djcheburashka
Contributor
Tbone: a lot of people shed weight when the rig becomes more balanced. Because when it was unbalanced they were using the weight and lots of hard work to get through the dive.
First stage, face up or down? Also, SPG sticking up or under the arm?
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victorzamora
Contributor
Only if you're diving trim weights would scrunching the wing help you shed weight. Unbalanced, I think, is a mistaken word. An "unbalanced rig" is not one that gives poor trim, but one of undesirable buoyancy characteristics.
djcheburashka
Contributor
Yes, I agree, but a rig can be unbalanced in more than once axis.
I'm not sure the connection you mean between wing-scrunching and trim weights. In my view, bungee-scrunching a wing and attaching weights to a tank are both exceptionally poor ideas.
I briefly dove with a bungee-scrunch wing early on. It really did, as the warning say, trap air and make it hard to dump. I really don't get the point, except to hold the wing in some kind of position, which implies the wing is just poorly designed.
Which is also why unbungeeing the wing can let you take off weight
I'm not sure the connection you mean between wing-scrunching and trim weights. In my view, bungee-scrunching a wing and attaching weights to a tank are both exceptionally poor ideas.
I briefly dove with a bungee-scrunch wing early on. It really did, as the warning say, trap air and make it hard to dump. I really don't get the point, except to hold the wing in some kind of position, which implies the wing is just poorly designed.
Which is also why unbungeeing the wing can let you take off weight
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you clearly don't understand sidemount or your wouldn't have made those comments because this situation has absolutely nothing to do with backmount.
The SMS100 wing is too large at the top of the wing contributing to the diver experiencing too much lift at his shoulders. The modification rolls the top of the wing to the inside to keep the air in the hips where sidemount divers need help. Similar to the DiveRite Rec wing where the bungee just pulls the edges in and can't trap air because it doesn't create pockets. Has nothing to do with the OMS bungeed wings and it certainly doesn't trap air anywhere. The modification is there because the wing is poorly designed, the SMS75 mostly fixes it.
Weights to a tank on an AL80 in sidemount help to keep the tank butt from floating too much, the weight is there solely to counteract the buoyancy of the tank, so it is really no different than having a steel tank with neutral or slightly negative buoyancy characteristics.
The SMS100 wing is too large at the top of the wing contributing to the diver experiencing too much lift at his shoulders. The modification rolls the top of the wing to the inside to keep the air in the hips where sidemount divers need help. Similar to the DiveRite Rec wing where the bungee just pulls the edges in and can't trap air because it doesn't create pockets. Has nothing to do with the OMS bungeed wings and it certainly doesn't trap air anywhere. The modification is there because the wing is poorly designed, the SMS75 mostly fixes it.
Weights to a tank on an AL80 in sidemount help to keep the tank butt from floating too much, the weight is there solely to counteract the buoyancy of the tank, so it is really no different than having a steel tank with neutral or slightly negative buoyancy characteristics.
djcheburashka
Contributor
I find your comment deeply amusing
The sms100 wing design problem is just a design problem. If you think about the physics just a wee little bit you'll see that the bungees physically cannot be performing the task you think they perform. They will however trap air
Oh-Hollis also, not just OMS, made bungees backmount wings until they were rejected by the market. Just FYI.
As for weights on tanks... Yes years ago people who have rigs with "door handle" butt-plates often put weights on al80s. This was a bad thing. The solution was that people moved away from using door-handle butt-plates, at least when diving with aluminum tanks. This was one of the innovations of the razor- generation of rigs.
Today the debate is whether to use door handles with heavy steels or dump them entirely. I don't think many people would defend the weight-on-tank theory anymore.
(Honestly is pretty indefensible; if you want a tank with those buoyancy characteristics just use hp80s or hp100s.)
The sms100 wing design problem is just a design problem. If you think about the physics just a wee little bit you'll see that the bungees physically cannot be performing the task you think they perform. They will however trap air
Oh-Hollis also, not just OMS, made bungees backmount wings until they were rejected by the market. Just FYI.
As for weights on tanks... Yes years ago people who have rigs with "door handle" butt-plates often put weights on al80s. This was a bad thing. The solution was that people moved away from using door-handle butt-plates, at least when diving with aluminum tanks. This was one of the innovations of the razor- generation of rigs.
Today the debate is whether to use door handles with heavy steels or dump them entirely. I don't think many people would defend the weight-on-tank theory anymore.
(Honestly is pretty indefensible; if you want a tank with those buoyancy characteristics just use hp80s or hp100s.)
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The SMS100 is a design problem, we all know it, but Nick Hollis in his infinite wisdom won't change it. Lamar won't change the Nomad wing design either despite many requests to both parties to make the top of the wing simply a crossover passage for air, similar to the crossover on the CCR wings. Neither party has done this, though Lamar at least put a port on each side of the bottom for inflator swaps, so we have to come up with a solution. That solution on the SMS100 is rolling to the top of the wing over. Rolling the top of the wing does not allow air pockets to be created unless you are upside-down because the top of the wing is still smooth. The other point is that because this passage is now smaller, the air is less likely to get trapped between the shoulder straps, which is a very common problem with non-modified wings. My solution was to use an XL-Tall transpac on my nomad which pushes the whole wing down 2 inches so the wing is squished between the transpac and my back and doesn't allow it to inflate fully at the crossover.
when I run al80's I use a SS cam band to get the 1lb on the tank, and then run it to my waist belt instead of the butt rails to keep it down, some counter it with a tank weight, to each their own. It certainly isn't dangerous and in many locales steel tanks aren't an option. Removing the buttplate isn't an option if you're using tanks that stay negative in the butt, they have to hang from somewhere, and that somewhere has to be above the center plane of the diver for the tanks to sit in the right position. You can either have butt rails, or a tail plate on your crotch strap. I prefer having something a bit farther out because it allows the tanks to hang mostly down instead of being pulled in and up which can cause them to do funny things when kicking.
when I run al80's I use a SS cam band to get the 1lb on the tank, and then run it to my waist belt instead of the butt rails to keep it down, some counter it with a tank weight, to each their own. It certainly isn't dangerous and in many locales steel tanks aren't an option. Removing the buttplate isn't an option if you're using tanks that stay negative in the butt, they have to hang from somewhere, and that somewhere has to be above the center plane of the diver for the tanks to sit in the right position. You can either have butt rails, or a tail plate on your crotch strap. I prefer having something a bit farther out because it allows the tanks to hang mostly down instead of being pulled in and up which can cause them to do funny things when kicking.
OP
Texasguy
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I use alum tanks because it is all one has when diving on vacation. I don't want to get used to steel and then a whole vacation try to reinvent the wheel, I'd better get it under wraps at home. Once I'll get it figured out, I'll switch to steel. BTW, my vacation is in a month.
Alums I usually hook to the door handles when they are full, then @ about 800PSI I hook them to the sides of my belt to keep them ballooning up.
Alums I usually hook to the door handles when they are full, then @ about 800PSI I hook them to the sides of my belt to keep them ballooning up.
victorzamora
Contributor
Texasguy, I totally agree with you about steel vs alu for vacation diving. Al80s is all you can usually get on vacations. I've spent a lot of time trying to get my AL80 rigging right. It's still not there.
One thing I'll say is to not hook AL80s to your door handles. Edd teaches to put 3# on each camband at the bottom of AL80s and dive them like steels. It works VERY well. I don't like adding lead to my tanks, though...it makes them a pain to deal with. For AL80s, I've been hooking them to waist d-rings.....four in total (two per side), similar to the Razor mounting method.
djcheburashka, a "balanced rig" has nothing to do with trim or even "once axis." It's about being far too heavy or not. Being in trim is a two-axis proposition. Tank trim is a 3-axis proposition. It has nothing to do with "trapping air" (which doesn't happen on the SMS100) or any of the other crap you're referring to. OP is asking about stuff you can't answer from experience, so don't answer at all.
One thing I'll say is to not hook AL80s to your door handles. Edd teaches to put 3# on each camband at the bottom of AL80s and dive them like steels. It works VERY well. I don't like adding lead to my tanks, though...it makes them a pain to deal with. For AL80s, I've been hooking them to waist d-rings.....four in total (two per side), similar to the Razor mounting method.
djcheburashka, a "balanced rig" has nothing to do with trim or even "once axis." It's about being far too heavy or not. Being in trim is a two-axis proposition. Tank trim is a 3-axis proposition. It has nothing to do with "trapping air" (which doesn't happen on the SMS100) or any of the other crap you're referring to. OP is asking about stuff you can't answer from experience, so don't answer at all.
djcheburashka
Contributor
It's funny because I manage to dive with no but plate or tail plate, and with tanks that stay negative in the butt. And without attaching weights to my tanks when I dive al80s. It's tricky to get the tank trim right when you vary tank size, but really tbone you're missing like 5 years of progress here.
Texasguy-alums switch from negative to positive in salt *in the rear* closer to 2000psi than 800. The total tank doesn't become positive until later, but the rear of the tank becomes positive quite quickly.
Texasguy-alums switch from negative to positive in salt *in the rear* closer to 2000psi than 800. The total tank doesn't become positive until later, but the rear of the tank becomes positive quite quickly.
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pictures of this "progressive setup"? If it was 5 years of progress and it actually works, why are none of the manufacturers going to this type of system and why aren't the leading sidemount instructors going to it?
2200 psi is when the tank itself will be neutral, the butts start floating almost immediately, but the whole thing is positive around 2k. Certain faber tanks exhibit the same floaty butt behavior which makes them not suitable to leave on the butt rails during the dive.
2200 psi is when the tank itself will be neutral, the butts start floating almost immediately, but the whole thing is positive around 2k. Certain faber tanks exhibit the same floaty butt behavior which makes them not suitable to leave on the butt rails during the dive.
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