STA Cumber Bands

[Xizang]

I've logged more than 10 dives ever since I switched to backplates and I believed I have fine tuned my rig except for one major thing. I cannot seem to position the tank so that my head would not hit the reg when tilting my head upward on a horizontal swimming position. I have adjusted the STA, back plate, webbings a lot of times already. I figured that the problem is the dual cumber bands on the STA which prevents me from sliding the BP further up the tank because the top cumberband will no longer grasp the tank. To solve the problem I thought of drilling another cumber band slot on the STA. When I went to my LDS, behold! they have an aluminum STA that only has one cumber band slot position at the center of the STA.

http://www.philtech.net/kag/tank_adapter.html

With the single cumberband STA I have more room to adjust tank position on the BP.

The single cumberband I think is common to many jackte style BCs and works quite well. I have not yet tested my rig with the new STA, but I was wondering.. is there is any functional reason why all (?) BP set ups have 2 cumber bands on the STA?

My LDS said that they came up with the single cumberband STA because they had problems selling their Diverite BCs (with the plastic STA) to some people who cannot seem to position the tank on the right spot on the STA.

 

[sprange]

I've seen many jacket users with their valves positioned almost halfway down their spine. You certainly won't hit your head, but I wouldn't want to try to reach the valve.

Sean P

 

[Xizang]

I don't plan to position it halfway down my spine probably just a an inch or 2 lower than its current position.

 

[sprange]

I don't plan to position it halfway down my spine probably just a an inch or 2 lower than its current position.

Certainly should be possible with most wings/backplates (at least the one's I've seen) without resorting to the STA you had mentioned. Is your first stage a yoke with a straight body, by chance? I could see how you could bang your neck into it in that case. That was the situation when my wife and I were in Bonaire and she was using a rental reg with one of my BP/Ws. That thing must have been about 5". Anyway good luck...I still doubt that you need that STA.

Regarding the function of two cam bands...while the STA will prevent the tank from wobbling, it's nice to have extra support if your tank is rather heavy (like my E8-130).

Sean P

 

[Lane Zimmer]

Sounds like your harness needs adjusting to me. From what your telling us, it seems as if the plate is too high on your shoulders. Put on the rig and look in a morror. See where the top of the plate is relative to your shoulders.

 

[Xizang]

Sounds like your harness needs adjusting to me. From what your telling us, it seems as if the plate is too high on your shoulders. Put on the rig and look in a morror. See where the top of the plate is relative to your shoulders.

the straps are already adjusted. I can touch the top part of the plate with the tip of my fingers when reaching back. I tried already tried sliding the plate further lower but it just makes the rig fit losely on the shoulders when in the horizontal position.

So, I guess the dual cumber band doesn't really have a big functional benefit at least if I just use a steel/aluminum 80s or 90s?

 

[kidspot]

you can also try putting the upper cam band through the plate slot instead of the sta - sometimes it is about 2 inches lower. Though once I got my harness adjusted properly I found I didn't have this problem. Plus my valve is really easy to reach now.

Aloha, Tim

 

[Xizang]

Got to test the single cumber band STA i bought already. works great! was finally able to adjust the tank to its proper height. No effect on tank stability even when walking a few steps on shore entries. If there is any positive side to it is that its easier and faster when changing tanks because only one single cumber band to shoot and adjust.

So I guess I can conclude that there really is no functional benefit on the dual cumber bands on most STAs. But that is only as far as my application of the equipment is concerned (open water diving in steel or aluminum 80s or 90s)