Aqua Lung Dimension stability issues

[Bob DBF]

I can't think of anything else right now. Maybe your air is defective?

That was my first thought...

Drop the tank down on the wing and see what happens. It looks like the air is not passing through the top of the wing, it may be blocked by the tank.

I have a 40# wing! another brand, and have no issues, but I keep the body of the tank below the top section of the wing.

Of course if I'm seeing the video wrong, and all the above is a ll bulls**it and I have no idea what's going on.


Good luck


Bob

 

[JackD342]

That was my first thought...

Drop the tank down on the wing and see what happens. It looks like the air is not passing through the top of the wing, it may be blocked by the tank.

I have a 40# wing! another brand, and have no issues, but I keep the body of the tank below the top section of the wing.

Of course if I'm seeing the video wrong, and all the above is a ll bulls**it and I have no idea what's going on.


Good luck


Bob

That stimulated another thought - the Dimension, Axiom, and several other AQ BCDs have a different type of strap at the top of the BCD than what I think of as "typical." Their "valve retention strap" is NOT intended to hang the BCD on the tank, nor to cinch the valve tightly to the tank.
When your cylinder is standing upright, the top of the BCD should be standing a few inches out from the cylinder valve. That strap should be parallel to the ground, and only/barely snug enough to keep the BCD from falling forward while standing off from the valve. Do NOT tighten it up!! If you have that cranked down, that may be keeping air at the top from flowing freely between the two lobes. If I had my druthers, that strap would be #1 on my list of future changes to that BCD design. It is just not intuitive, and I really want to hang my BCD on the tank rather than support it while I close the buckle. Other than that, I really do like my Axiom. Same annoyance with that strap on my Rogue.

 

[.wilco.]

Just curious - where did you land on the Over The Shoulder measurement?

I can't think of anything else right now. Maybe your air is defective?

44" over the shoulder. Looking at the size chart again, it's mainly my weight that puts me in the M/L category. All other measurements could also be M.

 

[JackD342]

Too late now, but in that case (and admittedly I am writing sight unseen) I probably would have wanted to sell you a size M and added a belt extender if needed, and if it didn't make the belt too loose. They have a couple different types for the size "portly" crowd.

 

[.wilco.]

That stimulated another thought - the Dimension, Axiom, and several other AQ BCDs have a different type of strap at the top of the BCD than what I think of as "typical." Their "valve retention strap" is NOT intended to hang the BCD on the tank, nor to cinch the valve tightly to the tank.
When your cylinder is standing upright, the top of the BCD should be standing a few inches out from the cylinder valve. That strap should be parallel to the ground, and only/barely snug enough to keep the BCD from falling forward while standing off from the valve. Do NOT tighten it up!! If you have that cranked down, that may be keeping air at the top from flowing freely between the two lobes. If I had my druthers, that strap would be #1 on my list of future changes to that BCD design. It is just not intuitive, and I really want to hang my BCD on the tank rather than support it while I close the buckle. Other than that, I really do like my Axiom. Same annoyance with that strap on my Rogue.

I would love to measure it, but can't since the BCD is with Aqua Lung at the moment (or on it's way back, which apparently takes a couple of months). Didn't do the full measuring thing. Did measure if the tank was centered properly. Which it is.

Regarding the strap at the top; it's at the widest possible 'setting'. So not tight at all. I was thinking the same thing indeed. If the tank is pressing against the bladder, I don't know how to fix it.

 

[Heruhur]

I have the same BCD but with the i3 system, never had the problems you have.
It does tend to keep air in one side of the chamber, but a bit of a barrel roll is enough to redistribute the air evenly.
(or unevenly if necessary)
Something must be wrong with yours, even though they say it's not. Have you ever been able to try another one?
You could try cleaning it on the inside? Perhaps the bladder sticks together a bit, blocking passage of air?

@.wilco. P.S.: (dutch language) ik zie dat je uit nederland komt. wellicht kunnen we een keer een duik samen maken en het trimvest omwisselen om te proberen?

 

[.wilco.]

I have the same BCD but with the i3 system, never had the problems you have.
It does tend to keep air in one side of the chamber, but a bit of a barrel roll is enough to redistribute the air evenly.
(or unevenly if necessary)
Something must be wrong with yours, even though they say it's not. Have you ever been able to try another one?
You could try cleaning it on the inside? Perhaps the bladder sticks together a bit, blocking passage of air?

@.wilco. P.S.: (dutch language) ik zie dat je uit nederland komt. wellicht kunnen we een keer een duik samen maken en het trimvest omwisselen om te proberen?

Sorry for the late response! After a couple of months of back and forth, I've finally gotten a new BCD. Not because Aqualung acknowledged there's something wrong, but because it took a couple of months to send it back, and my dive shop, fortunately, agreed with me it was unacceptable to wait that long. I haven't been able to test it in the pool yet but will update this thread once I have.

@Heruhur [Dutch] Omwisselen is dus niet meer nodig, maar een keer een duik maken is altijd een leuk idee! I duik niet in droogpak, dus dat wordt dan wel ergens wat verder in het nieuwe jaar