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Circular band lenght!

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.

Memo

New Member
Sep 1, 2003
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Hi,
I'm a bit confused about calculating the circular band lenght to my gun.

Well I'm using a 110 cm eurogun and by definition I'm using 27.5cm long primary rubbers, but what will be the lenght of a circular band?
- is it 2x27.5 = 55cm?
- is it more than 55 cm?
- is it less than 55cm cause I'm pulling it only to the first notch?

thank you for your help!
 

SpearSlinger1

New Member
Dec 20, 2002
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I'm not sure I understand the question, but maybe this will help.

My Riffe Competitor #3XS has three 9/16"x24" bands. That means when I want to make a new band for it I cut a piece of rubber tubing 24 inches long and tie it into a new band.:)

I have tied longer bands for #1 (11 yr. old son) for easier loading, making up for some of the loss in power by using more bands. Also, I have heard of some folks who make shorter than stock bands for more power on a gun, but I, personally, shy away from this method, prefering to add power by adding bands or stepping up in diameter.

Does that help?:confused:
 

Shadowkiller

Digital Hunter
Jul 30, 2002
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Memo: I have 2 RobAllens, a 110 and a 130. I use a 70cm band for the 110 and a 80cm band for the 130. Both are 20mm bands. I use the shorter (relatively) band on the 130 beacause of its 7.5mm shaft. The 110 has a 7mm so I'm a bit more careful about overpowering it.
 

Memo

New Member
Sep 1, 2003
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In my 110cm cressi gun, manufacturer suggests 27.5cm eurobands (with plastic treads on each side), now I found Omer circular bands (also treaded on each side) and not sure about the lenght of it.

First I thought If originally there are two 27.5cm bands then circling them up to a 55cm single circle would be the appropriate one. Later I figured out the circled rubber has to turn around the muzzle and need some additional lenght but I'm not sure about this...

Any comments?
I think 65cm circle would be enough but not sure though.
slings7.jpg

Just have to find correct measurement for this..
 
Last edited:

Cingene

Will Dive for Food
Mar 4, 2003
400
30
0
Old rule of thumb is that the rubber must stretch three times it's length for a good power to stretch ratio.
 

Memo

New Member
Sep 1, 2003
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So how can I calculate the lenght? my 27.5 20mm euro rubbers can strech along with my gun fine. How about 60cm of circular?
 

Murat

Promethian
Jun 21, 2002
2,982
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Hey memo,

It depends what diameter will you use. If you will use power 18 it should be longer if you will be use energy 16mm it should be shorter. What is your gun model. I hear from many place that Cressi mechs are not realibale. Be carefull about that. Your idea about less than 55cm looks more correct to me but i don't know the correct answer.
 

Memo

New Member
Sep 1, 2003
1,237
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Well my gun model is Cressi-sub comanche 110cm. Well manufacturer offers 27.5cm long rubbers as a standart for 20mm rubber and I take that measurement as index. Well you're right about overpowering and junking the trigger mech. but we couldnt know the result without trying it ;)

I really wanna do my homework before I order the 18s from OMER. So if you have some more ideas please dont hesitate.

Regarding the less than 55cm. Now I think this will be the wors case scenario as the single circular rubber has to turn around the muzzle. This turn actually will make the circular band with 55cm work much shorter than desired.

But again this just my theory. :)
 

Cingene

Will Dive for Food
Mar 4, 2003
400
30
0
55 cm sounds right...but now, would the trigger be able to handle all that pressure?
 

Murat

Promethian
Jun 21, 2002
2,982
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Yeah i mixed my mind at that moment and said less than 55 but in fact i meant more than 55. Does your gun alluminium or carbon. Carbon model has rail and it should make huge different if you add second band.
 

Memo

New Member
Sep 1, 2003
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No rail at the moment but I could buy one in the near future. so we have a consensus at band lenght between 55-60 right???
 

shaneshac

FIN TRASHER
Oct 8, 2002
1,874
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Try the 60 first. After all you can always go for a bit more power if you find that works well. My Picasso 110 has 30cm long bands (20mm) and I have caught fish at over 4meter range.

Why would you need more power than 27.5cm G20 for 5 kilo max fish????
 

Memo

New Member
Sep 1, 2003
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Shane, you're right I dont need more power than G20s currently give but I know In my hunting area, there are some 20-40kg open water species :) I've seen them few times and they usually stay just at the edge of my range :(

Double 18s with a thicker spear is a project for my open water diving ideas :)
 

shaneshac

FIN TRASHER
Oct 8, 2002
1,874
178
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You will find that if they stay just on the edge of your range that you won't be able to catch them anyway.

Try to find a way of getting closer to the fish as opposed to using US military "More firepower is better!" techniques.
 

Memo

New Member
Sep 1, 2003
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rofl
hahahhaha your exactly descrbing my mood!!! You're right the key is to get closer, I have to find a way but a powerful gun will always be my project :D
 

Murat

Promethian
Jun 21, 2002
2,982
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Hey memo, did you see those 20-40 kg fishes offshore? I always swim from the shore up to few hundred meter but never saw that kind of fish.:hmm
 

Memo

New Member
Sep 1, 2003
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Those are not common but I've seen at a depth of 12m. while doing aspetto. Those are curious animals!!! So who knows with a powerfull gun and an organised blue water dive would bring them to the table?
 

Murat

Promethian
Jun 21, 2002
2,982
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If you don't have access to international dealer you can give a try to 130cm double band OMER Alluminium.
 

Murat

Promethian
Jun 21, 2002
2,982
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:hmm

Most of the euro speros online now. Wowww.. I don't feel alone anymore.

Hey Sahca why are you so silent?
 
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