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09-12-2019, 02:30 AM | #1 |
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14 or 14,5mm bands for 100-105 cm spears?
Hello everyone.
The small ID band "revolution" have not yet reached Denmark, so it was quite the shock to see the amount of power that can now be squeezed out of the traditional 2 sling setup (spearq8 videos). The only "problem" is that I cant find much info on how to setup guns under the 82-90 cm mark. The average effective visibility here is usually 3-5m, and most fish do not pass the 4kg mark. So there is no real need for big cannons. Most spearoes here use 75's with 2 x 16mm (or 1 x 18mm) rubbers + a 115 cm, 6,5mm spear. I feel that this setup could be boosted quite a bit with the new generations of small ID rubbers, but I am unsure where to begin. It would also be very interesting to see if it would be possible to make a short 65-70 "cannon" with a 100-105 cm, 7mm spear. A 100 cm 7mm spear has the same mass as the standard 115 cm 6,5mm, so I feel that a 100-105 spear would be a good place to start. I just wonder what thickness of rubbers to use. Short spears should be more resistent to whipping(?), so mabye 2 x 14,5mm @ 380% would not be a problem? I also wonder if a shorter spear will affect accuracy? What do the experts say? My spear/rubber ratios are based on this video by spearq8: https://www.youtube.com/watch?v=FSK4HkkimXk&t=12s Last edited by Andersp90; 09-12-2019 at 06:02 AM. |
09-12-2019, 06:53 AM | #2 | |
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Re: 14 or 14,5mm bands for 100-105 cm spears?
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09-12-2019, 07:39 AM | #3 |
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Re: 14 or 14,5mm bands for 100-105 cm spears?
Hej Anders - velkommen.
Remember, you don't need huge stopping power for DK hunting. I'd say just get some 14mm, cut them at around 360-380% and be done with it. But remember to modify the handle if you really want to get results like those in Majd's videos. Finally, this test is much more representative of the size of shaft and guns you are using (it's an 82cm gun): https://www.youtube.com/watch?v=UBNw4PLqPfI (disregard that it says "roller" - Majd changes the setup to double Small ID later in the video). Let's see if Small ID rubbers will finally make it big in DK - it's about time... |
09-12-2019, 11:22 AM | #4 |
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Re: 14 or 14,5mm bands for 100-105 cm spears?
Denmark, in my book, means extra cold water. Rubber bands loose their properties in the cold. The general opinion is that up there you are better off switching to pneumatic guns.
Do some research but Salvimar Predator (aluminium) or Dark Side (carbon fiber) along with Mares Cirano (several models) seem to be easily available models that work great. You can have a look at the prices in Scubastore for example. Mikel Mikel |
09-12-2019, 11:43 AM | #5 | |
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Re: 14 or 14,5mm bands for 100-105 cm spears?
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I think Anders is a rubber lover and not looking to be converted - I know he is a long time member of a Danish online forum where we often talk about airguns. As for the cold... While the water back home is cold'ish, it's not Russia, Norway or Finland cold. Most fish are gone when it gets really cold, so few Danish spearos hunt in the coldest months any way (except for a dogged few going out for a New Year's cod). The rubbers do loose some oomph but far from all of it. I think somebody back home tested it and is was perhaps 20% max in the cold months, but I can't recall in detail. Also, keep in mind, Danish hunting is not about monsters shot at long distances, it's more about hours of very silent surface stalking and having a no non-sense setup that swings nicely and balances perfectly for those long days in the water. The most common gun is probably a 75 band gun. With the original question in mind, I would even consider a 6.75mm shaft and double 13.5-14mm rubbers - sort of a faster shooting Med style setup, I guess. It doesn't matter if the shaft is a bit light and runs out of punch faster than a heavier shaft - the viz in Denmark is not conducive to long shots anyway. In regards to small ID rubbers on fairly short guns, I have a Pathos 100 with double 14mm small IDs on it. It has a lot of power and I still have to put some effort into loading it and hold the grip properly. On a recent trip, a friend of mine brought a 90cm Sigal gun that he rigged with double 13mm small ID from Sigal and a 7mm Salvi shaft. It was rigged for a female newbie spearo but all three of us absolutely loved shooting it. It was easy to load and just enjoyable to shoot - really just a point and shoot gun with great accuracy. I used to take it for an hour or so once a day in the shallows to grab us some nice dinner fish. My friend shot a 12kg GT on it and though it was close it was not suicidally so. He also used the gun in a pool session with a bunch of beginners (he runs a spearing club) and he said pretty everybody hit bulls eye with that gun. I don't think the gun is special. Rather, I think it is the combination of a really nice shaft on it and then the power which is not too much, but obviously still plenty. As for oleos: Shorter pneumatics tend to not balance that well, though of course, they can be modified to do so. Also, I can personally not speak in favor of the newest Mares Cyrano 1.3 (or whatever they call it). The metal trigger and line release is an abomination (I have used that handle in a recent build of mine). I don't often talk crap about products, but I lost two dogtooth tuna due to the line release putting too much friction on the trigger mech. They probably made it in stainless steel for the sake of bling and because they had some incidents of the previous plastic ones breaking (Yes, Marco - I know yours is fine;-)). As for the Predathor, I often recommend it is the best bang for the buck and will get you into vacuum muzzled guns very affordably. Not much not to like (except you may want a sturdier slider and don't run the gun at super high pressures as the shock absorber o-rings will start busting). But Predathors are supposedly a bit heavy in the shorter sizes. Maybe the 90 starts being neutral(?). Last edited by Diving Gecko; 09-12-2019 at 12:08 PM. |
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09-12-2019, 02:13 PM | #6 | ||||
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Re: 14 or 14,5mm bands for 100-105 cm spears?
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The temperature ranges from 6 to 20 degrees celsius during the season. There are people using pneumatics here, but they are a tiny minority (no disrespekt to gecko). I was one of them for a short while. (65 predathor and 90 cryano evo hf). But I never really got used it. Quote:
I have watched all his videos to death, including that one. My base for the "experiments" will be a bleutec simple carbon 75 open with a 105 cm, 7mm spear from hunt. It will be delivered with 2 x 14mm small ID bands from bleutec (primeline). Will do some testing in the pool to see what I can squeeze out of it. If its a sucess, I will try and see if they will build me a 70, with some custom changes, to maximize the available stretch. Quote:
Lamberto did a speed test on some different invert roller setups. https://youtu.be/NvChOVWqfL0?t=131 As can be seen in the video, the 7mm spear from the 75 and the 6,5mm from the 85, both reached their targets after 170ms. So they must be going at the same speed. And it gets REALLY interesting when you compare those speeds to a well setup doubble rubber gun: https://www.youtube.com/watch?v=SMhwmRtcdz4 If you lower the playspeed to 0.25, its easy to count the frames from the gun is fired, to the spear hits the target (about 56 frames). The video is shot at 240 fps. So the spear travels 1m in 46,6 sec. The spears in lambertos video need 56,6 sec to travel 1 meter. I know that the invert roller video "speed" i not precise, because its filmed at pretty low framerate. But I still think that it hints at: 1. Majd's theorized "speed barrier" might be real. 2. Invert rollers offer no speed advantage 3. Spear weight is the most important factor when looking for more range (because the speed is "hard capped"). Quote:
Last edited by Andersp90; 09-12-2019 at 05:03 PM. |
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09-12-2019, 03:29 PM | #7 |
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Re: 14 or 14,5mm bands for 100-105 cm spears?
Hej Anders,
You might be right about the speed difference not really being there once we can power up thicker shafts, too. But that said, I am not sure we can use Lamberto's video to make your point since it compares speeds between different sized guns and between different guns, no? I had a look at Majd's video and how do you get 56 frames? In the slow mo, in the last clip, I can only count 17-18 frames, maybe I am doing something wrong. But it's late and I can't figure out if uploading to Youtube drops frames and by so, by which ratio. As for the cave hunting, it's more like what the Americans would call hole hunting, I think;-). Just so you guys don't think Anders freedives into a cave looking for fish, though that would be rather cool;-). It's probably since the clay holes that cod can sometimes be found in resembles small caves and that's the word we use for them in Danish. Or maybe it's small rock caves - anyhow, the word 'cave' in Danish is often more akin to a smaller "den". OK, I got carried away. Def time to sleep now, haha. Last edited by Diving Gecko; 09-12-2019 at 03:52 PM. |
09-12-2019, 04:34 PM | #8 | |||||
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Re: 14 or 14,5mm bands for 100-105 cm spears?
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The predator was really nose heavy. Like the cayman 2000. And the spear was made of jelly. Dont know if they "fixed" that problem. Biggest problem though was aiming. When I thought I was aiming straight, I was actually aiming slightly down. We realised that in a pool session. Gave up on it after that. I tried my friends bleutec simple carbon 75 closed muzzle (im getting an open), and loved it instantly. On land it is really heavy, do to the body/tube being a solid carbon monoblock. But its light as a feather in the water + the weight really eats alot of the recoil, with the handle taking care of the rest. Its a brilliant gun imho, and the reverse tigger is REALLY reverse. It offers 1-2 cm extra stretch over my mares viper pro ds (also reverse trigger). Hopefully they will make me a 70, with a slightly thicker tube (to compensate for the loss of 5 cm tube), with the hole for the slings moved closer to muzzle for maximum stretch. That would be a little evil monster! Quote:
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https://www.youtube.com/watch?v=--G2HwUc3PE Last edited by Andersp90; 09-12-2019 at 05:07 PM. |
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09-13-2019, 06:11 AM | #9 |
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Re: 14 or 14,5mm bands for 100-105 cm spears?
The smallest gun I have thoroughly tested and worked on would be 82cm. It was pretty amazing how much power I was able to get out of that package while still keeping absolute accuracy. I actually use the 82cm guns now in hunting situations where I used to use a Riffe 120cm gun just a few years ago. I think for smaller guns like 70cm to 75cm ... I would try and get some small ID band material that is around 13.5 mm. From my experience I find that you need to get the smallest diameter band you can get away with for the shaft mass you are using. A 6.5mm @ 105cm shaft is a pretty light shaft, so most likely it can get to terminal velocity with even 13.5mm bands. Of course you need to observe how the shaft is flying and make sure that shaft is totally stable. I am guessing that with 2 x 13.5mm at 380% you should be very close to TV. Of course you need to use very thin line as drag becomes a factor with such light shafts. I recommend the head tennis racket line which is around 1.2mm to 1.3mm. This line has fibers which actually make it extremely strong and very good abrasion resistance for fish up to 10 kg.
As for the Sniper 125 video test ... hmmm that is pretty interesting. The actual distance is probably around 5.15m as I always move a tiny bit back before taking the shot, but I never thought of using video footage to gauge shaft speed ... maybe that is possible. I just use penetration testing at a set distance using the exact same shaft and line ... it does not give absolute data points but it gives a general idea of how fast shaft is moving. By the way, in the Sniper 125 test, I had much better results with a 7.5mm shaft over the 8mm shaft ... my guess is with an 8mm shaft the 14.5mm bands cannot power the shaft to TV (although still very fast). But with a 7.5mm shaft the performance was pretty incredible with extremely flat shooting and very high penetration on target. Maybe there is a way to get more performance out of an 8mm shaft with that configuration by finding a way to add a 3rd band where it will not interfere with the 2 bands, but that needs a re-think on how to have the bands lay on the gun. As it is ... with 2 bands and an 8mm shaft, you pretty much have most of the fish in the ocean covered up to 5m or even 6m. |
09-13-2019, 06:48 AM | #10 |
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Re: 14 or 14,5mm bands for 100-105 cm spears?
You can def count frames - or even sound - to get an average shaft speed. Many has done it before. I recall a Russian/Ukranian bunch of spearos did it for pool testing short pneumatics and maybe also some did it in the Med. Perhaps the "standard" was set a 4m. I did it once with an older 90cm airgun but can't find the results any longer:-(
But of course, it's an extra setup for the camera angle. Now, that many folks have a gopro, it would be a fairly easy test to compare between spearos all over the world:-) Last edited by Diving Gecko; 09-13-2019 at 07:04 AM. |
09-13-2019, 06:59 AM | #11 | ||||
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Re: 14 or 14,5mm bands for 100-105 cm spears?
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A 100 cm, 7mm spear is also 300 grams, and a 105 cm spear is 310-315 grams. I hope to retain most of the power by keeping the mass the same. That is also why I think 14mm rubbers will be the best fit. But im not sure. My biggest fear is that a spear that short will never be stable. What do you think? Quote:
So I think I will have to find a shop where I can get them in my hands and feel them before i buy. Quote:
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A speed test of a 120-130 invert roller would also be very interesting *wink* *wink*. |
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09-13-2019, 07:08 AM | #12 |
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Re: 14 or 14,5mm bands for 100-105 cm spears?
I think you might have gotten unlucky with the tennis line - I ordered a handful of samples in China and most of them were really supple with way less memory than the hailed Triple Ace mono, even the ones with some fiber stuff in them. I had a really cool silvery one for a while. But yes, some pro shop where they string rackets would be cool to check out.
Last edited by Diving Gecko; 09-13-2019 at 08:03 AM. |
09-13-2019, 07:25 AM | #13 | |
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Re: 14 or 14,5mm bands for 100-105 cm spears?
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09-13-2019, 07:52 AM | #14 |
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Re: 14 or 14,5mm bands for 100-105 cm spears?
Damn, I just lost a whole post.
Anyways, I was saying perhaps it would make more sense that we switch to m/sec. You probably did the 'time to reach 1m' as the distances differ between the tests you could find. It's just that distance/time is more of a standard. Ideally, in the future people could settle on, say, a 4m standard Lamberto's video (misc. pulley rollers): 1m in 56.6msec = 17.7m/sec (3m distance) Majd's video: 1m in 46.6msec = 21.5m/sec (5m distance) Now, I can't add much as I only have one old video where I don't even know the distance to target, so the best I could do was to count frames until the line was pulled tight and knowing the line length I came up with a meager 14m/sec. BUT this was for a tiny 7mm x 84cm airgun shaft (app. 260g) at a long 5.5m (after going through a water bottle target)... So, 14m/sec over the course of 5.5m leaves me with very little doubt I would have beaten the pulley rollers (17.7m/sec) had I measured at 3m;-) As a bit of an aside, Dima claims his tuna gun to be shooting a 9mm x 150cm shaft a 49m/sec but I think that was measured at perhaps 2-3m? But he also states that is is Vmax (max speed). And on the Russian forums they sometimes state that the most efficient airguns can shoot at around 30m/sec but I don't know if what distance they measure at or whether that is "just" a calculated value. Last edited by Diving Gecko; 09-13-2019 at 11:09 AM. |
09-13-2019, 09:25 AM | #15 |
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Re: 14 or 14,5mm bands for 100-105 cm spears?
Some years ago there was a cold water band rubber made for ice diving which was compounded for that particular application, but I have not heard of it since. Some hydropneumatic guns can freeze up when the gun shoots, rapidly expanding air in the gun sucks in heat and in icy waters it freezes the water in the gun's valve operated trigger system. Mechanical sear tooth guns don't have that problem, but the valve hydro guns do and you have to heat the gun up to get the ice out or your spearfishing session is over.
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