How Do These Bungees Secure The Tank?

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Question: why is it better to have tanks more towards the front, with valves in the armpits (as opposed to further back like I have them right now), does that have something to do with the tanks being closer to center of gravity and staying better in trim as the gas is drained and they become more positive? Or is that not a reason and/or there is some other reason?
 
Question: why is it better to have tanks more towards the front, with valves in the armpits (as opposed to further back like I have them right now), does that have something to do with the tanks being closer to center of gravity and staying better in trim as the gas is drained and they become more positive? Or is that not a reason and/or there is some other reason?

There's a few reasons, some are diver-specific.

Firstly, not every diver is tall enough to permit the cylinders to positioned lower. If the cylinder band is set-up at the appropriate height, this can mean the band was above the fulcrum of the tank... tail rise would be unavoidable.

Even if you were tall enough to permit a 'low slung' cylinder - you're messing with the hose routing. In short, you're adding inches to the hose length requirement... and some hoses (like LPI) won't be precisely where you need them.

There is also the issue of lowering bouyancy on the center-of-gravity. This is primarily an issue when diving aluminum tanks. The lower the tanks, the more pronounced the lower-torso lift will be when tanks get increasingly floaty.
 
Thanks!! I guess I will have to experiment with both and see what feels more comfortable. I am 6 feet tall and my Worthington HP100s are pretty heavy at any pressure, but I guess that may change with the Faber HP100s, I am just about to find out... I did notice slightly uncomfortable changes in my trim when I don my 2xAL40s on and off in the water, not sure that has something to do with tank position being more forward or backward or just the overall weight and bulk.
 
There's a few reasons, some are diver-specific.

Firstly, not every diver is tall enough to permit the cylinders to positioned lower. If the cylinder band is set-up at the appropriate height, this can mean the band was above the fulcrum of the tank... tail rise would be unavoidable.

And THIS is my worry. I'm 5'8" (173 cm) and I've had to deal with "floaty-tail" aluminum-80 tanks (12-liter tanks outside the PSI-Zone) from the start of my side-mount experience.

Even if you were tall enough to permit a 'low slung' cylinder - you're messing with the hose routing. In short, you're adding inches to the hose length requirement... and some hoses (like LPI) won't be precisely where you need them.

As Popeye said, "I yam what I yam." If I have to change or re-route my hoses to match a new configuration ... that's just the way it is,

There is also the issue of lowering bouyancy on the center-of-gravity. This is primarily an issue when diving aluminum tanks. The lower the tanks, the more pronounced the lower-torso lift will be when tanks get increasingly floaty.[/QUOTE]
I'm glad I'll be able to "get wet" with the new BCD tomorrow morning. Hopefully I can get it weighted right for fresh (pool) water ... and maybe, a September/October trip down the Florida coast will be enough to get it rigged for salt water.
 
@BeijaFlor did you push the button on the Katana? If so, let me know how the loop bungees work for you. That was my main setup problem with mine (just arrived). Anyway, I took the installed bungees out and ran a slightly longer and less stiff bungee loops.
 
Yes, I did, and I'm really pleased with it!

I have this local Hollis dealer who has a full 25-yard indoor pool, who let me take it for a demo dive. Took me about a half-hour to figure it out, and I spent a little more than 1/2 hour in the water - then I went back into the shop and said, "CHAARRRRGE-IT!" Then I went back to the pool for some more adjusting, tweaking and fiddling - and another half-hour blowing bubbles, turning and pivoting, swinging the tanks butt-forward and going through their diamond rings, clipping them off and then on again, and doing all the "stupid sidemount tricks" that came to mind. I did that second pool-session with 6 lbs of lead and 1000 PSI in my tanks, neutrally buoyant with the wing utterly empty ... proof enough!

The loop bungees were a major problem for me, too -- I ended up just looping the valves with the thin guide-line bungee that connects the loop to the shoulder-strap. Good enough for a demo, I figured, and I had bolt clips choker-looped on the tank valves for the weight-bearing connection. I'll mount longer loops before I take the rig on my next vacation.

My tank-rigging is simpler, too ... I had fixed up stage straps, and choker-straps to hold the bolt clips close to the tanks, to mount my tanks on the ring bungees. Don't need that any more, just one bolt-snap on a choker at the top of the tank and another on the cam-band 8 inches from the tank base.

I'm going to enjoy this rig. Maybe I ought to buy a couple of tanks and a 5-mil wetsuit so I can enjoy it near home.
 
https://www.shearwater.com/products/swift/

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