14 mm small ID bands - brands similar to primeline

[Sorcerer]

You missed the point entirely. Please read the post again. The only reason I mentioned the Abellan was that testing it was the reason I was at the pool in the first place. I wanted to see how it performed with the bands that came with it. The Abellan came with 14.5 mm small ID and that is all I've ever used on it. They work great and I've had no reason to try any other bands for comparison. But I had been using 16 mm large ID bands on the Wong, so I wanted to see how it performed with 14.5 mm small ID. The difference was dramatic. Besides the great increase n recoil, maybe I should explain muzzle flip/muzzle rise. People who use rear handled guns may not be familiar with the problem. Mid handled guns are very popular in Southern California because we often hunt in poor visibility and thick kelp. We shoot big fish so we need power for penetration, but we also need to be able to swing the gun easily. A rear handled gun that is long enough to have the power will be hard to swing in those conditions.

Well designed rear handled guns place your hand very close to the recoil force from the bands. But with a midhandled gun, the handle is well below the force from the bands, so the gun tries to rotate around the handle. The muzzle rises as the shaft leaves the gun and the rear of the shaft is pushed upward, causing the shaft to shoot low. To minimize this effect, we can increase the mass of the gun and/or try to back up the butt so the gun can't rotate around the handle snd cause the muzzle to rise. I had been using the Wong with three 16mm large ID bands for a couple of years and the recoil was controllable with little muzzle flip. I showed the fish photo simply to show that with the first shot of the gun, it was accurate enough to hit that fish.

Now back to the pool. The 14.5 m small ID were so much more powerful that I bruised my chin and muzzle lift was so severe that the shaft passed under the entire target. Removing one band helped, but the shaft still barely hit the bottom of the target. If I had been shooting at a fish, I would had missed completely and probably not realized why.

To summarize- with the same gun and shaft, the 14.5 mm small ID bands seemed to provide a lot more force that the 16 mm large ID bands, even though the cross sectional area of the 14.5 mm is a lot less and wishbones were exactly the same in both bands. I don't know why- I'm just telling what I experienced.

Bro you are still comparing apples to oranges.

A 16mm band at 280-300% has less power than a 14mm band at 350-380%.
The power increase is not linear with stretch ratio but exponential.
The band diameter has VERY little to do with recoil, muzzle lift but rather the power stored in rubber based on its stretch ratio.
You cant just go out and say oww fuck the 14.5mm had so much more recoil or power than 16mm. Its not about band diam as you try to portrait it.
I can understand your experience but it has no real value.

A comparisons like yours is why there is so much bad information and advises based on human perception in first place instead things that we can measure.
A human perception is very dangerous thing...

 

[Bill McIntyre]

"A 16mm band at 280-300% has less power than a 14mm band at 350-380%."

For someone so interested in precision, I can't understand why would you make a statement so broad as to be meaningless. In my case I said that I used a 350% stretch ratio on the 16mm large ID and a 360% stretch ratio on the 14.5 mm small ID. You could have commented on that specifically, but maybe you didn't bother to read it? Would that difference in stretch ratio account for the big difference in power? I don't know. What do you think?

"A comparisons like yours is why there is so much bad information and advises based on human perception in first place instead things that we can measure.
A human perception is very dangerous thing..."

When a gun punches me in the chin and has so much muzzle flip that the shaft goes under the entire target I think my perception is pretty accurate. I've been spearfishing for over 70 years and have used a lot of different spearguns. Would you like me to have a scale in the pool to measure pounds of recoil? I haven't heard of that being done but I'd be delighted to learn more if someone is doing it. Of course my perceptions are based on the gun being hand held. I suppose we could put a bench vise in the pool to hold the gun steady. Then the gun couldn't recoil and the muzzle couldn't rise but that isn't the way we spear fish. We have to control the gun with our hands and arms, so we have to rely on our PERCEPTIONS when we decide whether a gun shoots well. Just last week a friend lost his three front teeth when he didn't get a chance to lock his elbow shooting at a bluefin tuna. He said it hurt. Good luck trying to tell him his perceptions don't matter.

In my pool session the only difference was 10% of stretch ratio. I really wish I could go back and try both sets of bands with the same stretch ratio but I can't. But at least I offered some facts. All I've heard from you is a bunch of grumbling that no one knows what he is talking about when it comes to comparison of band IDs. If you can jump in a pool and conduct a test like mine but with constant stretch ratios, I'd love to hear about it. Or if you can refer us to someone else that has done it, we'd be eternally grateful. But just saying that everyone is wrong without telling us who is right doesn't help much.

Until we get the facts, I'll just have to wonder why so many gun makers are offering 14 or 14.5 mm small ID bands now. Do they know something? My biggest gun now is 63" Ulusub midhandle and it came with three small ID bands. My "perception" is that I love the way its shoots. In the last few years we've had a run of bluefin tuna up to 300 pounds in Southern California and a lot of my friends are going for them. A very popular gun is an Ulusub that is 69.5" long and it comes with five 14.5 mm small ID bands. Why wouldn't Ulusuib use the thicker bands on a tuna gun if they worked better?

 

[musubi]

Can anyone tell me how these brands compare to the Primeline 14mm small ID:

- Pathos TNT 14 mm
- Salvimar S400 14 mm
- Rob Allen 14 mm
- Riffe Gorilla 14mm

I can only get these in my area but would like to have the same characteristics as primeline.

Have you tried Primeline bands before? If so, and if you still have some, try buying a foot or two from each of the brands you mentioned and feel it to compare. When you say progressive, what are you looking for in the rubber?

I personally believe you can make any brand of rubber work for you if you take the time to make adjustments along the way.

 

[Sorcerer]

I think you extrapolate and exaggerate so much with your perceptions but yes, there are some bands on the market that I would call extremly bland at high stretch ratios compared to good 14-16mm.
One good example I have still here:
Salvimar green 16mm (ones that are uniformly green) that were advertised to be good all the way to 400% (?!) at 16mm. Well I can say they definetly can get close to 390-400% and not break next day but id say they are the weakest bands Ive ever used.
Was obvious when I can almost single handily load a 16mm 380% band compared to primeline 14mm 350% on a 110cm gun.

Its less of a case in that particular manner about diameter, small or big bore but rather so different rubber type/compound than typical primeline rubbers available from most resellers as cressi/epsealon and similar.
Majdq8 has a great example on his salvimar hero video, how bullshit manufucters are when same gun is being sold with rubbers that are not even close to same spec.
We say - when you dont know why its becouse of money.

From my perspective most manufactures will do something not becouse its better overall but becouse of the client beliefs that its better or its cheaper/easier available. Everyone jumps on the bandwagon (lol) but have we seen yet a clear cut why apples are better than oranges? If everyone is so sure why they dont show it to the world?
Im way to resistant to marketing bullshit these days and placebo type shit.

"A lie told 1000 timea becomes the truth."

All those manufuctures have much better means and resources to prove that they are right, yet nobody does it. INTERESTING.

I dont really wanna go down more this road.

 

[popgun pete]

The cross-section of the rubber is what counts , the area in other words, the rubber does not care what shape it is, unless it is very thin, which does not apply here.

 

[Black_Reef_Co]

My only counter argument from an engineers perception is the equation F=mass x area. Increasing rubber diameter is exponential in regards to mass, and also significantly affects retraction rate [i.e. acceleration] no? Contact/drag with water will also increase significantly with larger rubber diameters but I could be splitting hairs.

 

[Bill McIntyre]

My only counter argument from an engineers perception is the equation F=mass x area. Increasing rubber diameter is exponential in regards to mass, and also significantly affects retraction rate [i.e. acceleration] no? Contact/drag with water will also increase significantly with larger rubber diameters but I could be splitting hairs.

Yep, there are those unknowns. As you have read in previous posts, I was claiming that 14.5 mm small ID rubber was more powerful than 16mm large ID, although I muddied the waters buy stretching the small ID a bit more. But anyway, I just tried to compare cross sectional areas of those bands. It gets tricky since some sources express the ID in mm and others in inches, and There can be differences in OD from one end of a back to the other. But if I got it right, the 16mm large ID has 1.18 times the area of the 14.5 mm small ID, or put the other way the 14.5 small ID has 0.85 the area of the 16 mm large ID. If in fact the small ID bands produce more power, maybe it because of reduced friction.

 

[popgun pete]

My only counter argument from an engineers perception is the equation F=mass x area. Increasing rubber diameter is exponential in regards to mass, and also significantly affects retraction rate [i.e. acceleration] no? Contact/drag with water will also increase significantly with larger rubber diameters but I could be splitting hairs.

The mass of the bands is trivial compared to what the bands are pulling.

 

[Black_Reef_Co]

Yep, there are those unknowns. As you have read in previous posts, I was claiming that 14.5 mm small ID rubber was more powerful than 16mm large ID, although I muddied the waters buy stretching the small ID a bit more. But anyway, I just tried to compare cross sectional areas of those bands. It gets tricky since some sources express the ID in mm and others in inches, and There can be differences in OD from one end of a back to the other. But if I got it right, the 16mm large ID has 1.18 times the area of the 14.5 mm small ID, or put the other way the 14.5 small ID has 0.85 the area of the 16 mm large ID. If in fact the small ID bands produce more power, maybe it because of reduced friction.

I believe that is due to retraction rate being higher in small-ID 14.5mm vs 16mm, because it is thinner at the same force of stretch , and the relationship between stretch % and force in the rubbers is exponential, then linear at 300% to 400%. I think friction/drag in the water is more important than the weight when it comes to bands. So I see Pete's rationale.

the equation that summarizes this is the relationship between kinetic and potential energy. Pot. energy = 1/2 mass x velocity. Let's use Pete's idea of disregarding mass, then velocity must be looked into. Why would the small ID have more velocity ? Id argue 50% because it makes more power on average across the powerband from mech to muzzle and 50% due to a thinner diameter, even if the peak power of the 16mm a few more pounds of force.

Id love to find a way to make an equation for this, factoring in rubber sidewall specs, mass, and drag coefficients.

 

[Sorcerer]

Has anyone ever seen or found a paper mention on the band contraction Vmax both in air and water?

The only paper mention I found was around 31-33m/s and without clear indication in what medium so I guess it was air.

Jesse Spillers paper has no mention of that at all unless it was simply dirived somewhere from V= s/t or V=a*t

 

[Bill McIntyre]

In the absence of formulas, an old fashioned way to compare would be a pool test like those that spearq8 does. Shoot the same gun using the same shaft at the same distance with both sets of bands and compare penetrations.

I've always wondered about those penetration tests. Does the shaft happen to hit a hole from a previous shot? But I guess if you did several shots you could account for that possibility.

 

[popgun pete]

Band retraction speed is a measurement, not a property, unlike density which is a property of a material. Bands will have a free retraction speed, but once it has to move something other than itself that speed will slow down. For example a band retracting would have no trouble pulling a sewing needle, but attach it to a weightlifting bar and it will be stopped in its tracks.

 

[Bill McIntyre]

Band retraction speed is a measurement, not a property, unlike density which is a property of a material. Bands will have a free retraction speed, but once it has to move something other than itself that speed will slow down. For example a band retracting would have no trouble pulling a sewing needle, but attach it to a weightlifting bar and it will be stopped in its tracks.

And that’s why we need a real world test. How fast does it actually push a shaft. And since speed would be very hard to measure, a penetration test.