Bungee types - again ;)

[Razorista]

Since someone asked to make this a new thread here it is

In my opinion all currently preferred bungee systems work identically with only cosmetic details separating them.
Loops, floating loops, two separate bungees or a single bungee all work best with matching valves and ingenious twists of the bungee around those.
They also work with any non matching valve 'somehow'.

Depending on where the bungee is attached they also influence the best position for the tank valve.
With loops attached behind the shoulders full or heavy tanks hang more comfortable if moved backward towards the legs compared to single bungee or separate bungee, both of which work best with the valve/first-stage more or less touching the shoulder D-ring position.
That difference is mostly cosmetic however. Minimal changes in hip D-ring and lower boltsnap positions are required to replace one bungee system with the other.

Some older systems like the ring bungee system work differently, but except for the ring bungee system most of those are used only by a very small and rapidly reducing number of divers.

 

[tbone1004]

what do you want to know?

single bungee is stupid, you loose tension on the other side if you remove one tank, and if the bungee breaks, then both sides are gone
two separate bungees are better because they are independent, but they still force the valves to be up towards the front D-rings, and that causes the valves to hang too low. This is the downfall to the way the ring bungee system is explained. Lamar puts the extra quick links for length adjustment on the plate side, which leaves the necks too low. Don't say older, because ring bungees are actually the newest of the bungee styles

Loops are the best, they cause rotation around the main axis of the tank which rolls them up and into the diver to limit movement when you roll to a side.

 

[DevonDiver]

I educate two bungee methods as standard:

1. Floating Loop. In my opinion, the best solution provided you have L/R-handed valves with stems. i.e. you own/dive, or can source when travelling, dedicated sidemount cylinders.

2. Separate Bungees w/bolt-snaps. In my opinion, the best solution when you primarily dive in locations where you won't get dedicated sidemount cylinders. This is the 'universal' method - best for travelling divers.

 

[Razorista]

what do you want to know?

Just want to collect some viewpoints and probably clear up some of the most obvious misunderstandings.
So do not take what comes next the wrong way:

single bungee is stupid,

I like stupid. It is the last S in KISS

you loose tension on the other side if you remove one tank,

That is intentional!
That way the loops under the armpits can be shorter than with separate bungees while still being able to slip them over the valves.
You have a longer Bungee to flex and pull.
You also only pull against one bungee string, while the other half of the loop is already attached to the D-ring - only half the force is needed to pull it over the valve, but people always use that extra flexibility to make the bungee even shorter.

and if the bungee breaks, then both sides are gone

No, the bungee will not even lose tension much. It is squeezed in much to tightly by the webbing loop it runs through on your back.
You will have to actively pull it through that loop to replace it.
That's the main advantage of it: It can be replaced on any failure.

Even If the bungee would not hold the second tank, the hoses will until the replacement bungee is ready.

This is a theoretical problem with no basis in real diving.

two separate bungees are better because they are independent,

Why? What makes independent 'better'?
When one fails it cannot be replaced easily. You either have to clip a 'hard attachment' to the shoulder d-ring, or use a single bungee as replacement with the second separate bungee in the way.

On a single bungee if one side fails you can pull out everything at the intact and always accessible side, replace, good as new.
Achieving the same tidy setup after a failure with most other systems requires leaving the water.

but they still force the valves to be up towards the front D-rings,

Intendet!
That' where 'we' want them. 'We' being people like HP, Steve B., but also the 'early' Steve Martin and incidentally: me.

and that causes the valves to hang too low.

lower, yes, but define 'too low' please. Who decided the 'too' part?

This is the downfall to the way the ring bungee system is explained.

It's (the ring-bungees) downfall is its complexity.
Most people make critical mistakes in the setup without realizing.

Don't say older, because ring bungees are actually the newest of the bungee styles

true

Loops are the best,

That's an opinion shared by many, not me though.

they cause rotation around the main axis of the tank which rolls them up and into the diver to limit movement when you roll to a side.

Identical to a single bungee setup.

I educate two bungee methods as standard:

I help with lots of different styles at the moment:
single with boltsnap or attached directly to webbing or D-ring, loop (hard attachment), floating loop, separate with boltsnap or hard attachment, ring bungee and two or three individual styles I have never seen on anyone else but one user who thinks he came up with the idea himself.

1. Floating Loop. In my opinion, the best solution provided you have L/R-handed valves with stems. i.e. you own/dive, or can source when travelling, dedicated sidemount cylinders.

That's not the only disadvantage, but one of the most significant: bad for traveling or rental tanks in general.

2. Separate Bungees w/bolt-snaps. In my opinion, the best solution when you primarily dive in locations where you won't get dedicated sidemount cylinders. This is the 'universal' method - best for travelling divers.

I see only disadvantages compared to a single bungee solution.
Works the same, isn't as foolproof and the bungee loops they form are either longer or less flexible.

 

[Bennno]

Just want to collect some viewpoints and probably clear up some of the most obvious misunderstandings.

I can't wait until you explain to Andy and Tom what they have misunderstood.

 

[Razorista]

I can't wait until you explain to Andy and Tom what they have misunderstood.

?? already did so

 

[Razorista]

Here you have the way the loop is manipulated with a single bungee:
I so not see any difference to the way a floating loop or two separate bungees are used.

 

[DevonDiver]

I've tried all the bungee methods extensively, with the exception of ring bungees. I say 'extensively' to indicate well beyond three-figure dive experience with each type. Ring bungees were very unsavory with aluminium cylinders... So I only bothered with them for a few dozen dives before writing the method off for warm water diving.

Continuous (single) bungee just isn't as refined as the sliding loop or separate bungees. I dived it for a few hundred dives... and.... Meeehhh.

Its good as a quick fix if you arrive at a dive center that doesn't have stemmed tanks to run your sliding loop bungees. I carry one for that purpose, as I travel remotely.

I'm fully conversant with Steve and HP's advocacy for the continuous bungee and why they use it. I just don't feel it offers the performance for a wide spectrum of divers that sliding loop does. Also, for me, a bungee failure and dropped tanks is far too much of a hazardous risk in cramped wreck environments.. where dropped stuff can get damaged, jammed and entrapped very easily.

As for continuous versus separate. I lose a grand total of 3" length and associated flexibility. No biggee... I've trialed 14+ types of bungee, so I'm fully in control of exactly how much flex and strength I desire for my tanks. I've used 14mm,12mm, 8mm, 6mm, 4mm, doubled 4mm, doubled 3mm... you name it... flex and strength isn't why you choose a bungee method... It's why you choose a bungee material.

Bungee method is chosen for cylinder control, security and to suit your diving needs.

 

[Razorista]

...I say 'extensively' to indicate well beyond three-figure dive experience with each type.

I cant compare with that. I gave each method two or three dives, not more, repeated that a few times though.

Ring bungees were very unsavory with aluminium cylinders.

So I only bothered with them for a few dozen dives before writing the method off for warm water diving.
Failed me on the first, second and third tryout dive. Did not give it much of a chance after that.

Continuous (single) bungee just isn't as refined as the sliding loop or separate bungees.

Some people like the quick and dirty way to do things.

Also, for me, a bungee failure and dropped tanks is far too much of a hazardous risk in cramped wreck environments.. where dropped stuff can get damaged, jammed and entrapped very easily.

That one I do not understand.
Single bungee isn't any more likely to 'drop tanks'.
It can be repaired in contrast to all other systems, so by your own definition you should favor it.

 

[tbone1004]

you have to have more than a handful of dives on a system because there is a lot of factors that have to be changed between the two to optimize the setup so you are diving it the way it is supposed to. Once it is dialed in, you have to allow Thorndikes Law of Intensity to take over so you learn how and why people choose their system and the pros and cons of each. Only have you have done that can you decide that it is not the right system for the diving that you are doing.