Wing bladder size and suggestion for backplate/harness system

[Eric Sedletzky]

That's a pretty streamlined 40 lb wing. I doubt the taco would be significant.

That’s what I use and there is no taco effect.

 

[inquis]

I m diving currently in an Apeks black ice which is quite bulky and I’d expect maybe more positive than smaller BCs.

This is easily quantified with a luggage scale by measuring when sunk (leave the lead in it), measure the weight of the lead alone (or accept the markings as accurate) and the difference is the BC buoyancy. Make sure to vent the BC when submerged.

ETA: a hot tub, pool, or even a large recycle bin can be used if there is no nearby dive site.

 

[Wibble]

This is easily quantified with a luggage scale by measuring when sunk (leave the lead in it), measure the weight of the lead alone (or accept the markings as accurate) and the difference is the BC buoyancy. Make sure to vent the BC when submerged.

ETA: a hot tub, pool, or even a large recycle bin can be used if there is no nearby dive site.

Volume matters as much as weight. Most BCDs have loads of plastic which makes it light in the water.

 

[inquis]

Most BCDs have loads of plastic which makes it light in the water.

Which is why you weigh it in the water to get a bottom-line buoyancy measurement, which includes both volume and mass effects. (I can't tell if you're disagreeing with or elaborating on what I said. Apologies if the latter!)

 

[Wibble]

Which is why you weigh it in the water to get a bottom-line buoyancy measurement, which includes both volume and mass effects. (I can't tell if you're disagreeing with or elaborating on what I said. Apologies if the latter!)

Soz. Just re-read your post "...measuring when sunk...."

Yes.

 

[Ontwreckdiver]

Thanks everyone for all the info. I think I’ll definitely need to wait until I know how much weight I need when diving in my drysuit before making my decision. Although I might have to adjust that a bit considering I m diving currently in an Apeks black ice which is quite bulky and I’d expect maybe more positive than smaller BCs.

I’m now also looking at the OMS smartstream system with 32lb wing. Any experience with this system or brand?
I like this because it has integrated trim weight pockets on the backplate, an adjustable harness (any thoughts on these?).
It doesn’t have a steel STA which would add a little extra lead needed but I’m also not sure whether the steel STA are better/needed than just having the wing attached to the plate via the bands and then having little bars on the wing to keep the tank in place?

Sorry if I keep changing the topic of the thread but you guys have been so helpful I’m trying to get as much info as possible.

Sub Gravity has Backplate trim weight pockets. Backplate Trim Weight Pockets (pair) - SubGravity