Disadvantages of parallel limb technology?
 

Are there any disadvantages to parrallel limb designs where the limbs are at 40+ degree angles to the riser? I have heard that this puts a lot of stress on the limbs at the limb pocket area which might lead to limb failures after an extended period of time.

RE: Disadvantages of parallel limb technology?
 

I would imagine the limbs are built to handle the stress loads, but other than that possibility, I can' t think of any disadvantages...

RE: Disadvantages of parallel limb technology?
 

The biggest disadvantage I can think of is parallel limb bows are butt-ugly.[X(][&:]:D

A short limb is definitely more highly stressed than a longer limb of the same strength, and it will fail sooner. But probably not one guy in ten thousand keeps a bow long enough or shoots enough to work those limbs to failure.

RE: Disadvantages of parallel limb technology?
 

Man your crazy:D

parallel limb bows look the best to me - they are beautiful:D:D

RE: Disadvantages of parallel limb technology?
 

I too think parallel limbs are sweet looking. [8D]

RE: Disadvantages of parallel limb technology?
 

You just now figgerin' that out, Rack? LOL:D:D

RE: Disadvantages of parallel limb technology?
 

There was once a time when I agreed with your statement Arthur but now.....:)

I think they are an acquired taste...sort of like an ugly woman.....:D

RE: Disadvantages of parallel limb technology?
 

Beauty is certainly in the eye of the beholder, isn' t it?;)

Logically, it would seem that the VFT/parallel limb bows would be much more difficult to shoot well for a couple of reasons. First, all of the risers of such bows are highly reflexed, and should be less stable, and more prone to torque. I know that this has been discussed quite a bit over the years, reflexed v. deflexed risers, etc.;)

The second reason that would seem to be a possible accuracy problem is that the limbs do not really move forward much at all, compared to a more " normal" bow.
When a shorter riser/ more vertical limb bow comes from full draw to brace, the limbs move forward more, and the arrow is propelled forward (relatively) more by limb movement than by string movement. The VFT bows' limbs do not move forward much, so the arrow is propelled more by string movement than by limb movement. It would seem logical that a limb would be able to move forward with more straight-line consistency than a string, which would seem to be prone to all kinds of torque and oscillation. Again, this is just what appears to be logical.;)

BUT, there seem to be quite a few guys on several forums posting that bows like the Bowtech Extreme VFT and the Mathews LX, both of which have highly reflexed risers, parallel limbs (VFT) and relatively low brace heights, are shooting very well, as well as any bow that they have shot before. Maybe logic doesn' t work in this case.[:o]

I' m not really sure why, maybe someone can explain it better. I do know that a few years ago, I built two experimental bows that were somewhat like the Martin Kam-Act, except that they had only one limb and one cam + an idler wheel. The one I made for my kids worked OK, if it was shot with a release aid. When they (or I) tried to shoot with fingers, the string oscillation was so inconsistent that groups were terrible, even though it shot pretty well with a release. The bigger bow that I made for myself had more problems, especially with material strength, etc. I could only get about 45# out of the materials that I had at the time, and the draw length came out too long, but it was nearly impossible to get decent or consistent arrow flight with that bow that propelled the arrow totally by the string movement. It was the only bow that I have ever shot that had absolutely NO recoil, however. I really thought that the VFT type bows would be running into similar problems, counting so much on the string movement for arrow propulsion, but apparently, it is not really a problem for the engineers who know what they are doing!
[:o]

I don' t think there is much question that a shorter limb would be under more strain than a longer one. If you add a lot of prestress to that short limb, as Bowtech does, it would again seem logical that this would be a problem area. Since very few failures of Bowtech limbs are reported, it would seem that Kevin has engineered the bows so that what would seem to be a problem area in fact is not much of a problem at all.

I personally do not have a VFT bow, although I do have a Pro 38 Dual Cam, which borders on being able to be called VFT, since it has a long, straight riser, and limb angle that is much greater than anything else I have owned. If logic would apply, it would be much more difficult for me to shoot this bow accurately than say, the Continental Denali that I had with a deflexed riser and 9+ inch brace height. Experience has proven otherwise, at least for me. I have no explanation for this, however.:(

One real drawback the the VFT design is found when you but them in a bow press, at least a conventional bow press. It is much more difficult to compress the limbs on a VFT bow than a more conventional bow. It is highly recommended that you back off on the limb bolts before pressing a bow with VFT.

I guess the real advantage to them is the lack of recoil. I personally have not seen a strong connection between lack of recoil and consistent accuracy, though. I really think I can shoot my early " 90' s Darton Viper as well as any bow I have tried. Just my thoughts. Probably not worth too much, but I am bored at the moment.[&:]

RE: Disadvantages of parallel limb technology?
 

Especially when they are in the photo of a 150 class 8pter...eh...Rack[:-]

RE: Disadvantages of parallel limb technology?
 

Surprisingly, I have had the opposite experience. Generally speaking, when a bow exhibits less recoil I find that I am less worried about the recoil of the bow thus allowing me to maintain better shooting form. It is entirely mental in my case though I can see where this might not be an issue with others.

RE: Disadvantages of parallel limb technology?
 

It is with me... I' m exactly like you in that regard... The less recoil, the better. It' s not that recoil scares me, it just makes it extra hard to relax and trust the bow isn' t going to fly out of my hand, even with a sling. It' s mental, but it is what it is...

RE: Disadvantages of parallel limb technology?
 

I have the same experiences aas Frank. The less recoil, the better I shoot.

Aesthetically, I' ve come to like them (VFT style bows), but really I don' t think I' ve seen many really nice looking compounds (other than the paint/anodizing). For looks, I think a long slightly reflexed riser, with a set of Recurve limbs, and a pair of dual hatchet cams is about as nice looking as it gets in a compound. Unfortunately, I just can' t stand to shoot such equipment anymore :D.Those style designs are super accurate for sure, but unpleasant (for me) to shoot. I shoot higher poundages and I want smooth; as little jump/recoil as possible while giving me the performance I desire. A bow with traditional limb angles and alot of string and cable length are just too thumpy/shocky for me..unless I get a 50 pounder for targets. I' ve gotten so used to VFT type angles that even my 2003 Hoyts were really starting to get on my nerves, LOL:D Guess I' ve been spoiled by Patriots, VFTs, Legacy' s and LX' s.

Now..if ya wanna talk pretty..nothing beats a custom longbow or recurve...Cocobolo riser...bocote limbs...some osage accent stripes in the riser..whooooweeeee :D

RE: Disadvantages of parallel limb technology?
 

The only real disadvantage I can find, is that the same axel to axel length bow, with parallel limbs, will generally be heavier. Machined aluminum risers are relatively heavy, at least when compared to limb weight. If weight is important (and it is to many), then the less riser material, the better.

RE: Disadvantages of parallel limb technology?
 

OK, I can see your point if you are talking about a significant amount of recoil. I remember putting 3 shots inside an inch group at 30 yards with my old Jennings Carbon Extreme several times, but if I shot very many groups, things would fall apart. That baby would put a hurtin' on your bow shoulder!

Maybe my nerves/brain are too burnt out to notice the difference. I just don' t notice much difference in recoil between the bows I have owned, and the lowest recoil ones weren' t the most accurate (for me). The lowest recoil bows I have owned would probably be 1. Mathews Q2 XL, 2. Mathews MQ1, 3. (real close) McPherson 38 Special, 4. Firebrand Discovery, 5. Bowtech Pro 38 DC. At least for me, the Bowtech can shoot rings around the other 4, especially if you are talking about worst shots in a group.

RE: Disadvantages of parallel limb technology?
 

BowTech dosen' t recomend backing the limbs off, Mathews does. There is less stress on a parallel limb designed bow' s limbs than on a more verticle limb bow. Look at a diving board, the stress is spread over a longer working area. the more verticle the limbs are on a bow, the more the limb tip is being " pushed" directly toward the limb pocket. There is probably a math ratio that can be worked up that shows the ratio of the riser' s reflex compaired to the limb angle. Say a bow with 7.5 inches of brace with a 44 degree limb angle, 2.5 inches of reflex and 11 inches between the limb pocket and string would be just as forgiving as another bow with a 6.5 inch brace, 28 degree limb angle, 1.5 inches of reflex and 8.5 inches between the limb pocket and string. :D

RE: Disadvantages of parallel limb technology?
 

I agree, the parallel limb bows are ugly!
Besides, who wants an ugly woman!!!??

Clint

RE: Disadvantages of parallel limb technology?
 

It seems like the parallel limb design mimics a chalk line, where the line marks a straight path between two anchors until it is stopped.

I' m so green at this bow thing but, I' ll throw this out anyway...


These Oneida folks look like they' ve been on the parallel limb/chalkline train quite a while. Again, to this tenderfoot, it looks as if you put straight limbs and " normal" cables and cam(s) etc. on an Oneida riser, it would look much like today latest and greatest.

I hope this isn' t a thread killer ;):):D

RE: Disadvantages of parallel limb technology?
 

The double recurve carbon limbs on my Accu-Riser II and Super Nova look far better than any parallel limb bow imo.
You guys who think parallel limb bows look better must be the same guys who think the girls look better at closing time when you' re drunk. LOL
Of course, Jeff knows best.
No bow is as pretty as a fancy recurve.
Especially, my Trails End Recurve. ;)


Sag.

RE: Disadvantages of parallel limb technology?
 

Ugly women need loving too:eek:

RE: Disadvantages of parallel limb technology?
 

I know this wasn' t the original question but everyone seemed to answer on the asthetics of the design. I think that parallel limb bows like the Bowtechs and Mathews are very sweet looking bows and I may be adding one of them to my collection soon.[:-] I have friends in both camps and they shoot them like they are going out of style with no signs of weakening at any points. Low recoil, speed and accuracy. What more can you ask for?

RE: Disadvantages of parallel limb technology?
 

[quote]The VFT bows' limbs do not move forward much, so the arrow is propelled more by string movement than by limb movement. It would seem logical that a limb would be able to move forward with more straight-line consistency than a string, which would seem to be prone to all kinds of torque and oscillation. Again, this is just what appears to be logical.[quote]

Your being illogical :) Since VFT limbs move upwards and a shorter distance than normal limbs they can be more accurate, more straight-line consistent.

The string is what propels the arrow, not the limbs nor the direction the limbs travel. The string travel and speed is what causes arrow acceleration, so if the string travels forward, which it must do, and the parallel limbs travel a shorter distance to achieve the same string travel of normal limbs, then accuracy should increase?

RE: Disadvantages of parallel limb technology?
 

I have to agree with this. Long risers with short parallel limbs are really damn ugly. I like my Extreme VFT but I don' t think it is pretty. I like it for its' performance. Did I say this bow is ulgy?

Now the Merlins with the reflex limbs, wow, they look nice. Recurve with cams :)

RE: Disadvantages of parallel limb technology?
 

All design is compromise, but we live in an age where there are rapid advances in material design and manufacturing, so that designs which wouldn' t work so well years ago are fine now.

With VFT the limbs move very little compared to other designs. If you think about it they have to have limited movement. That means that the cams have to rotate more or be larger, which might introduce problems that have to be solved with respect to noise and smoothness of draw. I suspect that stress on the string is greater, as well as on the axles and bearings. This means that more care has to be taken with materials and manufacturing tolerances to get a bow that performs as desired.

RE: Disadvantages of parallel limb technology?
 

The days of beautiful compound bows are gone. These short limbed, long risered bows of today are being built for speed........thats all. Pretty? Nahhhhhhhhhhh!

RE: Disadvantages of parallel limb technology?
 

I love the parallel limb design I think they look great.

nubo