Thanks Uncle Rob. I got a 90 cm Tuna Roller gun. Put a 14 mm rubber on it and double wrapped it. It shoots like a dream. I always adore your spearguns. The only brand I ever used. I have a question, for a blue water environment (chasing tuna, wahoo etc), would you still recommend a 110 cm length still? I'm thinking of getting a 120 cm Carbon GT Roller for blue water. Thanks, Uncle Rob :-) Greetings from Australia.
It's always very interesting to watch you short and helpful clips. In this video, for me interesting, how to do up bands specially for roller gun, I mean extra rope for loading. Thanks:)
Aloha Rob. Appreciate your informative videos. Question on roller band wishbones. What is the purpose of the two same size wishbones? Do you double them up on the notch or just hook one so the other hits muzzle and doesnt kick shaft up? Thank you 🤙🏾
There used to be wear that occurred on the wishbone line so we saw guys doubling up on these. We eventually worked out, this was due to the shooting line being pulled over the top and in front of the wishbone during the shot. Once the spear started to pull out the shooting line it would have to be dragged back around and under. You would not see this unless watched after videoing and slowing down the frame rate. We realized the problem was caused mainly due to over-powering the gun. We have since sorted this by setting the power/speed of the spear to just reach max as it exits the muzzle. This eliminates 98% of the wear. The double wishbone is a carry over from that and the general market still want it. Not a good idea to try fit both into the wishbone slot as they both will not fit. If you try, the one will go in and the 2nd will get cut/damaged on the sharp edge of the wishbone notch.
@RobAllenSpearfishing Thanks Rob. I made a band with a double uneven wishbone to try, but I'll definitely make sure I tighten up the shooting line. Just bought your 110 single roller and swapped shaft and rubber for 7mm and 14mm, for more reef shooting. Anxious to get back in the water and try it out. Only took two shots before that and they both dove low (but I did have a non tight shooting line). Thank you for your response. Aloha 🤙🏾 🤙🏾
Great video Rob , thanks!! You say in the video that to calculate the size of the rubbers, we make half the tube + 10cm for 16mm rubbers. Is the formula the same for 14mm rubbers? Is it really half of the tube, or half from the head to the last notch? I have: Tube = 83cm Head/Notch=92cm you say it should have a pretension of 19/20kg for 16mm rubber, it should have between 10/15kg for 14mm? as I said in a previous answer in another video? thank you very much! Greetings from Portugal.
Yes, same for 14mm. We use half our barrel length + 10cm. You can always make it a little longer as you can shorten but not make it longer. Yes, 10 to 15kg for 14mm. Start out at +- 10kg, you can always shorten.
Could you do a video on band choice for different purposes for your rollerguns? I have your 90 cm roller and have tried it with different bands configurations with your 6.6 mm 120 cm spear. I am hunting small and fast fish (trout) so my goal is the fastet shot with minimal drop and recoil - for fast twict instinctive shooting. Penetration is not an issue, since the biggest fish are usually 8 kg. I have tried both your 14mm and 16mm bands cut to your recommendation - half barrel length + 10 cm = 55 cm total but also shortend to 50 cm. I dont have the facilities to pooltest, but my initial impressions are that the 16mm cut to 50cm deliver the best speed with minimal drop but a little recoil, which I can handle. I would like to hear more about your testing results and your thoughts about recommendations for band choice for your great rollers. Again - thanks for the great videoes.
Hi Martin, We have not had great success with 6,6mm spears on rollers as they don't seem to have sufficient weight/mass to shoot to the end of double wrap line. If you are able to use a 16mm rubber with a 6,6mm spear, it could be because the water is cold. Rubbers lose its elasticity the colder the water is.
@@RobAllenSpearfishing Thanks for answering so quickly! Very interesting - the water temps have been around 14-18C, I suspect this qualifies as "cold" compared to South Africa ;) Clearly there is lots to be learned - this begs for more videoes on the subject. I hope you will do an in-depth video(s) explaining pros and cons of different setups on these rollerguns and your learnings from testresults and experience in general.
@@RobAllenSpearfishing Oh you don't have to do that 😅🥶 It could just be a video with a discussion of your test results and experiences so far - you have a lot already It seems 🤙🙂
Hey Rob great video. Question though, I have seen guys not placing the loops at the end of the rubber around the anchor points, istead they use another length of dyneema connecting the loops and this goes around the anchor points and under the barrel. The rubbers are then half the barrel length. Advantages/disadvantages of this and do you recommend it? I can only think that it would make it easier and faster to adjust pre tension on the go rather than having to cut the rubbers.. Thanks for your time
In pool testing, the shorter the roller the more the advantage when comparing it to a standard double 16mm gun. As the rollers get longer, the advantage in terms of power (spear penetration) accuracy, reduces. We found at 130cm, a single 16mm powered roller has the same power (spear penetration) as that of a 130cm double 16mm rubber gun with double wrap. Only advantage is that the recoil is reduced. This is why we try to recommend not going longer than a 110cm roller.
@@martincjoergensen The standard gun will not be as strong as a roller in that length. Most standard guns are single wrapped with sufficient power and accuracy to the end of their single wrap. The 80cm roller will still be good to the end of the double wrap. A single can shoot 5 X the barrel length and the roller with double wrap 7 x barrel length.
Hey Rob, if I would like to convert my Scorpia 700 (non rail) with 6.3 mm spear to roller, what bands should I use and should I change the barrel and spear too?
Roller guns work best with a 7mm or 7,5mm spear on a rail barrel. You would be changing everything but the handle. Better to keep the Scorpia as a 2nd gun and buy a roller to what ever set up you want.
Should be fine. Only issue is if the water is very cold, it will reduce the band performance equally no matter what band gun you use. Generally guys cut the bands shorter when using band guns in cold water.
I notice you do sell these up to 130 cm. What happens at 110 cm that makes it not worth it to go bigger? In an extreme example of a 150 cm gun, what happens that makes it not beneficial to convert to roller? Is it just too hard to load? Would a 150 cm single roller be less powerful than a double standard band? Love your gear, and thanks for making these videos.
We tested up to a 130cm roller against same size guns with double rubbers. As mentioned before, the advantage was big at the shorter gun lengths but, slowly this advantage diminished. At 130 both were equal in power and accuracy when both were double wrapped. We did not test longer because we assumed it would get worse and, as you pointed out, loading would become very difficult. Our thoughts are, on the shorter guns the length of stroke with rollers when comparing was much greater. As the guns got longer, the longer guns rubber stroke lengths got better. Look at the ratio of spear ahead of the rubbers on a non roller gun compared to what is behind. The rubber has only a short stroke to power up the spear. The longer the gun, the longer that stroke ratio becomes.
Understood, thanks for the reply, and that makes sense regarding the ratio. Only asking asking because I have the 150 tuna with 7.5 mm shaft and was considering putting a roller muzzle on it. Even if I could only get equal power, it think it would be worth it for the reduced recoil.
Dear Rob, my roller head seems having got some sand jammed in the ceramics bearing and when I spin the bearing, I can hear sands friction sound and not as smooth as when it was new. Any tips of how can resolve this? Thanks, Rui
Have you tried running it under running hot water? Normally ceramic is harder than sand so it crushes it up and all comes right. Sometimes dried salt water can sound like this but hot water melts it out.
@@RobAllenSpearfishing thanks Rob for your reply. I found that issue as soon as I went out of water from shore. Having tried to wash it in hot water also for half an hour. I'm pretty sure it's not salt. I'll try to spin the ceramics to crush the sands off. It's my secondary time to use the roller and I think it might not good for shore dive because it's getting in sand too easy. I'm using a 80cm carbon RA roller by the way. It's a bit heavy in the water and easy to sink to the bottom, and I think that's how it's got sands in. Kind Regards, Rui
@@ruitian8724 Yes the shorter gun do have a buoyancy problem. The 900 is only just buoyant. We are working on reducing the muzzle weight by using a smaller axle and smaller bearings. These have been tested now for a year and so far all good. We are also working on adding timber side stocks but to glue them well is difficult. Better to have them attached to raw carbon. Regarding the sand, some have had success by dissembling all and trying to get the sand out with the bearing fully open. Just be careful not to loose the screws.
Thanks for the advice. Does it degrade the bands if stored indoors but under normal indoor light from windows and artificial light but no direct sunlight , do we have to keep them in a dark closet for example?
Rob, big fan here. I have your 1200 Tuna Railgun. It comes with two bands. How does the performance compare from the stock setup to switching to the single roller?
Hi Scott, the same set up (gun length and spear diameter will be better with a roller muzzle but not as big a difference when comparing a shorter gun. At about 1,3m there is not much advantage in power but there is much lower recoil. Some guys have problems with accuracy due to the recoil and a roller muzzle will help with this.
Very interesting video. You mention the impact of temperature on the rubbers. I live in Denmark and often hunt in waters around 0-8 degrees. How do cold temperatures impact the rubbers? Since things often contract when getting colder, my intuition tells me to cut the rubbers a bit longer than normal - but what do you think?
The reverse. The warmer the water the better the rubber works. It is easy to cut the rubbers too short and over power a gun in warm water because the warmer the rubber the better the elastic return is. So, in colder water, the rubbers perform poorly, shorter is therefore better.
Hi Bruce, I will try do one when the factory fully opens. Pretty simple though, change the roller, drill out the handle screws and fit the rubber anchors. Cut and set the rubbers as explained in this video.
@@RobAllenSpearfishing Always sensible and perfect advice. Challenge is stainless anchors nowhere available. Likewise Rob Allen master class spearguns. So SALVIMAR it is then.;-(((((
Just bought the tuna roller 90 cm. Insaine power and precision - very nice. It is quite heavy in the water though. Rob, do you know if the gun will be close to neutral buoyant if I replace the aluminium tube with your carbon tube? Best regards from Denmark.
@@RobAllenSpearfishing Do you know what the weight difference is between your 90 cm rail tube in aluminium and carbon? Then I can better guestimate the effect on buoyancy.
@@martincjoergensen I can give you the barrel differences. We have a standard aluminium (1,45mm wall) A 90cm barrel will weigh 385,1 grams. The same aluminium (1mm wall, same OD) is 306,9 grams. The carbon 90cm is 266,3 grams. The carbon dimensions are exactly the same as the 1,45mm aliminium barrel.
By half the rubber length plus 10 cm do you mean if its a 90 cm gun my 16 mm rubbers should be 50 cm? Does it hold the same for 14mm rubbers? Chris coats in his article tends to favor the 14mm for hand loadable shorter rollers.
Half of 90 is 45, plus 10 = 55cm. This is a good start. At 50cm it will work if the pre-load is 25kg or less. Yes, 14mm works to the same ratio but will give slightly less pre-load. Remember the 14mm rubbers will be best for 7mm spears.
Sorry we do but only to our distributor there. Fa’nu’i 570B West Marine Corps Drive Anigua 96932 Guam P: +16714826011 T: +16714776011 E:fanuiguam@gmail.com
@@roballen1578 Thank You sir! Appreciate the Reply! Love the videos and Gear! Will check him out asap! Guam 🇬🇺 Loves Rob Allen Si yu'os Ma'ase (Thank you) in Chamorro
RobAllenSpearfishing oh I though it was the ex carbon GT roller.. which I purchased second hand and was wandering if there is any difference than the limited edition GT roller?
hello rob , im having problem on on my tuna railgun converted to roller, how long is the wishbone needed to be it seems like its still on the notch as it goes to the railing of the roller? its shooting downwards or could it be the recoil from the gun tipping the end of my spear?
There are many possibilities. What length gun is it? What shooting line are you using? What roller did you fit? Rollers can be very tricky. The biggest problem is not tightening the shooting lines properly. If it is slack it can get sucked into the roller then get pulled out, jerking the shooting line and affecting the spear flight.
@@roballen1578 @Rob Allen my gun is 900 railgun and i bought rob allen roller kit and im using a 2mm dyneema. i have my bands at 55 cm . should i try go 1.8mm dyneema? my shootingline has tension with my bungee but ill try and make it a little more tighter
Great video, as always. I have a 140 tuna double 16mm rubbers. I'm considering to convert it to a double roller and to use twin 14mm roller rubers to hunt large pelagic fish like wahoo and sailfish. Do you think that this could improve the gun's range and accuracy? I'm thinking of a coatesman double roller head. Thank you
my roller head still does not spin nice and freely, even after applying water and rinsing it. do you recommend taking it apart? or getting a part replaced?
I have the same problem, one not spinning freely. Ive spent a lot of money on ceramic skateboard bearing over the years so I've been super cautious in taking care of these bearings, washed in fresh water after each use. Ive bought two of these because I love my 100 roller conversion and I want to do a 120 in the future. Not sure if I should take it apart or take it back to the shop....??
It all depends on your needs. Keep in mind, rollers are way more powerful and are double wrapped. A 1.1m will shoot as far as a 1,3m double rubber normal gun.
Thanks Uncle Rob. I got a 90 cm Tuna Roller gun. Put a 14 mm rubber on it and double wrapped it. It shoots like a dream. I always adore your spearguns. The only brand I ever used.
I have a question, for a blue water environment (chasing tuna, wahoo etc), would you still recommend a 110 cm length still? I'm thinking of getting a 120 cm Carbon GT Roller for blue water. Thanks, Uncle Rob :-) Greetings from Australia.
It's always very interesting to watch you short and helpful clips. In this video, for me interesting, how to do up bands specially for roller gun, I mean extra rope for loading. Thanks:)
We will put one up.
No questions.. Thank you so much..
First from the Philippines
Great tips as usual Rob, aloha and mahalos from Hawaii!
👍👍
Um dia ainda vou conseguir comprar uma Rob Allen , as melhores arbaletes que existe 🙌🙏
Very informative, thanks for sharing
Great advice to check rubbers with a scale. So simple. Never thought about that. Thanks for sharing! >
Aloha Rob. Appreciate your informative videos. Question on roller band wishbones. What is the purpose of the two same size wishbones? Do you double them up on the notch or just hook one so the other hits muzzle and doesnt kick shaft up? Thank you 🤙🏾
There used to be wear that occurred on the wishbone line so we saw guys doubling up on these. We eventually worked out, this was due to the shooting line being pulled over the top and in front of the wishbone during the shot. Once the spear started to pull out the shooting line it would have to be dragged back around and under. You would not see this unless watched after videoing and slowing down the frame rate. We realized the problem was caused mainly due to over-powering the gun. We have since sorted this by setting the power/speed of the spear to just reach max as it exits the muzzle. This eliminates 98% of the wear. The double wishbone is a carry over from that and the general market still want it. Not a good idea to try fit both into the wishbone slot as they both will not fit. If you try, the one will go in and the 2nd will get cut/damaged on the sharp edge of the wishbone notch.
@RobAllenSpearfishing Thanks Rob. I made a band with a double uneven wishbone to try, but I'll definitely make sure I tighten up the shooting line. Just bought your 110 single roller and swapped shaft and rubber for 7mm and 14mm, for more reef shooting. Anxious to get back in the water and try it out. Only took two shots before that and they both dove low (but I did have a non tight shooting line). Thank you for your response. Aloha 🤙🏾 🤙🏾
@@cyosh345 Definitely a good idea to keep that top shooting line as tight as possible, Good luck.
Great Video! Thank you for the info. Where could I buy/find the stainless steel band anchors? Cant find them!!!!
Where do you live?
RobAllenSpearfishing Miami FL
Great video Rob , thanks!!
You say in the video that to calculate the size of the rubbers, we make half the tube + 10cm for 16mm rubbers.
Is the formula the same for 14mm rubbers?
Is it really half of the tube, or half from the head to the last notch?
I have:
Tube = 83cm
Head/Notch=92cm
you say it should have a pretension of 19/20kg for 16mm rubber,
it should have between 10/15kg for 14mm?
as I said in a previous answer in another video?
thank you very much!
Greetings from Portugal.
Yes, same for 14mm. We use half our barrel length + 10cm. You can always make it a little longer as you can shorten but not make it longer. Yes, 10 to 15kg for 14mm. Start out at +- 10kg, you can always shorten.
Could you do a video on band choice for different purposes for your rollerguns? I have your 90 cm roller and have tried it with different bands configurations with your 6.6 mm 120 cm spear. I am hunting small and fast fish (trout) so my goal is the fastet shot with minimal drop and recoil - for fast twict instinctive shooting. Penetration is not an issue, since the biggest fish are usually 8 kg. I have tried both your 14mm and 16mm bands cut to your recommendation - half barrel length + 10 cm = 55 cm total but also shortend to 50 cm. I dont have the facilities to pooltest, but my initial impressions are that the 16mm cut to 50cm deliver the best speed with minimal drop but a little recoil, which I can handle. I would like to hear more about your testing results and your thoughts about recommendations for band choice for your great rollers. Again - thanks for the great videoes.
Hi Martin, We have not had great success with 6,6mm spears on rollers as they don't seem to have sufficient weight/mass to shoot to the end of double wrap line. If you are able to use a 16mm rubber with a 6,6mm spear, it could be because the water is cold. Rubbers lose its elasticity the colder the water is.
@@RobAllenSpearfishing Thanks for answering so quickly! Very interesting - the water temps have been around 14-18C, I suspect this qualifies as "cold" compared to South Africa ;) Clearly there is lots to be learned - this begs for more videoes on the subject. I hope you will do an in-depth video(s) explaining pros and cons of different setups on these rollerguns and your learnings from testresults and experience in general.
@@martincjoergensen One day maybe. Most of our testing is in 27 deg+ water tamp. It's winter now and will try get my guys in the 17 def water 😜👍
@@RobAllenSpearfishing Oh you don't have to do that 😅🥶 It could just be a video with a discussion of your test results and experiences so far - you have a lot already It seems 🤙🙂
@@martincjoergensen We really need to do a temp comparison. Problem is, I need a cold pool and a heated pool to try the same gun the same day 😎👍
Hey Rob great video. Question though, I have seen guys not placing the loops at the end of the rubber around the anchor points, istead they use another length of dyneema connecting the loops and this goes around the anchor points and under the barrel. The rubbers are then half the barrel length.
Advantages/disadvantages of this and do you recommend it?
I can only think that it would make it easier and faster to adjust pre tension on the go rather than having to cut the rubbers..
Thanks for your time
The tests we have done show the more rubber area to stretch the better, provided you get the per-tension right.
Thank you!
Thank you Rob, nice and interesting video ! Do you have a study of impact spears for your tuna guns (110-140) between 2x16mn and 16m roller ? BR. JCF
In pool testing, the shorter the roller the more the advantage when comparing it to a standard double 16mm gun. As the rollers get longer, the advantage in terms of power (spear penetration) accuracy, reduces. We found at 130cm, a single 16mm powered roller has the same power (spear penetration) as that of a 130cm double 16mm rubber gun with double wrap. Only advantage is that the recoil is reduced. This is why we try to recommend not going longer than a 110cm roller.
@@RobAllenSpearfishing interesting. How does a 80cm roller compare to a 80cm standard gun with 2*16mm rubbers?
@@RobAllenSpearfishing Thank you this is very interesting
@@martincjoergensen The standard gun will not be as strong as a roller in that length. Most standard guns are single wrapped with sufficient power and accuracy to the end of their single wrap. The 80cm roller will still be good to the end of the double wrap. A single can shoot 5 X the barrel length and the roller with double wrap 7 x barrel length.
Hey Rob, if I would like to convert my Scorpia 700 (non rail) with 6.3 mm spear to roller, what bands should I use and should I change the barrel and spear too?
Roller guns work best with a 7mm or 7,5mm spear on a rail barrel. You would be changing everything but the handle. Better to keep the Scorpia as a 2nd gun and buy a roller to what ever set up you want.
@@RobAllenSpearfishingThanks for the advice! Best regards :)
Hey Rob, How do these guns perform New England waters?
Rob Robison
Should be fine. Only issue is if the water is very cold, it will reduce the band performance equally no matter what band gun you use. Generally guys cut the bands shorter when using band guns in cold water.
I notice you do sell these up to 130 cm. What happens at 110 cm that makes it not worth it to go bigger? In an extreme example of a 150 cm gun, what happens that makes it not beneficial to convert to roller? Is it just too hard to load? Would a 150 cm single roller be less powerful than a double standard band? Love your gear, and thanks for making these videos.
We tested up to a 130cm roller against same size guns with double rubbers. As mentioned before, the advantage was big at the shorter gun lengths but, slowly this advantage diminished. At 130 both were equal in power and accuracy when both were double wrapped. We did not test longer because we assumed it would get worse and, as you pointed out, loading would become very difficult. Our thoughts are, on the shorter guns the length of stroke with rollers when comparing was much greater. As the guns got longer, the longer guns rubber stroke lengths got better. Look at the ratio of spear ahead of the rubbers on a non roller gun compared to what is behind. The rubber has only a short stroke to power up the spear. The longer the gun, the longer that stroke ratio becomes.
Understood, thanks for the reply, and that makes sense regarding the ratio. Only asking asking because I have the 150 tuna with 7.5 mm shaft and was considering putting a roller muzzle on it. Even if I could only get equal power, it think it would be worth it for the reduced recoil.
Dear Rob, my roller head seems having got some sand jammed in the ceramics bearing and when I spin the bearing, I can hear sands friction sound and not as smooth as when it was new. Any tips of how can resolve this? Thanks, Rui
Have you tried running it under running hot water? Normally ceramic is harder than sand so it crushes it up and all comes right. Sometimes dried salt water can sound like this but hot water melts it out.
@@RobAllenSpearfishing thanks Rob for your reply. I found that issue as soon as I went out of water from shore. Having tried to wash it in hot water also for half an hour. I'm pretty sure it's not salt. I'll try to spin the ceramics to crush the sands off. It's my secondary time to use the roller and I think it might not good for shore dive because it's getting in sand too easy. I'm using a 80cm carbon RA roller by the way. It's a bit heavy in the water and easy to sink to the bottom, and I think that's how it's got sands in. Kind Regards, Rui
@@ruitian8724 Yes the shorter gun do have a buoyancy problem. The 900 is only just buoyant. We are working on reducing the muzzle weight by using a smaller axle and smaller bearings. These have been tested now for a year and so far all good. We are also working on adding timber side stocks but to glue them well is difficult. Better to have them attached to raw carbon. Regarding the sand, some have had success by dissembling all and trying to get the sand out with the bearing fully open. Just be careful not to loose the screws.
@@RobAllenSpearfishing ah, thanks for your kind guidance!
@@ruitian8724 You are welcome.
Thanks for the advice. Does it degrade the bands if stored indoors but under normal indoor light from windows and artificial light but no direct sunlight , do we have to keep them in a dark closet for example?
A dark, cool location is best. I did hear UV from florescent lights can affect the rubber, I can't confirm though.
Hi Rob, I have 14mm bands and a 6.6mm spear. What pretension weight should I have?
We prefer to match a 7mm spear with a 14mm rubber. Try about 5kg and see how it goes.
@@RobAllenSpearfishing same calculation? Half the barrel length +10cm?
I have a 80cm barrel, 14mm rubbers, 6.6mm spear and 120cm shaft
Rob, big fan here. I have your 1200 Tuna Railgun. It comes with two bands. How does the performance compare from the stock setup to switching to the single roller?
Hi Scott, the same set up (gun length and spear diameter will be better with a roller muzzle but not as big a difference when comparing a shorter gun. At about 1,3m there is not much advantage in power but there is much lower recoil. Some guys have problems with accuracy due to the recoil and a roller muzzle will help with this.
always awesome videos RA. is that 380% band stretch?
I think close.
@@RobAllenSpearfishing awesome
I’ll be fast asleep but I’ll watch first thing in the morning 👍🏻
Very interesting video. You mention the impact of temperature on the rubbers. I live in Denmark and often hunt in waters around 0-8 degrees. How do cold temperatures impact the rubbers? Since things often contract when getting colder, my intuition tells me to cut the rubbers a bit longer than normal - but what do you think?
The reverse. The warmer the water the better the rubber works. It is easy to cut the rubbers too short and over power a gun in warm water because the warmer the rubber the better the elastic return is. So, in colder water, the rubbers perform poorly, shorter is therefore better.
@@RobAllenSpearfishing I see, thanks.
Do you have a way to gauge how much shorter a rubber should be, if it's primarily used in cold water compared to warm water? Let's say 10c vs. 25c.
@@martincjoergensen Guys in the colder areas generally cut their rubbers a good 3 to 5cm shorter than our recommend, not an exact science 😁
Thanks again. I will experiment with that. Looking forward to the next video.
When are you going to do a video on converting a gun to a roller?
Hi Bruce, I will try do one when the factory fully opens. Pretty simple though, change the roller, drill out the handle screws and fit the rubber anchors. Cut and set the rubbers as explained in this video.
Perfect, thank you very much.👌🏼
@@RobAllenSpearfishing
Always sensible and perfect advice. Challenge is stainless anchors nowhere available.
Likewise Rob Allen master class spearguns. So SALVIMAR it is then.;-(((((
So if I understand it right. 90cm spreargun with 16mm bands you cut at 55cm of rubber length. What about 14mm rubber band? Should I cut it at 45cm?
No, keep it the same as the spear will be lighter.
Just bought the tuna roller 90 cm. Insaine power and precision - very nice. It is quite heavy in the water though. Rob, do you know if the gun will be close to neutral buoyant if I replace the aluminium tube with your carbon tube? Best regards from Denmark.
It will help.
@@RobAllenSpearfishing Do you know what the weight difference is between your 90 cm rail tube in aluminium and carbon? Then I can better guestimate the effect on buoyancy.
@@martincjoergensen I can give you the barrel differences. We have a standard aluminium (1,45mm wall) A 90cm barrel will weigh 385,1 grams. The same aluminium (1mm wall, same OD) is 306,9 grams. The carbon 90cm is 266,3 grams. The carbon dimensions are exactly the same as the 1,45mm aliminium barrel.
@@RobAllenSpearfishing Perfect, thanks alot Rob 👍
By half the rubber length plus 10 cm do you mean if its a 90 cm gun my 16 mm rubbers should be 50 cm? Does it hold the same for 14mm rubbers? Chris coats in his article tends to favor the 14mm for hand loadable shorter rollers.
Half of 90 is 45, plus 10 = 55cm. This is a good start. At 50cm it will work if the pre-load is 25kg or less. Yes, 14mm works to the same ratio but will give slightly less pre-load. Remember the 14mm rubbers will be best for 7mm spears.
can the same 1/2 barrel length +10cms be used for the 14mm bands
yes. You can also shorten it a little more than that if it works for you.
I have a Rob allen 750 Scorpia that i have converted into a roller gun. But the pre-tension is quite low. How will that affect performance ??
It will be under powered and probably shoot low.
Do you ship to Guam, if ordered from your website?
Sorry we do but only to our distributor there.
Fa’nu’i
570B West Marine Corps Drive
Anigua
96932
Guam
P: +16714826011
T: +16714776011
E:fanuiguam@gmail.com
@@roballen1578 Thank You sir! Appreciate the Reply! Love the videos and Gear! Will check him out asap! Guam 🇬🇺 Loves Rob Allen
Si yu'os Ma'ase (Thank you) in Chamorro
got a 120 GT carbon roller..... should i make my bands 70 cm each if im running a custom made 8.5 double flopper shaft?
Hi Pablo, I have tried an 8mm and did not like it, too heavy. I would think an 8,5mm would only make it worse.
hi rob , may i ask which model that carbon roller is ?
where could i find more info on that specific roller?
thanks.
roballen.co.za/product/speargun-tuna-roller-railgun/
RobAllenSpearfishing oh I though it was the ex carbon GT roller..
which I purchased second hand and was wandering if there is any difference than the limited edition GT roller?
@@talsilver1815 sorry, the GT is with a carbon barrel and the Tuna is an aluminum barrel.
Can I convert a rob allen tune 900 into a roller with the vecta handle? (NOT VECTA 2)
Yes you can.
What would be the recommended bluewater roller length
We feel a 1100 to a 1200 will be fine.
hello rob , im having problem on on my tuna railgun converted to roller, how long is the wishbone needed to be it seems like its still on the notch as it goes to the railing of the roller? its shooting downwards or could it be the recoil from the gun tipping the end of my spear?
There are many possibilities. What length gun is it? What shooting line are you using? What roller did you fit?
Rollers can be very tricky. The biggest problem is not tightening the shooting lines properly. If it is slack it can get sucked into the roller then get pulled out, jerking the shooting line and affecting the spear flight.
@@roballen1578 @Rob Allen my gun is 900 railgun and i bought rob allen roller kit and im using a 2mm dyneema. i have my bands at 55 cm . should i try go 1.8mm dyneema? my shootingline has tension with my bungee but ill try and make it a little more tighter
@@fidelrichardagpaoa3979 We only use 1,8mm Dyneema. Yes, try making it much tighter, especially the section from the spear line hole to the muzzle.
Great video, as always. I have a 140 tuna double 16mm rubbers. I'm considering to convert it to a double roller and to use twin 14mm roller rubers to hunt large pelagic fish like wahoo and sailfish. Do you think that this could improve the gun's range and accuracy? I'm thinking of a coatesman double roller head. Thank you
We have not done any testing on the double roller so I can't give advice, best would be to talk to Chris Coates.
Hello from Fiji
Hello.
my roller head still does not spin nice and freely, even after applying water and rinsing it. do you recommend taking it apart? or getting a part replaced?
There is a possibility that it has moved slightly on the shaft, causing side pressure.
I have the same problem, one not spinning freely. Ive spent a lot of money on ceramic skateboard bearing over the years so I've been super cautious in taking care of these bearings, washed in fresh water after each use. Ive bought two of these because I love my 100 roller conversion and I want to do a 120 in the future. Not sure if I should take it apart or take it back to the shop....??
Howzit Rob what are the recommended lengths for roller guns?
It all depends on your needs. Keep in mind, rollers are way more powerful and are double wrapped. A 1.1m will shoot as far as a 1,3m double rubber normal gun.
Hi..Rob Allen i want to buy a roller gun where can i purchase one?
Hi Steev, where are you in the world?
90 perfect to me
roller guns dont require mono? why?
We find the Dyneema less likely to tangle and cause inaccuracies.
i hope that dislike is a mistake
There is always one 🤣