Double 14mm bands vs single 16/16.5mm band

[671Spearo]

I have a question about the rubber bands on my Apnea competition 75cm speargun. It came with a single 16mm or 16.5mm band. I’ve been using this for a while now but I recently upgraded to two 14mm bands. I was wondering if this will make my shot more powerful, less powerful, or no difference. I’ve tested it out but it’s a bit hard for me to compare. While I was using the original 16/16.5mm rubber band, I would load it to the second notch. For my two 14mm bands I could only load one to the first notch and the other to the second notch. I would love to receive some advice regarding the difference in power/performance.

 

[Bill McIntyre]

I'm not familiar with that gun but I think that two 14mm bands will definitely have more power that a single 16mm band. And that extra power might increase recoil and cause shaft whip which would decrease accuracy. If the shaft came out oscillating that might actually decrease range.

But as I said, I don't know anything about that gun, so my comments are all just generalities. And another generality is that gun manufacturers may actually equip their guns with the proper bands in the first place. It's not always true, but we should be cautious of making changes. If you want more power and range, maybe you should buy a longer gun.

 

[Mr. X]

I agree with Bill. And I'm surprised you switched to 2x14mm before figuring out which was more powerful.

I guess it's not simple but I think we used to estimate it based on the rubber(s) cross-section area ( subtracting the usual big or small hole in the middle). But other factors come into play, such as length and stretch and rubber compound.

I too would expect 2x14mm to be more powerful. That said, I currently prefer a single 16mm bulk rubber. I've tried 20mm bulk, and bulk and screw-in 18mm bands ( I quite liked 18mm screw-in).

I also have a little used little 65cm speargun, 2x14mm. Which is easier to load than a thicker band but more time-consuming than a single band. The single 16mm bulk rubber seems like a very good compromise for the British waters I fish in (with a 75cm-90cm barrel length).

If visibility allows, as Bill already suggested, a longer speargun might be a better choice. It might well give better power, "balance" and "pointability" (I feel more accurate with a longer speargun when targeting fish that aren't close).

BTW I often take a 75cm and a 90cm Omer XXV speargun out with me, for the variable British visibility. Although I often think a single 82cm Omer XXV ( as recommended by wise and venerable former forum members: OMD, Spaghetti and Pavel) would do the same job more simply. [I think the 82cm model was not available to me at the time though :/ ].

If visibility is very good, it might be worth considering longer still e.g. 95cm, 100cm, 105cm or 110cm. But they will likely be harder to load, depending on bands used.

 

[Black_Reef_Co]

I have a question about the rubber bands on my Apnea competition 75cm speargun. It came with a single 16mm or 16.5mm band. I’ve been using this for a while now but I recently upgraded to two 14mm bands. I was wondering if this will make my shot more powerful, less powerful, or no difference. I’ve tested it out but it’s a bit hard for me to compare. While I was using the original 16/16.5mm rubber band, I would load it to the second notch. For my two 14mm bands I could only load one to the first notch and the other to the second notch. I would love to receive some advice regarding the difference in power/performance.

Retraction rate is parabolic from 300-400%, meaning 16mm at 350% will retract far quicker than 14mm at a lower stretch % even if it's multiple 14's with more overall force on the shaft. If you have no trouble loading it, I would go with a shorter 16mm band as opposed to two 14mm bands. But truly the best solution is to do a pool test and shoot it into a kick board

Which are you the most accurate with?

 

[guestthree]

I agree with Bill. And I'm surprised you switched to 2x14mm before figuring out which was more powerful.

I guess it's not simple but I think we used to estimate it based on the rubber(s) cross-section area ( subtracting the usual big or small hole in the middle). But other factors come into play, such as length and stretch and rubber compound.

I too would expect 2x14mm to be more powerful. That said, I currently prefer a single 16mm bulk rubber. I've tried 20mm bulk, and bulk and screw-in 18mm bands ( I quite liked 18mm screw-in).

I also have a little used little 65cm speargun, 2x14mm. Which is easier to load than a thicker band but more time-consuming than a single band. The single 16mm bulk rubber seems like a very good compromise for the British waters I fish in (with a 75cm-90cm barrel length).

If visibility allows, as Bill already suggested, a longer speargun might be a better choice. It might well give better power, "balance" and "pointability" (I feel more accurate with a longer speargun when targeting fish that aren't close).

BTW I often take a 75cm and a 90cm Omer XXV speargun out with me, for the variable British visibility. Although I often think a single 82cm Omer XXV ( as recommended by wise and venerable former forum members: OMD, Spaghetti and Pavel) would do the same job more simply. [I think the 82cm model was not available to me at the time though :/ ].

snake io​

If visibility is very good, it might be worth considering longer still e.g. 95cm, 100cm, 105cm or 110cm. But they will likely be harder to load, depending on bands used.

Detailed and complete analytical information. Each type has its own characteristics.

 

[popgun pete]

The only reason for two bands is split loading effort, if you can yank a single 16 mm band back then no problems. Multiple bands appeared on guns for that purpose. One gun that was designed by Big Jim Christiansen, the Scubapro 'Big Jim', had the mad idea to pull two bands back with one wishbone, the bands being somewhat skinny and looping separately either side of the muzzle on hooks. The gun crashed and burned once people tried it. I bought one.

 

[Mr. X]

I met a well known climber called Big Jim, several times, in Wales & Cornwall. Immortalised as the inspiration of the legendary Big Jim breakfast at the famous Pete's Eats climbers' cafe in Llanberis . And featured on some amazing DMM posters

Alas my Big Jim passed away too soon. His specialty was climbing hard routes without ropes . and often bare-chested (he had a fantastic physique, all muscle, no fat). Alas he fell soloing an easier route (for him!), in trainers! Actually I think he was down climbing it. It is long, multi -pitched too. So sad. A lovely, unique man - Big Jim Jewel.

Jimmy Jewell (climber) - Wikipedia https://en.m.wikipedia.org/wiki/Jimmy_Jewell_(climber)

UKC Forums - "Big Jim" Jewell

www.ukclimbing.com