60# wing?

[RJP]

Indeed, you will not catch me arguing against the declining marginal utility purchased by the extra $250 or so that a Halcyon wing costs. But there is a difference in utility and given all that I spend on diving, a couple extra bills for a small improvement in wing quality is an absolute no-brainer.

Too bad the OP can't find some kind soul on SB to sell him a gently used Halcyon doubles wing for less than the cost of a new DR wing.

:d

 

[eelnoraa]

My calculation:

-23# for full double HP120s (manifold and bands may actually be heavier than I estimate)
-18# for ballast (SS BP + weights - this is what I use with a drysuit and single HP120 in fresh water at 39F. I might need less weight when adding the doubles setup, but I might want more weight for longer/colder scenarios, so I figured I'd just stick with 18# ballast, and plan for fresh water as worst-case scenario)
-6# for fins (estimate for F1 fins)
-8# additional ballast to compensate for 2 x AL80s

hmm, I don't think any of these play in wing lift calculation. What you need to consider is the weight of gas you are carrying and the max buoyancy your drysuit can lose if fully flooded. You may still need 55lb but you should do the right calculation. If your instructor tell you this is how to do lift calculation, maybe it is time to find a new instructor. Or at least give Tobin@DSS a call.

 

[RJP]

the max buoyancy your drysuit can lose if fully flooded

Well, seeing as water is neutrally buoyant... a flooded drysuit can't really "lose" buoyancy.

 

[eelnoraa]

you are technically correct. But a drysuit can be +20 when not flooded, and maybe close to 0 (neutral) or small positive when fully flooded, so the change in buoyancy should be counted, right?

 

[tursiops]

OP, I've got a not-much-used IDI SEAIRA, dual-bladder, bungeed wing, rated at 80 pounds lift, that you can have for $100.
I'm pretty much local to you, so no shipping charges.

 

[stuartv]

Better construction on the Halcyon wing, and a lifetime warranty on the welds/seams of the bladder versus DR's pathetic 'we have no obligation to you after one year' approach. If you really care about the $200, sure, DR is fine.

I have no experience with DR. I just see that this wing has a "WORRY-FREE LIFETIME GUARANTEE" and their website seems to explain that to mean what it sounds like.

So, what is the reality? I realize it could be very different than it sounds. I called Hog yesterday to ask about their 58# horseshoe and I learned that their 10-year Pinch Flat warranty doesn't at all mean what it sounds like. Jack explained that (to Hog) a pinch flat is not the flat you get from dropping your BP onto your wing and pinching the wing between the plate and a hard surface. That is user error/abuse and not covered. He said that (to Hog) a pinch flat is what you get when a fold in the bladder eventually turns into a crease and the crease eventually becomes a crack and starts to leak.

Might be time for your instructor to take some classes that will teach him about buoyancy control and trim. At minimum someone needs to explain the buoyancy characteristics of an AL80 to him.

PS - ask him if there are any other, more important reasons to sling bottles on the left.

---------- Post added July 7th, 2015 at 05:18 PM ----------



Time to replace the monkey with a qualified instructor.

Ah, yes.... ScubaBoard, where the answer to any question is "your instructor is incompetent." Or, "Petrel." One or the other, sometimes both.

Thanks for your reply that provided no help whatsoever. BTW, I could be wrong, but my reading of specs leads me to conclude that 2 full, slung AL80s are going to be somewhere around 4'ish pounds negative (guesstimating buoyancy of the rigging). It could just be my inexperience, but hanging 4# on a diver's left side sounds to me like more than enough weight to throw off his/her trim.

Also, in the expression "monkey see, monkey do," the word monkey refers to myself.

Indeed, you will not catch me arguing against the declining marginal utility purchased by the extra $250 or so that a Halcyon wing costs. But there is a difference in utility and given all that I spend on diving, a couple extra bills for a small improvement in wing quality is an absolute no-brainer.

What is the difference in utility that the Evolve gives as compared to the DR Classic EXP? What utilization will I achieve with an Evolve that I couldn't achieve (or as easily) with a DR Classic?

---------- Post added July 8th, 2015 at 09:36 AM ----------

hmm, I don't think any of these play in wing lift calculation. What you need to consider is the weight of gas you are carrying and the max buoyancy your drysuit can lose if fully flooded. You may still need 55lb but you should do the right calculation. If your instructor tell you this is how to do lift calculation, maybe it is time to find a new instructor. Or at least give Tobin@DSS a call.

And how do you propose to figure out the buoyancy I can lose from my flooded suit?

I did it by assuming that I am neutral, when naked. Then I add gear of known buoyancy (e.g. a tank, BP, and weight belt). And I figure that whatever that buoyancy is must be the equal and opposite of the lift my suit is providing.

Or, in other words, if I add up all the negative buoyancy gear, and my only positive buoyance items are my suit and my wing, and then assume that I have a catastrophic failure immediately after my descent to the bottom and my dry suit is not able to provide any lift at all (I know, tbone, but worst-case scenario here), I want my wing to be able to lift it all, right? This is all assuming that I am correctly weighted in the first place, of course.

I note that calculating the max buoyancy loss of a drysuit seems to be not as straightforward as doing the same thing with a wetsuit. On any given day, I could put on more undergarments, add more air, and add more weight to compensate. So, it seems like the only reasonable thing to do is assume the worst case of the suit buoyancy goes to 0 at all depths and base the lift calculation on the negative buoyancy of everything else one is carrying. Which has the corollary that, if, on a given day, I DO add more undergarments and more weight, I need to re-check my numbers to make sure I still have enough wing lift capacity.

What is wrong with this approach?

ps. I haven't started the Tech class yet, so my instructor has not done anything (yet) to teach me how to do a lift calculation. He just recommended bypassing a 45# wing and going straight to a 60, to avoid buying a bigger wing later. He also said that I could wait until class started, go over this with him in more detail as part of the class, and still have plenty of time to buy what I need before our first time getting wet.

 

[CptTightPants21]

Getting either a good condition used Evolve or a DR wing is 6 in one and 1/2 a dozen in the other, especially for your first doubles wing. I was looking at getting the DR 60, until I found a great deal on a used Oxycheq 50 that I picked up for $115.

I think eelnoraa comment was off base and just an excuse to attack you. You can google lift calculations on this site and Tobin (cool hardware52) posts his methodology all the time. You basic methodology was fine, your numbers were a bit off.

Specifically, the -18 ballest, looks ridiculously high. You probably won't need much weight with the doubles, and you should probably switch to aluminum back plate to lower your ballast and give you more options for adding trim weights if you need them without becoming over weighted.

Assuming zero buoyancy from dry suit and tanks

Full Faber FX-120s (are these the tanks you are diving?) are -17, add -6 for regs and manifold (so tank number was fine)
-2 for canister light
-5 for aluminum plate, reel, accessories (al plate is -2.5lb)
-8 for double AL80s,
-4 for regs on those tanks
-3 for fins. No way are F1 fins the equivalent of a SS backplate and even -3 might be a pound too heavy

That gives you -45 lb and assuming double stages. You are far away from even thinking about stage bottles and by that time you are ready you will have probably moved onto another wing. Anything in the 50-60 range will be more than enough for your needs.

 

[stuartv]

Getting either a good condition used Evolve or a DR wing is 6 in one and 1/2 a dozen in the other, especially for your first doubles wing. I was looking at getting the DR 60, until I found a great deal on a used Oxycheq 50 that I picked up for $115.

I think eelnoraa comment was off base and just an excuse to attack you. You can google lift calculations on this site and Tobin (cool hardware52) posts his methodology all the time. You basic methodology was fine, your numbers were a bit off.

Specifically, the -18 ballest, looks ridiculously high. You probably won't need much weight with the doubles, and you should probably switch to aluminum back plate to lower your ballast and give you more options for adding trim weights if you need them without becoming over weighted.

Assuming zero buoyancy from dry suit and tanks

Full Faber FX-120s (are these the tanks you are diving?) are -17, add -6 for regs and manifold (so tank number was fine)
-2 for canister light
-5 for aluminum plate, reel, accessories (al plate is -2.5lb)
-8 for double AL80s,
-4 for regs on those tanks
-3 for fins. No way are F1 fins the equivalent of a SS backplate and even -3 might be a pound too heavy

That gives you -45 lb and assuming double stages. You are far away from even thinking about stage bottles and by that time you are ready you will have probably moved onto another wing. Anything in the 50-60 range will be more than enough for your needs.

Thanks, Capt!

My 120s are old Genesis tanks. In other words, AFAIK, E7-120. Neutral empty, -10.5 full. My -23 number didn't allow enough weight for manifold, bands, and regs, I think.

The -18 ballast was determined empirically. My DSS BP is 6# and I have the 8# weight plates attached. With just one HP120 and my drysuit, I needed more weight. I added 4# on a belt and was good after that. I realize it might be more than I need once I add a second tank and related hardware. But, I also might add more undergarment and air in my suit, too, to last longer in 39F water. Until I try it, I don't know how to know for sure what ballast I'll end up wanting, so I was erring on the side of conservatism for my math.

Also, my thinking is/was that my weighting needs to be enough for the end of the dive, with empty tanks. Thus, adding a second tank, which is neutral when empty, wouldn't affect my weighting. But, the manifold/bands/etc. would, so maybe that might knock 5# off my required ballast? Which, again, I might end up keeping that 5# of ballast to compensate for more undergarment. Regardless, I can knock 8# off by removing the weight plates from my BP, so it still seems like a SS BP is okay.

Another thought I just had that maybe gets to your point? I could use less ballast than I am thinking because, at the end of my dive, when I'm doing deco or safety stops, I could also let a lot of air out of my drysuit, as I might expect to not need as much thermal protection at that point? Thus compensating for (near) empty tanks without having to carry extra ballast?

Regardless of all that, it seems that all signs agree that, in anticipation of eventually wanting to sling 2 x AL80s, I should get a wing in the 60# range, which is the main thing I wanted to confirm. Thank you again for that.

The only remaining question I have is one from earlier: Is there any reason to spend more than $200 on the DR Classic? I've asked what, specifically, makes the Halcyon better - not what makes it worth an extra $290, but what makes it better - and the only answer I've gotten is "quality", with no details on what that means. Does that mean it's less likely to break in some way? Less likely to get a tear, puncture, or pinch flat? It's more streamlined in the water? And if it's less likely to break, is that saying the DR will probably break within 2 years and the Halcyon will probably not break until at least 5 years (i.e. a big difference)? Or are we nit picking about minor differences in how long they'll both likely last before the first repair is needed?

Or is it a customer service issue? One person slammed DR while another praised DR. Nobody has really commented on how well Halcyon takes care of it's customers. The fact that I could actually buy a spare bladder from DR to carry with me is definitely a point for them. I don't know about Halcyon, but I know at least one other manufacturer that insists you return the whole wing to them to let them fix any bladder problem, rather than selling and shipping you a replacement bladder.

 

[tursiops]

My 120s are old Genesis tanks. In other words, AFAIK, E7-120. Neutral empty, -10.5 full. My -23 number didn't allow enough weight for manifold, bands, and regs, I think.

Depending on the vintage/manufacturer of your 120s, your number could be way off. For sure, they are not E7-120. What is the full info stamped on the tanks, the tank diameter, and the size of the valve threads? I'll bet it says 3500, not 3442, which means they are not E7s. If they were made by PST they are different than if they were made by Asahi.

 

[CptTightPants21]

Assuming you really want to focus on doubles stages, etc then anything 55-60 would be fine.

What is the difference between a porsche and maserati? That's the difference between DR and Halcyon. And I don't even now who is which in that example. If you are buying new and "right now" go with the DR. If I had a choice between a new DR and a slightly used Halcyon 60, I would pay up for the used Halcyon because enough people that I trust have said the quality is better and I am patient when it comes to buying equipment so I can wait for good deal to pop up. Dive rite is an excellent company and I have no issue using their equipment, it is just that when you have two choices, someone has to "lose".


What you really should do is borrow your instructors wing or someone else equipment and figure out how much weight you need. This guess work with weight plates and other items just doesn't work, but like I said 55-60 is basically what you need to be on the safe side.