Pls help about this new BP/W set up

[Bom]

Hello,

Yesterday I just had chance to test the new BWP set up in the pool. It is Apeks travel plate with DSS Torus 17 wing and DR 13" STA. I did have few problems with the setup.

1.While floating on the surface vertically, my head did not touch the first stage when I look up. But when I dived horizontally under the water, the first stage seems to move up to my head and I couldn't look up front properly because my head hit the 1st stage. (1st stage is AL Legend LX.)
2. On surface, my body did not float as high as when I used DSS SS plate and DSS wing. I don't know why. On land, I measured the wrist strap of both rigs and they are about the same height so I guess both plate are about the same position in my back.
3. Under water, I felt that using soft plate was not as stable as SS plate and my body roll over pretty much (left-right). Is it normal for soft plate? or what cause the roll over?

Thank you very much for helps,

Bom

remark
My plate is about the same position as figure 1 in this link
BAUE How To Size a Backplate

 

[NAM001]

Location of center of mass or gravity is what causes the roll over. I don't k now how much you weigh or such attributes so I will have to do some guessing.

1st is it fair to say that you use less air in the wing when using the non steel BP???? If so then,,,,,, before, you had air in the wing and it provided a lift on the tank keeping the tank above you. the tank acts like a lever to roll you over. It happens when )(exaggerating) the tank is bigger than you are. so if you are 100# and wearing a steel tank that is -10 when full it will roll you upside down. Unless you have your wing inflated to provide 10# lift hold the tank on top. Once you went to the soft BP you took of say 4# of BP weight and hence gave up 4# of wing lift to compensate. your center of gravity moved closer to the center of the tank instead of the center of your chest and the lever effect took over.

Assuming I am a lucky guesser, then you need to put some weight on the front of your rig. Anything to put on say 5# negative on your gut to make the center of gravity move back from the tank , to your chest. perhaps 3# on the belt up front and then you will have to put 3# lift in the wing to comp for it. Between the 2 (3 weight and 3 lift) you will have a 6# change in the leverage that will reduce or eliminate the rolling problem.

 

[TSandM]

It seems strange for the first stage to be higher when you are horizontal, since when you are floating at the surface, the lift from the wing will tend to push the rig up as much as possible, limited by the crotch strap. So I'm not sure what's going on there, but some photos would help.

A soft plate is never going to keep the tank as stable as a metal plate, and if the tank has the ability to shift, it will tend to roll you.

Is it possible that the wing is sitting in a different position on the soft plate, compared with the metal one? If so, that could affect how high you float.

 

[RJP]

A.) Does the rig have a crotch strap?
B.) Is your first stage mounted pointing UP or DOWN?

 

[Yellowdog]

I dove with a Halcyon Traveler recently and I had the same problem with my head hitting the first stage on one of my dives. I thought that I had strapped the bpw to low on the tank but when I got back on the boat I realized that this was not the problem. The Traveler has the Cinch system built in and I had tightened the shoulder straps a bit tighter than usual, moving the plate up on my back. Since then I added a tri glide to the webbing to stop the shoulder straps where I want them. I was surprised at how subtle a difference in tightness in the shoulders changed the position of the plate on my back. I am not sure if your harness is adjustable but try to loosen the shoulders and see if that helps.

 

[Bom]

Thanks guys for helps, finally I solved the problem. I tried it again yesterday with longer harness so plate was a bit lower than the 1st time. I also readjusted the crotch strap. This time it was perfect.

KWS; tank is size 80. I dive with this size every time without problem so I think it was due to my new setup, not about tank. Thanks for your help

TSandM; yes I don't understand why it moved up higher on horizontal too. I guess it would be from improper webbing and crotch strap setup because I readjust everything and it worked fine.

RJP; 1st stage is upward position.

Yellowdog; Thank you very much for sharing your experience. After reading your comment, I readjusted everything and my problem were disappeared yesterday.

I had new minor problem yesterday. They webbing on the top of the plate seems to loosen up quite easy. How to proper do the webbing for 2 seperated harness L and R?

Thanks

 

[RJP]

RJP; 1st stage is upward position.

Or as we call it in the trade... "updside down"



Reverse it so it points down.

 

[cool_hardware52]

Hello,

Yesterday I just had chance to test the new BWP set up in the pool. It is Apeks travel plate with DSS Torus 17 wing and DR 13" STA. I did have few problems with the setup.

The camband slots on a DSS plate are *much* closer together than they are on most STA's Using a STA, which we do not recommend, will limit the range of adjustment available for your tank relative to the back plate, compared to using the DSS plate.

One of the primary benefits of a rigid plate is tank stability, the plate and tank are secured together and the plate takes the roll out of the tank. I never understood "soft" plates. You end up with a fabric BC with a Hog harness....

While I routinely recommend the BAUE website as a great resource, and fine place to learn about how to adjust a Hogarthian harness there are a couple things I'd change.

Positioning the top of the plate based on being able to touch while reaching over your shoulder is unreliable, as it varies with the individual diver's flexibility. I have daughters that can join hands behind their back, with one hand reaching down from above and the other reaching up from their waist. Don't be constrained by the "touch the plate" picture. Try moving the plate up and down to solve your problem.

Tobin