Few questions regarding fitting of a BPW

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TT_Vert

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I've read all the web pages how to set them up and I've got mine fairly comfortable. I have a few questions regarding the shoulder straps. I am using a hog harness and I've read that an easy preliminary test is to see if you can fit a fist between the straps and your shoulder and also 2/3 fingers from another source. My problem is that when I have it loose enough to fit 3 fingers the plate cannot be touched by reaching back over my shoulder. I'm wondering if it is my lack of flexibility or perhaps I'm doing something wrong. It seems the looser the shoulder straps the lower the plate would be and that seems to be the case with me. So how are you guys getting the requisite shoulder strap clearance w/o having the plate drop down too low? I don't want to have it too tight but I've read that it is loose enough when you can rotate your shoulders and it pretty much falls off. I'm not there but close enough where I think I can wiggle my shoulders out of the straps as I rotate my shoulders back. I'm a bit more muscular than average so this may be part of the issue but I don't know for sure.

Thanks for any input.

Dave
 
Sounds like you're pretty close to the proper adjustment. Definitely close enough to try a dive. For what it's worth, it's possible to achieve a good fit with a hog harness by leaving the shoulder straps relatively loose, cinching down the waist strap, and tightening up the crotchstrap. At least, that's the way I like it. As long as the rig feels securely fastened to your back and you aren't uncomfortable, that's good enough in my opinion.

I wouldn't obsess about it too much. If it feels too tight, loosen it up a little. If it feels too loose, tighten it up a little. Bear in mind that the straps might loosen up a little after they break in.

Enjoy the new setup...
 
Thanks much. I was just concerned about the BP height because they mention I need to be able to TOUCH the BP to be reasonable assured I could access my tank valve w/ the plate on. The BC is very secure and doesn't move at all really. I am doing some pool diving Sunday before my dive trip next week so I'll play with it some. Any opinions on anything to look for or any tests I can do?

Thanks

Dave
 
For single tank diving...
If you need to manipulate the tank valve while wearing the BP/W, you can push up on the bottom of the tank with your left hand and turn the valve knob with your right hand. But just because you can manipulate the tank valve, don't be complacent in your pre-dive and buddy checks. Having to turn that valve knob with your BP/W rig on your back is a really rare event. Normally if you have an issue with your back-gas, you'll just go to your alternate air supply, e.g., buddy's tank, pony.

For diving doubles...
Being able to reach your valve knobs to troubleshoot problems is part of standard operating procedure.
 
As BubbleTrubble said, with a single tank, you have a lot of flexibility about where you put the tank in the cambands. I had to put the bands MUCH further down on my tank than I thought (high enough to feel the first stage with my head) to reach the valve reliably.

In doubles, you are constrained by the holes for the bolts, so you only have a certain amount of leeway. Since you MUST be able to reach your valves, you have to adjust straps to permit that, and then fix everything else from there. But you can often lower the tanks more than you think, and still reach them.
 
Another thing that needs to be considered is that underwater the weight of the plate and tank is taken off and the rig usually is fairly neutral so reaching back and fondling your valve(s) is easier. Remember also that underwater your wing will be helping to pull up on the rig.
On land gravity pulls everything down so testing out position is not always accurate.
One way to simulate the position of the rig underwater is to back up to a bench and set the tank(s) down and take off enough weight so you can see where it will be riding when the weights off.
With adjustment, the rig should be tight enough that it doesn't flop all over but loose enough that you can get out.
Instead of putting both arms back and getting the rig to slide off behind you try lifting one of the straps away from the front of your shoulder/chest area and sliding the other hand/arm under the strap and out forward. This is much quicker and allows the harness to be a tad tighter for a better fit.
Some say you should be able to work your valves without having to reach back and push up on the tanks and other schools say it's OK.
I say whatever works.
With these Hog set ups I'm becoming more and more of a believer in using a crotch strap. My thinking is that a Hog harness absolutely depends on it, especially now with the growing popularity of sliding cinch systems.
 
If your waist band is in the right place and tight enough, the plate (even with tank and weights) will hold its place--at least this is my experience, unless I am wearing my TLS350. For me, it depends on the exposure suit. In a wetsuit or compressed neoprene drysuit (CF200), I can lock the waist strap without any sag in the plate/tank when standing up out of water--and the rig is so secure underwater that I don't need a crotch strap (diving a single tank). With a TLS350 (a very slippery trilaminate suit), forget about it--I can't get a really secure lockdown of my waist strap. Underwater the squeeze (esp when wearing 400g of thinsulate, which I don't need with the CF200) loosens even more my waist strap so that my first order of business at depth is to tighten it (and then I loosen it again at the surface for comfort during longer surface swims). And with the trilam suit I definitely need a crotch strap to hold everything in place, even with a single tank. With the crotch strap, the trilam is fine underwater, but my rig is definitely loose and sagging out of water.


I've read all the web pages how to set them up and I've got mine fairly comfortable. I have a few questions regarding the shoulder straps. I am using a hog harness and I've read that an easy preliminary test is to see if you can fit a fist between the straps and your shoulder and also 2/3 fingers from another source. My problem is that when I have it loose enough to fit 3 fingers the plate cannot be touched by reaching back over my shoulder. I'm wondering if it is my lack of flexibility or perhaps I'm doing something wrong. It seems the looser the shoulder straps the lower the plate would be and that seems to be the case with me. So how are you guys getting the requisite shoulder strap clearance w/o having the plate drop down too low? I don't want to have it too tight but I've read that it is loose enough when you can rotate your shoulders and it pretty much falls off. I'm not there but close enough where I think I can wiggle my shoulders out of the straps as I rotate my shoulders back. I'm a bit more muscular than average so this may be part of the issue but I don't know for sure.

Thanks for any input.

Dave
 
I've got my crotch strap secured but not tight enough to pull down on my waist strap at all. I'd say I have 1/2" or so between my crotch w/ my 3mil on and the strap. i read that I want the crotch strap loop to be about 1" above the webbing it attaches to in order to get about 1" of clearance in the crotch area. Tomorrow I'm doing a little testing in a freshwater pool so I'll play with it some. Can you guys recommend what I should look for, what I don't want to see, etc.? Unfortunately the pool is only 10' deep so I'm only going to be playing around and since I dive in salt water 100% of the time I can't really do any buoyancy checks that will be relevant in the ocean. I'll still do a buoyancy check at 3000 psi and 500 to see but based on my math and the fact w/ a bcd and my 3mil shorty/boots in salt I use 7 lbs I'm HOPING the SS backplate and webbing will allow me to go w/o a belt in salt. From what I read the SS plate is about -5, not sure what the webbing is. I also don't know for sure what the bcd I was using was at buoyancy wise. People are saying between +1 to +3 lbs so if that is the case I am between -6 to -4 w/ the old bcd and the 7lbs of lead I was wearing. Which would put me close to where I anticipate to be w/ the SS BP at -5ish.

NOTE: I'm not mentioning the buoyancy of the reg, fins and exposure suit because those will be the same dive to dive.
Thanks
Dave
 
For crotchstrap adjustment, just go with what feels good. If the tank feels like it's not anchored securely enough to your back, tighten the crotchstrap. You'll know if it's too tight. :D
Unfortunately the pool is only 10' deep so I'm only going to be playing around and since I dive in salt water 100% of the time I can't really do any buoyancy checks that will be relevant in the ocean.
The pool is plenty deep to do a weight check.
FYI, it's possible to get close to proper weighting in saltwater by doing a freshwater weight check.
Step #1: Weigh yourself + all of your gear.
Step #2: Determine the appropriate amount of lead for freshwater.
Step #3: Add an amount of lead equivalent to 2.5% of your total dry weight (you + all of your gear, including wetsuit/BC/tank/etc.).
That should get you fairly close for saltwater weighting.
I'll still do a buoyancy check at 3000 psi and 500 to see but based on my math and the fact w/ a bcd and my 3mil shorty/boots in salt I use 7 lbs I'm HOPING the SS backplate and webbing will allow me to go w/o a belt in salt. From what I read the SS plate is about -5, not sure what the webbing is. I also don't know for sure what the bcd I was using was at buoyancy wise. People are saying between +1 to +3 lbs so if that is the case I am between -6 to -4 w/ the old bcd and the 7lbs of lead I was wearing. Which would put me close to where I anticipate to be w/ the SS BP at -5ish.

NOTE: I'm not mentioning the buoyancy of the reg, fins and exposure suit because those will be the same dive to dive.
Yeah, as long as you aren't changing your exposure suit, you might not need a weight belt at all with the SS BP.
Just make sure you repeat the weight check in saltwater. Enjoy the new gear...
 
I'm on board with what the others have said. I think you are close enough. You did it "by the numbers" so now use the rig in the water and at the surface. Adjust as required. Don't get too focused on hard and fast "rules". Instead, just dive. You'll find the sweet spot.
 
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