Looking for opinions - Doubles Wing for AL80 Twin Set

[Tyler Q Hemmerich]

Hey All,

I'm a relatively new tec diver and looking to learn from others and avoid expensive purchases of the wrong, for me, kit. I'm building a pretty standard twin set using 7.25" Luxfor AL80s and DGX valves and bands. A wing is the next purchase. To date all my twin set dives are in warm salt water using AL80s with a SS BP and my instructor's XDeep wing. At the beginning of any dive, a 2 lbs weight strapped to the bottom of one of the tanks gets me trimmed up fairly well..... but I become progressively more head-heavy / butt-light as a dive progresses. Researching donut-style wings, it seems some have equal-ish volume from top to bottom (X Deep, OMS), others appear to put more air volume down low (DGX Gears D1), and some seem to have less volume down low (Apex WTX-D / Dive Rite Classic).

Can anyone comment on the head-to-butt buoyancy characteristics of the more common double wing options? And, comment on wing(s) that might help me negate this progressive head-heavy / butt-light trim problem?

Any advice will be most welcome.

 

[Marie13]

I loved the Dive Rite Classic XT when I had my doubles. But I can't comment on buoyancy characteristics. It handled my short steels just fine (they're about 4" shorter than an AL80).

 

[wKkaY]

It's a fairly common problem, and can also affect steels like the faber 12.

I have the xdeep hydros 40lb. One thing about it compared to halcyon is that the wing has 2 sets of mounting holes, so you can adjust it higher or lower depending what you need.

I'm not sure how much difference the wing shape makes to balance when the tanks are sucked down, as they are also less inflated. I've squeezed the top of my wing and didn't seem to feel much in it.

I've accepted that the best I can do is to weigh myself to hold a zero degree trim with full tanks, and progressively go off horizontal as they empty.

 

[divezonescuba]

Are you using the XDeep Hydros or the nx project wing?

The shape of the top of the wing has a definite effect on the trim. I use a Diverite rec 45 lb wing for al80s. I bought a set of LP85s thinking that the buoyancy characteristics would be similar. I was wrong and had to go up to the diverite classic 60 lb wing. It has a lot more buoyancy on the top being square In comparison to the rounded rec 45 and found myself too foot heavy with the LP85s. I was able to mitigate this by repositioning the wing and plate on the studs.

The nx project is specifically designed to have more lift on the bottom. So if that is what you Are using, I am not surprised. There is an xDeep promotional photo with a guy wearing weights on his tanks as well.

however, in general, I think that you have to start the dive In slightly foot heavy trim to compensate for the change in buoyant force position over the dive.

 

[RyanT]

I have a couple of wings. You are right about the DGX wing. It's a decent value for a wing, but it does tend to have less flotation near the top. That will definitely mess with your trim in AL tanks. The SP wing I've got distributes the air more evenly top top bottom.

 

[Kevin Floyd]

My OMS bondage wing of death has two sets of holes so it was easy to adjust. On my steel LP 95 set I put the plate on the second hole and the wing on the top hole. I maintain perfect trim throughout the dive.

 

[azstinger11]

I have a Hollis LX45 wing that I like in AL 80 doubles. Actually has 3 mounting hole sets.

 

[halocline]

Hey All,

I'm a relatively new tec diver and looking to learn from others and avoid expensive purchases of the wrong, for me, kit. I'm building a pretty standard twin set using 7.25" Luxfor AL80s and DGX valves and bands. A wing is the next purchase. To date all my twin set dives are in warm salt water using AL80s with a SS BP and my instructor's XDeep wing. At the beginning of any dive, a 2 lbs weight strapped to the bottom of one of the tanks gets me trimmed up fairly well..... but I become progressively more head-heavy / butt-light as a dive progresses..

I don't think the wing shape has nearly the effect on trim that other factors will, and I wouldn't worry about it too much. I would buy a fairly small wing; you should not need a huge amount of lift with AL80 doubles, even with a thick wetsuit. Unless the wing is really filled with air, the bubble will rise to the highest point. I use a dive rite rec wing and it is PLENTY big enough. I would prefer a smaller wing. Mine is one of the older ones; they're bigger than the new ones.

In terms of fixing your trim, I would try an AL plate instead of the steel plate, try moving the tanks a bit lower on your back, (keep the bands high on the tanks, and maybe move the plate down one set of holes) and experiment with heavier fins if you have not done so. Fins have a really big effect on trim IME.

I would also work to get your weight requirements as low as possible. You might be surprised. I need about 8 lbs with a single AL80 and almost nothing with doubles. It's counter intuitive because we know that the positive buoyancy of the tanks is doubled when you're carrying two of them. But the bands and manifold add a lot of ballast, more than a steel plate, and it's all up there on your back.

 

[stretchthepenn]

...experiment with heavier fins if you have not done so. Fins have a really big effect on trim IME.

I concur with the fins suggestion. When I dive SM, I use a pair of OMS Slipstream (roughly neutral buoyancy) fins, but when I dive a BM twinset, I use Hollis F1s (very negative). With the neutral fins in BM doubles, I flop head-down in a big ol' hurry.

 

[rudytuhbooty]

I put together a set of double 80s last year and they pair very nicely with my dive rite rec wing. I need a 4 lb tail wait to keep from going feet up when the tanks near empty but it also is the perfect weight to have an empty wing at the hang bar on my saltwater dives with no additional lead in a 7 mm wetsuit. All in all it is probably the easiest setup to dive that I can think of. They balance well and are super easy to swim up if I lost my wing.