Sidemount BC

[tbone1004]

14l is 30lbs, 16 is 35. Using 2.2lbs/liter. Easiest way for this is literally just to put it on and weigh yourself+the rig and note the scale number, then with the rig on, fill it until it is full of water and weigh again. The delta is the weight of water in there, which is the amount of lift the rig has in fresh water.

 

[decompression]

14l is 30lbs, 16 is 35. Using 2.2lbs/liter. Easiest way for this is literally just to put it on and weigh yourself+the rig and note the scale number, then with the rig on, fill it until it is full of water and weigh again. The delta is the weight of water in there, which is the amount of lift the rig has in fresh water.

Thanks Tom, you just beat me to it.

 

[Bennno]

Wow, I really didn't expect that it could fit that much. Thanks for doing that. 16 liters is very close to 37 lbs. It's roughly 1 kg per liter.

 

[Bennno]

I was way off. I would have guessed 12l maybe 14l, tops. Lucky me you don't live close to me, otherwise I would have bet you a 24 of Moosehead...

 

[Razorista]

The problem with those wings is not the overall size.
The are either bungeed into shape or constructed with other constriction methods.

Constricting the wing, however, will increase the pressure on the dump valve with a full wing.
Trying to carry a heavy load with a full wing especially at depth can cause the dump-valve to overreact and dump overpressure early, severely reducing the maximum wing capacity.
You loose at least the last 2-3 liters / 4-6 lbs that way, if you want to be sure with a small margin of error on top.

 

[DevonDiver]

A sliver of 3-4mm bungee is pi$$ing-in-the-wind compared to the force exerted by gas pressure on expansion etc.

So much nonsense spouted on the forum sometimes.

 

[Razorista]

A sliver of 3-4mm bungee is pi$$ing-in-the-wind compared to the force exerted by gas pressure on expansion etc.

So much nonsense spouted on the forum sometimes.

You should know better @DevonDiver.
Didn't you construct your own often enough?

The dump valve is the problem. It is meant to dump on the slightest overpressure.
Bungees create pressure, everythng above 'zero' is too much in theory.
The pressure adds up, three short 3mm produce roughly the same force as one 9mm.

In practice it is even more difficult since overpressure valve maintenance is often neglected.
New ones often hold too much pressure, but they age quickly.
Many open early or aren't absolutely closed from the beginning, others get stuck open when pulling when the wing is too full.

It is a very old known fact and one of several reasons why bungeed wings are frowned upon by many.

 

[DevonDiver]

I do know better Razorista. I've dived bungee wings, backmount and sidemount, cold-water and tropical, for more than 15 years.... totaling many thousands of dives.

Which is exactly why I posted what I posted.

I think you are confusing your internet research. The old 'DIR' issue with bungeed wings was relevant to bladder failures and not being able to 'trap a bubble' as effectively. There has been no issue with OPVs... and, as such, it is not a "very old known fact". Indeed, it is made-up gibberish and nonsense, regurgitated by people who haven't bothered to check the reality and/or have no direct personal experience of the issues involved.

 

[Bennno]

The razor also has a bungee wing.

 

[Razorista]

The razor also has a bungee wing.

You are right, it does, but the construction is different and negates most disadvantages or uses them as an advantage instead.
That leaves you with the 'dreaded beach ball effect', though.