Спасибо громадное! Одно из лучших видео данной тематики, какие я смотрел! Все очень понятно, великолепная работа камеры и умное объяснение! Еще раз спасибо!
The best solutions are the simpliest. Engineers point of view. I'll go with the traditional speargun. Simple. Straightforward. Less points of failure. Just more rubberband for more power.
Just more rubber band for more power, exactly and more smooth more accurate perhaps you didn't listen and secondly the more power you got better chance of not losing the fish of a life time, if you like your system you have better you stay with it , not every one is basic, less recoil more accurate plus power , longer shots better catch rate as well, there is always a reason for engineering improvement otherwise you would not have the basic gun you have instead you would be throwing a sharpened stick by hand instead of having a spear gun that you call basic . from an engineering point of view.
Thanks! Very good presentation! My main concern is a dumper (place where pulling line stops)! It should be most stressful part of the construction... ;-)
Are you speaking of a demultiplied or invert roller? There is a lot of confusion on the matter on the Internet... I have seen system called in miriads of ways, most of them wrong, especially in the US where it looks that they are still struggling with the definition of "kilometer" :-/
Thanks. Roller guns are those where the rubber is in a single stretch and roll around the sheaves. The Fusion has replaced with a line the part of rubber that in a roller goes around the sheaves. The main reason is that the Fusion can have a pre-load of 200% versus the 150% max of a Roller. To get a similar pre-load, the roller should become an invert-roller that includes another pair of sheaves near the handle. Yes it can be confusing with the naming of the various types: Americans are at least 30 years late on speargun innovation (just look at the rubbish sold overseas) and since they discovered the "wheeled systems" they are naming all wrong creating confusion... unfortunately the internet speaks Yankee I'm not writing about pneumatic spearguns because I don't know enough about it
@@ragnaroksub1442 Thank you very much. Pneumatic need this handle and to difficult to reload inside water I guess. I do not want to spend a fortune and 150% sounds more than enough. Do you recommend SALVIMAR ? I dream of andanamen sea ...
The whole point in roller guns is to use the length of the rubber from a normal gun for acceleration, and not just stop accelerating before the spear is all out. In this fusion design the upper band still stops before the spear is all out. So how exactly is that helpfull? Just asking from an engineering perspective.
Not exactly. Tests made with high-speed cameras show clearly that the hydraulic losses in the rubber (elastomers behave partially as liquids) cause a slow-down of the rubbers in a roller. This make the wishbone speed topping at around 3/4 of the barrel... definitely more efficient than a standard circular rubber but less effective than a Fusion despite the loss of "barrel lenght". We tested it several years ago with 100 fps... nowadays the new 240fps cameras will be even clearer. Furthermore, the real difference-maker between roller and roller or roller-fusion or whatever, is the less visible pre-stretch: if you have a roller, try two sets of rubbers with the same final elongation but different pre-stretch%... The pre-stretch change completely the K equation raising the start point and increasing greatly the integral of the K(lenght) available to the wishbone point. Basically, higher is the pre-stretch, more is the kinetic energy that is transfer to the spear: the same principle is applied to pneumatic spearguns, and is the reason for the need of high pressure in the tube.
@@ragnaroksub1442 OK i made a little bit of research. So let's take for example a 90cm speargun. We have 90cm to accelerate our shaft as much as we can. Using a pair of 30cm rubbers on a classic gun stretched at 300%, acceleration occurs only at 200%-300% elongation because water resistance, friction and other losses. Our usable acceleration length then would be 30cm. In the most efficient scenarion we would like to have a prestretched band of 90cm at 200%, in order to accelerate the shaft for the whole distance of 90cm, but that would need a length of 270cm rubber. Using roller guns we use band lengths that would normally fit into a longer speargun. A classic roller has long rubber but great losses from the bands on the pulleys, an inverted roller has losses on the pulleys and is not using the bands at their sweet spot (200-300%). A fusion setup on a 90cm speargun would have a 30cm bottom band prestretched at 200% and a 20cm upper band with no prestretch. That's a usable accelerating force length of 50cm that normally a 150cm gun would use. Hope this view is better than my previous. :) Thanks for your reply
Bom dia . Quer dizer que as borrachas tem que ser exatamente a mesma medida e espessura para que a força, seja igual tanto encima ,quanto embaixo . Essa técnica foi utilizada somente para redução do tamanho ou para ampliação de força? E tem alguma dica que você pode me passar para que eu não cometa algum erro ingenuo, tem algo que seja imprescindível fazer para que funcione. Muito Obrigado
Hi. The Fusion system has positive effects on power, shot speed and accuracy by reducing recoil a lot. The rubbers should be the same on top and bottom: the bottom rubbers should stretch from 200% at rest to 320% loaded. The top rubbers should be cut on the length that allows the top rubbers to reach 320% so you can easily find the length empirically. If you want to be sure to get it right at first run, I suggest you to use original Roisub parts (they invented the Fusion) and avoid the MVD copies, that give only problems. Also for the rubbers, it is much better to buy a ready made kit from Roisub at least for the first time.
Force is measured in Newtons (i.e. kg⋅m⋅s^−2), not kg, that'd be mass. ;) Interesting idea. Bit complicated to set-up. Can this be set-up on any roller speargun (e.g. do you need special rollers for the cord, or can you use rollers designed for rubbers to roll over) - or perhaps any inverted roller speargun?
Yes you are totally right... but if I start also to use N instead of familiar kg it would become a video for the Club of Physics ;-) Yes it can be installed in any head with sheaves... but obviously the efficiency change with friction loss and so on.
Great video sir, I have a quick question tho, compare to a classic single rubber gun, how would you rate the ease of loading it ? Same ? easier ? Harder ? Thank you very much.
The loading force when the rubbers are fully stretched is the same... but a standard speargun starts from 0% until ~320% , while a Fusion starts at 200% until ~320%. In short, it is harder from the beginning... but besides that, it is the same strength that you need to pull it back til the pin.
@@ragnaroksub1442 Thank you for your answer sir. Much appreciated. Is there a chart somewhere where you can get the exact length of each rubber to cut according to the length of the speargun ?
The fusion split the rubbers in two segments (upper and lower), the rubber start from the handle, goes around the head and comes back on the spear. Inverted roller (the classic at least) start from the front, goes around sheaves at the handle, goes back to the head and return with a line. Depending on prestretch, the start point can be moved with another pair of sheaves in the head. Both systems are wildly abused by manufacturers that have few but confused ideas... but when well made, both systems are good... I prefer Fusion because is much more simple.
Are these weapons are meant to be used one handed? If not i don't really understand how do you hold the one with the rollers without you touching the bottom rubbers.
I got that, the part that is unclear is how it's your interaction with the bottom rubber during use. Do you use only one hand aiming? Do you use it whatever you want and if you use two hands the bottom rubber just slides under your hand when it contracts during fire? Do you have to be aware not squeezing to hard? Do you need gloves? How about damage to your palm skin, glove or rubber from long usage? Has that any effect, if you grip the bottom rubbers while aiming, on draw and spear launch and speed?
when you start explaining work as the change in KE and then dumb it all back to "power" lol nice video. One simple question: in comparison to the roller, I understand ur argument of potential energy being lost in the rotation of the pulley as well as friction through it, yet wouldn't you face a similar loss in this system? is the smaller coefficient of friction of the fusion enough to make up for the lack of barrel length used when the top rubber is at rest? My 100 cm roller has 50cm bands, fully stretch. giving me 200% pretension, and 390% loaded. this percentage though, is of a much longer rubber due to the absence of connecting dyneema present on the fusion, providing me with larger potential energy, and a longer acceleration time since the whole barrel is used. I guess my question comes dow to: is the friction reduction enough to justify the less rubber and the less band pull? Great system nevertheless, let me know your thoughts!
this is true, the PE of a spring is a percentual matter! I didn't mean to argue that fact. Though I had never thought about the hydraulic loss as the rubber catches up to itself, cool stuff. maybe ill try one of your systems sometime! thanks for the new knowledge. P.S I obviously use a load assist...
You didn't pre stretch the lower rubber for 200% but only for 100% . 22 cmm to 44 cmm iz 100% more, 200% it would be 66 cm ;-) . BTW thanks for the video, I have been made fusion speargun by my self from traditional speargun. The results are amazig!
The rubber calculation is made including the relaxed lenght... don't ask me why but it is like that. I guess it is because of the ease in the calculations: when a supplier is telling you that the suggested stretch is 310% you just divide the available lenght by 3.1 and get the cut out lenght (and don't forget the extra lenght for the knots 😉). Yes... it is weird but the industry standard is like that.
@@ragnaroksub1442 I have beuchat merlin evil 90, if i want to make fusion, can you suggest the length of the rubber band for both pair? The upper pair and the lower band pair? Thanks in advance Thor!
All sound good and nice, however the system adds bulk to the gun, it makes it more complicated/busy, creates points to get the line tangled and it doubles the maintenance cost (more rubber/line to replace). In addition i don't see the point of having such system on shorter spearguns 60 to 90cm which they're primarily used in shooting fish hiding between and under rocks and from a short distance. A 75-90cm speargun loaded with a single 19mm or 2X14,5mm rubber is more than plenty even against large groupers. Hunting in the open is a different scenario, however i see problems arising there as well.
Boa noite Luiz Do Brasil Achei muito inteligente essa configuração que vocês fez com essa arpão Agora sera que esse modelo poderia funcionar em um rifle estilingue e só para entender a borracha de baixo ela ja fica esticada sempre em 200% e ai estica a superior com mais 250% Obrigado e parabens
Hi, The lower rubbers have to stretch from 200% till 350%, and to achieve that, you will have a fixed length of dyneema line. The top rubbers will need to cover the missing length by stretching at the exact same coefficient as the lower rubbers: if the lower rubbers stretch 350% at maximum, the top rubbers will stretch also at 350%.... being connected and made of the exact same rubber, the force applied will be exactly the same.
Thanks! I've seen this system in a couple videos and wondered how it works. I'm not an expert, but how I understand recoil is the mass and velocity of parts moving forward versus the parts moving backwards. So if the two rubbers under the barrel are heavier, it should reduce the total recoil? Of course the slapping of the rubbers in the muzzle affect vertical accuracy, but I would not call it recoil.
That’s not 100% right…I’m sorry to say… The strength exerted by in an elastic body in deformation is proportional to the deformation (linear, angular or else), that’s why you can’t expect to deform a body, an empty soda can let’s say, with the stored energy in a half way stretched elastic band than with the one stored in a full stretched elastic band… There’s a physical law describing the whole matter…It’s called the Energy’s Conservation Law… Maybe you’ve got all wrong with the total amount of energy in a system which indeed remains the same no matter the deformation unless another force acts in a particular way on/in/over said system.
It is not a matter of the total potential energy stored in the rubbers but how much of it is transferred to the spear and transformed into work... basically we are speaking about system efficiency
One more question, why dont you cut away that top rubber? I think you earn more energy? Or is that rubber for easier loading conditions? Greetings and i would be happy to hear from you
The top rubbers allow a pre-stretch of 200%... it is the key of the system efficiency. Without top rubbers you will have a regular invert that is less powerful than a regular circular mono (but with less recoil of course... that is the reason for the invert)
The secondary recoil is given by the rubbers... not the spear: actually is not a "recoil" but is called like this for simplicity... in reality is the effect of the rubbers hitting the speargun at the end of their contraction.
Super explanation of the advancement. The difference is never really known until you have pulled both triggers. I enjoyed your video, thanks.
30 years in the sea i have never seen something like this. My 82 pathos became a superpower gun. Thank you for your advices.
Спасибо громадное!
Одно из лучших видео данной тематики, какие я смотрел!
Все очень понятно, великолепная работа камеры и умное объяснение!
Еще раз спасибо!
Physics in a simple way!!! well done!!!
That is the best design have ever seen. Thank you for sharing.
how is this better than a normal roller or inverted roller
Your presentations are very good and detailed... very nice
The best presention ever ❤
Very well explained, Thank you for the leason.
the sandow is 16 and the shaft is 6.5 ??
The best solutions are the simpliest. Engineers point of view. I'll go with the traditional speargun. Simple. Straightforward. Less points of failure. Just more rubberband for more power.
Try it first ;-)
Another engineer's point of view ;-)
Engineer's point of view would be to always keep improving, not copy what works alright..
Just more rubber band for more power, exactly and more smooth more accurate perhaps you didn't listen and secondly the more power you got better chance of not losing the fish of a life time, if you like your system you have better you stay with it , not every one is basic, less recoil more accurate plus power , longer shots better catch rate as well, there is always a reason for engineering improvement otherwise you would not have the basic gun you have instead you would be throwing a sharpened stick by hand instead of having a spear gun that you call basic . from an engineering point of view.
@@prins2x Exactly! Good comment!
Thanks! Very good presentation! My main concern is a dumper (place where pulling line stops)! It should be most stressful part of the construction... ;-)
Yes it is... that is why I prefer the Dyneema: it can absorb much more also in the freezing temperatures of the Baltic Sea in the winter.
Invert roller neutralizes primary recoil by throwing the rubbers in the opposite direction from the shaft vector...
Are you speaking of a demultiplied or invert roller? There is a lot of confusion on the matter on the Internet... I have seen system called in miriads of ways, most of them wrong, especially in the US where it looks that they are still struggling with the definition of "kilometer" :-/
where can I buy this gun ? i live in Sydney Australia.
how much it costs?
excellent explanation
Thank you sir.
Well done. Think it is called roller-gun now a days ? When do you make a video about pneumatic one ? Save dives
Thanks. Roller guns are those where the rubber is in a single stretch and roll around the sheaves. The Fusion has replaced with a line the part of rubber that in a roller goes around the sheaves.
The main reason is that the Fusion can have a pre-load of 200% versus the 150% max of a Roller.
To get a similar pre-load, the roller should become an invert-roller that includes another pair of sheaves near the handle.
Yes it can be confusing with the naming of the various types: Americans are at least 30 years late on speargun innovation (just look at the rubbish sold overseas) and since they discovered the "wheeled systems" they are naming all wrong creating confusion... unfortunately the internet speaks Yankee
I'm not writing about pneumatic spearguns because I don't know enough about it
@@ragnaroksub1442 Thank you very much. Pneumatic need this handle and to difficult to reload inside water I guess.
I do not want to spend a fortune and 150% sounds more than enough. Do you recommend SALVIMAR ? I dream of andanamen sea ...
Pathos seems to have a better tracking... At least listening to the guys who tried both.
8:50 - WTF ;-) That is what you want in a speargun!
Band length calculation?
Gd day sir nice presentation how about the pathos sniper roller how much it cost but im in the philippines i would like to buy stuff.
How
Much
Thé
Fusion
Sistem
600 eur without reel and 650 with reel. Same price for lenghts 75-100 cm
Hi,
I have pathos 82 carbon with shaft 7mm can I use this system?
The whole point in roller guns is to use the length of the rubber from a normal gun for acceleration, and not just stop accelerating before the spear is all out. In this fusion design the upper band still stops before the spear is all out. So how exactly is that helpfull? Just asking from an engineering perspective.
Not exactly. Tests made with high-speed cameras show clearly that the hydraulic losses in the rubber (elastomers behave partially as liquids) cause a slow-down of the rubbers in a roller. This make the wishbone speed topping at around 3/4 of the barrel... definitely more efficient than a standard circular rubber but less effective than a Fusion despite the loss of "barrel lenght".
We tested it several years ago with 100 fps... nowadays the new 240fps cameras will be even clearer.
Furthermore, the real difference-maker between roller and roller or roller-fusion or whatever, is the less visible pre-stretch: if you have a roller, try two sets of rubbers with the same final elongation but different pre-stretch%...
The pre-stretch change completely the K equation raising the start point and increasing greatly the integral of the K(lenght) available to the wishbone point.
Basically, higher is the pre-stretch, more is the kinetic energy that is transfer to the spear: the same principle is applied to pneumatic spearguns, and is the reason for the need of high pressure in the tube.
@@ragnaroksub1442 OK i made a little bit of research. So let's take for example a 90cm speargun. We have 90cm to accelerate our shaft as much as we can. Using a pair of 30cm rubbers on a classic gun stretched at 300%, acceleration occurs only at 200%-300% elongation because water resistance, friction and other losses. Our usable acceleration length then would be 30cm. In the most efficient scenarion we would like to have a prestretched band of 90cm at 200%, in order to accelerate the shaft for the whole distance of 90cm, but that would need a length of 270cm rubber. Using roller guns we use band lengths that would normally fit into a longer speargun. A classic roller has long rubber but great losses from the bands on the pulleys, an inverted roller has losses on the pulleys and is not using the bands at their sweet spot (200-300%). A fusion setup on a 90cm speargun would have a 30cm bottom band prestretched at 200% and a 20cm upper band with no prestretch. That's a usable accelerating force length of 50cm that normally a 150cm gun would use. Hope this view is better than my previous. :) Thanks for your reply
Bom dia . Quer dizer que as borrachas tem que ser exatamente a mesma medida e espessura para que a força, seja igual tanto encima ,quanto embaixo . Essa técnica foi utilizada somente para redução do tamanho ou para ampliação de força?
E tem alguma dica que você pode me passar para que eu não cometa algum erro ingenuo, tem algo que seja imprescindível fazer para que funcione.
Muito Obrigado
Hi. The Fusion system has positive effects on power, shot speed and accuracy by reducing recoil a lot.
The rubbers should be the same on top and bottom: the bottom rubbers should stretch from 200% at rest to 320% loaded. The top rubbers should be cut on the length that allows the top rubbers to reach 320% so you can easily find the length empirically.
If you want to be sure to get it right at first run, I suggest you to use original Roisub parts (they invented the Fusion) and avoid the MVD copies, that give only problems.
Also for the rubbers, it is much better to buy a ready made kit from Roisub at least for the first time.
Force is measured in Newtons (i.e. kg⋅m⋅s^−2), not kg, that'd be mass. ;) Interesting idea. Bit complicated to set-up. Can this be set-up on any roller speargun (e.g. do you need special rollers for the cord, or can you use rollers designed for rubbers to roll over) - or perhaps any inverted roller speargun?
Yes you are totally right... but if I start also to use N instead of familiar kg it would become a video for the Club of Physics ;-)
Yes it can be installed in any head with sheaves... but obviously the efficiency change with friction loss and so on.
Great video sir, I have a quick question tho, compare to a classic single rubber gun, how would you rate the ease of loading it ? Same ? easier ? Harder ? Thank you very much.
The loading force when the rubbers are fully stretched is the same... but a standard speargun starts from 0% until ~320% , while a Fusion starts at 200% until ~320%.
In short, it is harder from the beginning... but besides that, it is the same strength that you need to pull it back til the pin.
@@ragnaroksub1442 Thank you for your answer sir. Much appreciated. Is there a chart somewhere where you can get the exact length of each rubber to cut according to the length of the speargun ?
What is the difference between fusion and inverted roller?
The fusion split the rubbers in two segments (upper and lower), the rubber start from the handle, goes around the head and comes back on the spear.
Inverted roller (the classic at least) start from the front, goes around sheaves at the handle, goes back to the head and return with a line. Depending on prestretch, the start point can be moved with another pair of sheaves in the head.
Both systems are wildly abused by manufacturers that have few but confused ideas... but when well made, both systems are good... I prefer Fusion because is much more simple.
@@ragnaroksub1442 Thank you! Finally I understand it! 👍🏽
Are these weapons are meant to be used one handed? If not i don't really understand how do you hold the one with the rollers without you touching the bottom rubbers.
I got that, the part that is unclear is how it's your interaction with the bottom rubber during use. Do you use only one hand aiming? Do you use it whatever you want and if you use two hands the bottom rubber just slides under your hand when it contracts during fire? Do you have to be aware not squeezing to hard? Do you need gloves? How about damage to your palm skin, glove or rubber from long usage? Has that any effect, if you grip the bottom rubbers while aiming, on draw and spear launch and speed?
one handed
Website not found.
Can you please attach a new link
Thanks
www.roisub.net/
when you start explaining work as the change in KE and then dumb it all back to "power" lol nice video. One simple question: in comparison to the roller, I understand ur argument of potential energy being lost in the rotation of the pulley as well as friction through it, yet wouldn't you face a similar loss in this system? is the smaller coefficient of friction of the fusion enough to make up for the lack of barrel length used when the top rubber is at rest? My 100 cm roller has 50cm bands, fully stretch. giving me 200% pretension, and 390% loaded. this percentage though, is of a much longer rubber due to the absence of connecting dyneema present on the fusion, providing me with larger potential energy, and a longer acceleration time since the whole barrel is used. I guess my question comes dow to: is the friction reduction enough to justify the less rubber and the less band pull?
Great system nevertheless, let me know your thoughts!
this is true, the PE of a spring is a percentual matter! I didn't mean to argue that fact. Though I had never thought about the hydraulic loss as the rubber catches up to itself, cool stuff.
maybe ill try one of your systems sometime!
thanks for the new knowledge.
P.S I obviously use a load assist...
Excelente tapón amigo como me gustaría comprarle uno soy Andrés de Ecuador un gusto saludarle amigo
How can I buy one do you have a link to shop
Right now they have it at Kingfish.dk with 20% discount (disc. code: BRUGNATUREN20): www.kingfish.dk/ragnarok-diablo-fusion-k2
You didn't pre stretch the lower rubber for 200% but only for 100% . 22 cmm to 44 cmm iz 100% more, 200% it would be 66 cm ;-) . BTW thanks for the video, I have been made fusion speargun by my self from traditional speargun. The results are amazig!
The rubber calculation is made including the relaxed lenght... don't ask me why but it is like that.
I guess it is because of the ease in the calculations: when a supplier is telling you that the suggested stretch is 310% you just divide the available lenght by 3.1 and get the cut out lenght (and don't forget the extra lenght for the knots 😉).
Yes... it is weird but the industry standard is like that.
@@ragnaroksub1442 boss saya mau pesan gimana caranya n harganya berapavRp?
@@ragnaroksub1442 I have beuchat merlin evil 90, if i want to make fusion, can you suggest the length of the rubber band for both pair? The upper pair and the lower band pair? Thanks in advance Thor!
Can you add a kicker band?
In Scandinavia the shot will be different than in Hawai... donºt forget the water temperature will affect the rubbers ;)
All sound good and nice, however the system adds bulk to the gun, it makes it more complicated/busy, creates points to get the line tangled and it doubles the maintenance cost (more rubber/line to replace). In addition i don't see the point of having such system on shorter spearguns 60 to 90cm which they're primarily used in shooting fish hiding between and under rocks and from a short distance. A 75-90cm speargun loaded with a single 19mm or 2X14,5mm rubber is more than plenty even against large groupers. Hunting in the open is a different scenario, however i see problems arising there as well.
Just try
Boa noite Luiz Do Brasil
Achei muito inteligente essa configuração que vocês fez com essa arpão
Agora sera que esse modelo poderia funcionar em um rifle estilingue e só para entender a borracha de baixo ela ja fica esticada sempre em 200% e ai estica a superior com mais 250%
Obrigado e parabens
Hi,
The lower rubbers have to stretch from 200% till 350%, and to achieve that, you will have a fixed length of dyneema line.
The top rubbers will need to cover the missing length by stretching at the exact same coefficient as the lower rubbers: if the lower rubbers stretch 350% at maximum, the top rubbers will stretch also at 350%.... being connected and made of the exact same rubber, the force applied will be exactly the same.
Do you still make these?
Yes but only on order... carbon version.
Minta tutorialnya
What is the size is that gun?
It say 60 on the barrel, so 60cm
thank you ! very good video ,
wow super amazing.
Thanks! I've seen this system in a couple videos and wondered how it works.
I'm not an expert, but how I understand recoil is the mass and velocity of parts moving forward versus the parts moving backwards. So if the two rubbers under the barrel are heavier, it should reduce the total recoil?
Of course the slapping of the rubbers in the muzzle affect vertical accuracy, but I would not call it recoil.
That’s not 100% right…I’m sorry to say… The strength exerted by in an elastic body in deformation is proportional to the deformation (linear, angular or else), that’s why you can’t expect to deform a body, an empty soda can let’s say, with the stored energy in a half way stretched elastic band than with the one stored in a full stretched elastic band… There’s a physical law describing the whole matter…It’s called the Energy’s Conservation Law… Maybe you’ve got all wrong with the total amount of energy in a system which indeed remains the same no matter the deformation unless another force acts in a particular way on/in/over said system.
It is not a matter of the total potential energy stored in the rubbers but how much of it is transferred to the spear and transformed into work... basically we are speaking about system efficiency
One more question, why dont you cut away that top rubber? I think you earn more energy? Or is that rubber for easier loading conditions?
Greetings and i would be happy to hear from you
German Spearfishing Channel the ruber is for easier loading
German Spearfishing Channel and for more grip
Very good question...
German Spearfishing Channel If you have the top rubber you have just a litle more power. The best guns are inverted rollers!
The top rubbers allow a pre-stretch of 200%... it is the key of the system efficiency.
Without top rubbers you will have a regular invert that is less powerful than a regular circular mono (but with less recoil of course... that is the reason for the invert)
Can i buy spear gun
You are wrong with the "secondary recoil". The shaft has already left the track at that time.
The secondary recoil is given by the rubbers... not the spear: actually is not a "recoil" but is called like this for simplicity... in reality is the effect of the rubbers hitting the speargun at the end of their contraction.
good job i think
Exelente
From where I can buy this system ?
did he just swear? hahaha
Wow amezing give me sir 😊🤣
I like in
I like in