Advokat:
I'm limiting my choice of BP/W to these two brands. I'm thinking of getting Aliminium backplate and a 60LB wing or larger, as I'm a bit concerned that 60LB wing will not lift twin 15l steel set up and a stage bottle. Can I get some opinions on these two brands and their set ups?thanks
There are many good quality Back Plates and wings available today.
Before selecting a type or brand I'd suggest spending a little more time analyzing your application. Keep in mind that the single most important factor affecting ballast requirements and lift requirements is the buoyancy of your exposure suit, not the material of your tanks.
There are certainly applications for 60 lbs lift wings, and also for Aluminum back plates, but to use the two together would be an unusual choice.
Lots of lift implies lots of gas and or ballast. If you need lots of ballast why use a lightweight plate?
Assuming you are using 232 bar steel 15L tanks they will be close to neutral when empty (if you are using other tanks this example could be flawed)
Your tanks will hold about 20 lbs of gas.
You need to start your dive negative by the weight of your back gas, + a few lbs., lets say about 22 lbs.
You also need enough ballast to offset the buoyancy of your exposure suit. I'll assume a shell dry suit with medium weight undies on a normal sized person, typically that results in about 20-24 lbs of buoyancy.
If you need to be 22 lbs negative, after adding enough ballast to get your 24 lbs suit neutral than you need 22+24 = 46 lbs of total ballast. Your tanks are close to neutral, so they don't contribute much ballast, and even with dual regs (~5 lbs) and tank bands and manifolds (~5lbs) can light (~3lbs) and a Stainless steel back plate and harness (~6 lbs) you will still be far short of the required total of 46 lbs. An al plate just makes this shortfall greater.
Again assuming your suit is +24 and your tanks are near neutral when empty your rig will be at most about 39-40 negative withfull tanks, if all your additional required ballast is placed in a weight belt. Your rig might be as much as -50 if you add ballast to the rig (v weights, etc.)
On the other hand if you plan to use this gear in warm water, then your exposure suit will be much less buoyant and you will need less ballast and less wing lift. That's what makes me question an al back plate with a 60 lbs wing.
Tobin