable length and draw weight bows, with out the hooks.

If there are advantages to static recurves that increase performance, then there should be extra wood required to store the extra energy. Of course, extra performance can also come from stressing a bow harder or is that what is really happening when special claims are made for bows with static recurves?

Realistically  the bow is not going to be thicker. Wider is generally recommended but I would definitely say that a static stresses the wood to a more optimal degree. Plus a static  effectively shortens a bow without cutting it shorter. Shorter limbs move faster.

[Stick Bender]

Some times I study theory tell Im blue in the face & think I understand whats going on but I never learn as much as I do building the bow that I'm studying about , this bow was the fastest bow I ever personaly built 65 ntn 8 1/2 in. strait levers  but there nether wide or thick I think widest thickness at the lever fade is around 5/8 & I tappered to the tips both in thickness & width  got the levers as light in mass as possible with out bending I agree that they dont need to be really thick or really wide , Im working on another one right now that Im going to try narrower levers but slightly thicker , I think to get performance out of these type bows is lightening mass as much as possible in the levers I dont totally understand why it works totally , but it does recurve or strait limb but light mass is key in my mind I could not of fliped the tips on this paticular bow with out taking set as light of mass as it was in the working limbs as the limbs where just starting to take set & lose reflex but Im not convinced  that a recurve vs a strait limbed bow of equail reflex is faster , but I will just have to build another bow and find out , this bow eventually broke about 8 in. Out of the handle fades !

[Stick Bender]

Thickness

[bradsmith2010]

shooting said desings through a chrono,, or for distance takes some of the guess work out,,
some of Marcs bows, certainly show great cast with the recurves,,
and I am sure there are others that have test results,,
straight tip bows are underated I think, and can shoot quite well when designed properly,,
when the whole bow is refelxed and the tips are in front of the handle ,, equal to a recurve the results can be surprizing,,

[Selfbowman]

I don't know about all the math but if the static does not work the extra mass does not have that much effect in performance. The mass is just along for the ride. That's why I have not built them anymore. Arvin

I beg to differ.  A well built static will outperform a straight limb bow by a wide margin

Marc I have been wrong before . I did not see it working for me. It was a good shooter but not that much different . I do know that getting the mass in the right place makes a Hugh difference. Maybe I had the mass in the wrong place. . Arvin

[bradsmith2010]

how much is a wide margin,, could you share some stats, ,thanks b

[gfugal]

Im not convinced that a recurve vs a straight-limbed bow of equal reflex is faster, but I will just have to build another bow and find out

I think it depends on a lot on the length and bow design/material. That's what makes these comparisons so hard because there3 are so many variables. Like I was saying in the other post, longer limbed bows don't benefit so much from reflex because the reflex helps by improving string angle (and maybe some other factor that has no good explanation yet). Longbows already have good string angle so it might be more beneficial to reflex like you said instead of recurving. However, I believe shorter bows closer to 50", rather than the usual mid 60" bows, will have much better advantages from a recurve. Regardless of length though I would say it's probably safe to say that either reflex or recurve would be better than a simple straight-limbed bow, as long as the are comparable in material and designed/tillered correctly.

[DC]

Why is a low string angle a good thing?

[gfugal]

Why is a low string angle a good thing?

I wasn't saying shorter bows are better or not, I was just saying a recurve on a longer bow is going to improve the string angle less than a recurve on a shorter bow. (Let's say for example's sake a recurve improves by 5% on a 68" bow, but 12% on a 55" bow. pulled numbers out of my butt, so don't hold to those values as anything real.). Sting angle is important because it affects the force-draw curve. Bad string angle leads to stacking and you have less stored energy. Good string angle leads to "smooth draw" with no spike in weight gains. This ensures a fatter force curve and thus more stored energy. The speed of a bow can be simply boiled down to its stored energy and how efficient it is at converting that energy to arrow speed. 

[DC]

My question wasn't really about recurves and such. It was just a question in general. You came close to an answer but I'm greedy. You said it causes stack or sweet draw. Kind of meaningless. If I assume that stack means hard and sweet means easy(I've gotten that impression) does that mean there is a greater mechanical advantage with a low string angle? I'm not trying to be a jerk, I've been after this for a while. If there is a greater MA at low angles,and I think there is, how do you figure it.

Lots of big smiles to show I'm not a jerk. If it's a big complicated math formula just tell me that.

[gfugal]

My question wasn't really about recurves and such. It was just a question in general. You came close to an answer but I'm greedy. You said it causes stack or sweet draw. Kind of meaningless. If I assume that stack means hard and sweet means easy(I've gotten that impression) does that mean there is a greater mechanical advantage with a low string angle? I'm not trying to be a jerk, I've been after this for a while. If there is a greater MA at low angles,and I think there is, how do you figure it.

Lots of big smiles to show I'm not a jerk. If it's a big complicated math formula just tell me that.

It comes down to how the angles change and torque. a bow would act like a simple spring if the force was applied at the same angle all the time throughout the bend but it doesn't, therefore, the torque on the limbs is changing and likewise, its restoration force depends on it. I haven't seen anyone calculate it, it's probably pretty complicated especially when you add stuff like recurves. I don't understand it fully either. If someone can offer a better explanation that would be amazing. I just know a lower angle causes the poundage to increase more gradual, and a greater angle causes the poundage to increase rapidly (hence the stacking).

[DC]

Thanks. Can you explain torque in this application. I understand torque as in wrenches and drag racing. Where is the twisting taking place?

[Selfbowman]

I prefer longer bows. I feel they are smoother have no stack and less finger pinch. Thus a smoother release. As far as levers . They go with shorter bows I would think. Wide limbs to mid llimb. Just not my deal. Arvin

[Pat B]

Once the string angle hits 90 deg the bow begins to stack, like hitting a wall. It won't pull much farther and the draw weight increases rapidly then you hit a stop. By bending the tips into reflex a longer draw is possible because it can be drawn farther before the string angle hits 90 deg.
 This also adds more stress to the bow so the tiller has to be spot on.
Once the string hits 90 deg the force stops bending the limbs and the force is pulling along the limb. I hope this makes sense. I know what I'm trying to say it's just hard to explain.