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OMER Trigger Mech

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.


Jun 21, 2002
Does anybody know how much pressure can OMER's Alluminium mech can hold SAFELY ????????

Does it release the spear as smooth under double 18 power band pressure?

Any experiance?
My friend's Omer Aluminum trigger housing cracked. Omer said it was electrolysis, and is now replacing the cast housing, with the T20 plastic one. Sucks, since the casts housing was the hype about the $400 gun. I think Omer owes more than just a trigger replacement. Sorry about the bad news. Just a word of warning before someone gets hurt.
Hiya Murat

Just curious, why would you want 2x18mm omer rubbers??? My 115cm C4 had 18mm omer bands on, and they were potent. Can't really see the need for two 18mm's unless you're shooting large pelagics.

The omer 18mm's are very wicked!!! Just as much power as my 20mm's (well in my opinion of course!!:D )

Very true... if you are looking for a lot of power... take 2x16mm, that is a lot! or you could take a very short 20mm (which would be hard to load!)
i am thinking to use this trigger mech in 120-130 wood speargun. But the thing is that sometimes the shaft speed,range may not be fast enough for some med sea fishes with one band. Thats why i am asking.

I am thinking to buy AJ/Dentex gun for this summer.
hey, i own a omer carbon alum. 110

i have been using two omer 18mm Power rubbers since last summer... no problems. Also i have had the gun for two years now... The gun seems durable to me. Dont know how the trigger frame could have cracked for that one dude... could have been a bad apple :( wierd cuz mine is built real solid...

I also own a beuchat mundial.

My new gun will be the rabitech Apex 130 Carbon :D i might go and take a look at the gun tomorrow at the sumora dealer.

You won't be disappointed by the Rabitech Apex!!!!!!

On Rubber

Murat: I would be very surprised if there is any difference in the performance of a trigger mechanism's release cycle as a result of new rubbers. These are usually quite robust, and the differential in the force applied to the trigger mechanism as a result of rubber changes would be relatively small.

I have been a lurking member of this forum for some time now, and often see divers saying one rubber is more "powerful" than another, and they only use this rubber or that rubber. And this one is more powerful because its red, and that one more powerful because its green, black … insert a colour.

In terms of comparing the power of one set of rubbers to another it is not technically possible to do this without ensuring that the rubbers are the identical length and are being stressed under identical conditions. Only then, and under quite precise circumstances, will it be scentifically verifiable that one rubber is more "powerful" than another.

Rubber is measured by the pulling power, usually measured in pounds, that it can exert at a specific length, usually measured in inches. So it is very possible to have 12 inch 20mm rubber bands elongated to 60 inches provide less "power" in a given setup, than an 8 inch 16mm rubber bands elongated to those same 60 inches. The reason for this is that the 16mm rubber has been elongated further as a percentage or its resting length. So power per se, is all a question of unique circumstance, and in truth, my experience and its all up to individual preference in the end, is that providing you are using rubber from a reasonably credible supplier the differences in performance are really quite negligable.

A good place to checkout a design for setting up an environment for testing rubber can be seen here:


You can see how he has the scale there to provide the poundage readings, and has marked off the various lengths for measurement. In the past we have used a fence strainer (available in most hardware stores I would imagine) to provide the pull. The scales on the other hand are expensive and quite hard to come buy.

You can read more about rubber here:


But the real rubber guru, or so I am told, is a chap called Moari (Sp??), somewhere on his site is a substantial chart of all sorts of rubbers that he has tested, and their various readings and power ratings. Its quite impressive. I don’t have the url to hand, but I am sure it is out there, and another member of this community knows how to locate it.
hi Russell,

thanks for your effort.

but you missread my question, i am not talking about changing to different band. I am thinking about using that mech (omer alluminium) on another gun which uses double set of 18mm bands.
The truth for speargun BAND POWER

Hi Murat Russel & friends on the DB forum,

I just returned from a great trip spearfishing in Central America and testing out new equipment under some awesome conditions. More on that later when I have a minute but I wanted to address a couple points in your post

We carried out a spear band test using the same testing facility Beretta firearms uses to carry out their firearm tests in 2000' and I have not released the data worrying about some of the possible repurcussions for a few years. Until now!

In short, you will see that under controlled circumstances and variables accounted for (temperature, dry firing a speargun, using the same size speargun, same size shaft and same size bands for the entire test) the data learned working on achieving the compound used for the Power 18mm bands is not so plain cut and dry as we might sometimes think. Surely, not all bands are the same. Here are comparisons with all the major brand manufacturers. I'll let you guys have fun and figure out how to interpret the data saying only one thing.

66Kg, the pull required on the 18mm bands, is 145lbs. The sentence underneath the chart with the * before it says:
The loading effort *(sforzo di caricamento) limit for even the most avid speargun user is widely held at 70Kg(154lbs). After this number, it becomes EXTREMELY hard to load a speargun, I for instance do not choose to load even our newer 20mm bands which are probably 5Kg's or so harder to pull than the Power 18mm's.


sorry on the last post guys, forgot to add the attachment


  • rubber-test2000\'.pdf
    89.8 KB · Views: 259
thats right, i used 20mm old omer black enery or may be top energy bands on my old MB 30/86 gun, black master also uses same bands. Even the gun was 86cm but bands were hard to load. But new 18mm bands on my 100cm gun can be load almost "efortless" i put the butt of the gun to my stomach and can load it to the second notch at first pull (hovewer keeping the bands on the second notch weakens the bands more faster than it supposed to be.)
Re: On Rubber and handle


Here is the bands-rubber test link...



If I would have to buy a new handle for a wood double band speargun and I had the $$$ I would go for the Master America handle. If I didn't had the $$$ I would go for the normal T20 or the Mundial handle. Since you a have a T20 why don't you use that handle for the wood gun and buy a cheaper Excalibur for the small gun...


Mark ... thanks for your post.

Please can you post or send me the data, I would be very intrigued by your findings.

Lastly fellas, looking back on Murat's original post and query you should know that the Excalibur or any OMER parts or spearguns are not covered under warranty when more than the reccomended stock power is used :waterwork Only the models which specifically come set up with two bands or are explicitly reccomended for the use of two bands like the T-20 and Master America guns would be covered under failure if it was proven that the gun was not abused or modified into overkill.

If there's one piece of advice I can give its this- trust the way the gun is setup stock from factory, 99% of the time it will be more accurate, better balanced and perform better stock.

Ciao, Mark
ps- the one who has unoficially loaded the t-20 to 450lbs without any problems or trigger sensitivity issue.
well here excalibur and t20 cost same, and i use 75cm gun extensively. I think if i decide to buy the wood gun in my mind i will use new t20 orthopedic handle. Actually main problem that keeps me undecided is that, i will buy new wood gun at this summer for sure size between 110-120 may be double 18mm band or probably it will be single, with 6.5 mm shaft. It will have full length rail. But i can't decide about open muzzle or closed muzzle. The infos that i gather up to date is says;

-open muzzle better hydrodynamic and easier aim (hovewer this i am not interested with this much)

-bulk rubber pull the band more that screw in bands due to lack of closed head but since the bands are not parallel to the shaft, shaft can go bit high but i will have rail on the barell, i don't know if this will prevent it. Parallel band transmit energy to the shaft more efficiently and it will shoot accurate but with less band strech.

If my ideas about shooting high with bulk rubber is not correct i will go for open muzzle one.
Hey Mark,

That test shows that the Power 18 are very efficient and give back a lot of what is put into the loading effort.

Has the test been repeated using heavier shaft see if the 20mm bands can move the heavier bands quicker than the 18mm bands.

There is so fast a band can contract. After about 30m/s the force required to get an extra m/s is too great due to water resistance.

Although I am quite sure a 20mm band e.g Beuchat, will far outperform the 18mm bands for moving a greater load. This will probably still hit 30m/s whereas the thinner bandswould probably not.

I have not tested this theory so am not 100% sure.

By the way I spoke to Marco (Omer Owner) at Eudi show. Said we had given you some grief about the Omer products. We had a great laugh. ;)

Take Care