Mach V on DSS/Hog Setup

[CrazyMike]

Hello everyone. I am a victim of my own impatience, so I thought I'd share some of my experiences - maybe it will help you make some good decisions.

In my quest for the 'right' BC setup for me, I have done the following:

Bought a DR Transpac with Rec Wing at about 10 dives experience. After about 35 dives, I became annoyed with having a bit too much bulk when packing up the outfit, rear dumping, and face-forward surface boyancy. I also found myself feet heavy and the tank was constantly banging the back of my head. I'm 5'10 and pretty much average torso/legs and in pretty good shape - nothing unusual there.

I thought the steel 119's I bought might help some of these problems by shifting the CG up a little, but the tank would still hit my head.

So, after some research, got antsy-in-the-pantsy about this Mach V everyone is raving about. I thought this was the answer to my problems. Didn't look like anyone tried it on a Transpac so I gave it a shot. Got my Mach V (30# Sig Series) and Oxycheq lightweight STA (thanks Patrick) and bolted it up (used lock nuts as the wing nuts won't work on the transpac). Right away I realized a bit of a folly. While the wing was everything everyone said it would be (a true work of art), the entire ~50# of a full HP119 would be supported by the two grommets embedded in the Nylon 'backplate' of the Transpac. The nylon is tough enough to handle the load (at least for a few seasons of diving if I really wanted to go for it) but I also predicted it would be super 'floppy' since the tank has essentially no lateral support by using a STA. Dove that setup last week and yep, I was correct in that assumption. I CAN say that on the surface the Mach V felt just great and very well balanced below, but the tank was wayy too floppy laterally on the Transpac. Back to the drawing board...

After MORE research here on SB and some discussions on SB and with Tobin, I opted for the DSS Kydex plate and basic hog harness (I found myself stuggling with the extra D Rings and excess adjustment straps on the Transpac, thought I'd try the hog). I put D rings on both hips to keep the 16# DR transweight pockets in place, and tried out the new setup today. MUCH better! This was my first experience with a true BP/W setup. Finally felt stable again (although I never had lateral stability problems with the orginal Transpac/Rec Wing setup - the tank always felt solid). I really liked the simplicity of the hog harness and found it super easy to take off and replace underwater. Had some turtling effects if I let myself roll too much, but it was easy to prevent and recover from if I let it roll me over. This was to be expected with the big steel. However, my biggest and only real problem: the first stage hitting my head was worse than ever! I could only look straight down. Looking forward at all while swimming horizontally resulted with the first stage pressed right in the middle of the back of my head. Ugh.

So what are my options? I know there has been some discussion on this before. I think I have the following options:

1. Lower the plate. It is a meduim plate and is already so low that I can get a finger on it by 1/2" or so. How low can I go? From what I can tell, the plate is in perfect position on my back according to several sources. I don't think the plate will be in a correct position if lowered much. On the plus side, if lowering the plate would work, I won't need to buy anything new. This would be best, but not sure its an option.

2. Get DR STA and cut slots (Nemrod has pioneered this option). This allows me to keep the Mach V wing and hog setup as is. But is this the best solution? BTW, the STA I have now is already in the lower two holes in the DSS plate. Can't take it lower and the slots in the Oxycheq lightweight STA are below the bolt holes. A 2-piece won't get the top slot any lower. I think my biggest concern is adding weight. I don't want to add a pound If I can help it, although, one might be liveable. Not sure how the Oxycheq and the DR compare weightwise. I found out today by testing, I don't need any ditchable weight with 3-mil farmer johns and 3 mil long sleeve shorty with 3 mil hood. Weight is everything now.

3. Sell the Mach V and buy DSS wing (either 26# Torus or 30# LCD). Using the band slots in the DSS plate will allow me to drop the tank a little more than 2" than the Oxycheq lightweight STA allows. Additionally, I'm guessing the DSS wings will have the same buoyancy as the Mach V, so I can eliminate 1-2 pounds by getting rid of the STA. Bad part is, I have to buy/sell MORE equipment.

I'm kinda leaning toward the Dive Rite STA option, since it won't cost me much more than $20-30 and some time and will ultimately accomplish my goals here. I really do like the Mach V shape and quality so I'd like to keep it. Guess I'll give it some more thought.

Again, I don't want to sound negative about any of the products I've bought and used. I think it is all top-notch and high quality gear - I couldn't be happier with the customer service and product quality from the above companies. I'm just trying to optimize a setup that is perfect for me. Having some growing pains as I'm going along. I wanted to post here for your reading pleasure and consideration. Stay tuned for more...

 

[Captain Fathom]

One of the problems with all STAs is that they hold the tanks to high. I frankly don't care what anybody says about this that I am wrong. It is a personal preference in part and further the current fashion of wearing single tanks hiked up behind the head is problematic at best. It destroys trim, is uncomfortable, potentially a brain basher and all in all has nopositive benifit. So, why do they continue to build STAs with the slots positioned incorrectly--beats the heck out of me. The upper slot needs to be lower and that is all there is to it. At least offer the option by providing two upper slots to allow greater adjustment. Notice in the pic below the conventional upper slot position with both two piece and single pice and note the added upper slot. My tanks do not hit my head, I have excellent trim.

On new Faber LP 85

OOPs, I used my wife's screen--darn that--oh well, she won't mind.

 

[cool_hardware52]

Mike,

I think you know what my first recommendation would be

Before you buy anything else here's a couple thing you can try;

1. Rotate your tank about 20 degrees counter clockwise as viewed from the top of the tank. That might move the first stage to the left enough to give you the clearance you seek. Costs nothing, and makes reaching the valve a little easier.

2. Slip the top camband under the STA instead of thru the slots in the STA. That will allow you to move the top camband down. Costs nothing

3. Get used to hitting your head. If you ever move to doubles you will find you have a dent in your hood shaped like an Isolator valve handle. Only costs you a dent in the back of your noggin.

Good luck,


Tobin

 

[realdiver7]

Since you already have the DSS Kydex BP, if you buy the new Oxycheq Mach V wing with cam slots, it will work just fine with the DSS Kydex BP, and you won't need a STA. Just remember not to overtighten the cam bands because the Kydex will bend outward towards the tank a little.

As expected, the Oxycheq aluminum BP/Mach V with cam slots/Hog harness setup all match up perfectly, and solves the mix-match problems associated with mixing and matching.

 

[diver 85]

Mike,

I think you know what my first recommendation would be

Before you buy anything else here's a couple thing you can try;

1. Rotate your tank about 20 degrees counter clockwise as viewed from the top of the tank. That might move the first stage to the left enough to give you the clearance you seek. Costs nothing, and makes reaching the valve a little easier.

2. Slip the top camband under the STA instead of thru the slots in the STA. That will allow you to move the top camband down. Costs nothing

3. Get used to hitting your head. If you ever move to doubles you will find you have a dent in your hood shaped like an Isolator valve handle. Only costs you a dent in the back of your noggin.

Good luck,


Tobin

Tobin, when reading the OP's post, I kept thinking will this happen on the rig we 'talked' about earlier today?? Was just a wonderin'........

PM me if you prefer ......

.................Joe....diver 85............

 

[JessH]

2. Slip the top camband under the STA instead of thru the slots in the STA. That will allow you to move the top camband down. Costs nothing

This is what I was about to suggest. It should allow you to lower your tank enough to not hit your head.

I use a two piece STA so I drilled an additional hole in my BP to allow me to lower the top cam band and it solved all of my problems(and no this did not require adding an additional hole to the wing). When diving steel tanks I trim out well and I can still reach my valve. With aluminum tanks I add a trim weight up top and then they work too.

As Tobin said you don't need to buy anything else. The components you have have are great and they should be perfectly compatible.

~Jess

 

[kidsdream]

You might try a Hammerhead STA and save a couple of $$ and save the hassle of cutting the holes yourself (just call them to verify that there are still 3 sets of slots in their current product).

One thing that did "hurt" you a bit is the DSS Kydex plate's lowest mounting hole is nearly1" higher than on a Hammerhead or Dive Rite plate.

After playing around with combinations of 3 wings and 4 plates, the DSS plate (at least if you want to usa STA is not fully compatible with a lot of other products.

Also if you wanted to drill another hole in the Kydex plate you would have to go much lower, as about 3/4" under the current hole is the rivet that holds the metal backbone to the plate itself.

The DSS products are very nice (but I do think the design of the Mach V Sig is nearly perfect for me), but are best used as part of complete DSS system.

 

[CrazyMike]

Cool, thanks for all the comments. I think Tobin's suggestion of mounting the top band under the STA will likely be my workaround for the near-term until I decide to completly 'fix' the problem. Plus it will give me an idea of how the trim will behave in that position. Maybe it will become my permanant solution...

if you buy the new Oxycheq Mach V wing with cam slots

Sounds great, but I didn't think this was officially announced or anything beyond a rumor...

I use a two piece STA so I drilled an additional hole in my BP to allow me to lower the top cam band and it solved all of my problems(and no this did not require adding an additional hole to the wing).

I really liked this option, but I would have to put a hole in the Mach V as well. This would be the cheapest and potentially easiest solution (as far as a more permanant fix.). I hate to put a hole in the wing, but if I can get it done correctly with a grommet, this might be the way to go and it could save a little weight over the DR STA option.

You might try a Hammerhead STA

Guess I'll give them a call on Monday, but I think that even if they have one with 3 slots, it is stainless steel and will be too heavy for my application.

Also if you wanted to drill another hole in the Kydex plate you would have to go much lower, as about 3/4" under the current hole is the rivet that holds the metal backbone to the plate itself.

Yeah, I thought of this too, but I need to go about 2 inches down. This is fine for the top hole, but here is no plate left to drill on the bottom end - unless I redrill the STA too. Gotta find one of those square drill bits

Nemrod, I am curious about your DR STA workaround. How much does it weigh? Is it 2# or less? Also, it looks like you have the wing mounted on the wing's bottom holes. If you wanted, is the STA short enough to move up to the top holes in the wing or are their clearance issues? Just thinking out loud but was wondering if I found my trim was still a little feet-low, I could move the wing down to the bottom holes to move the bias down a little. Maybe it buys nothing, but was curious...

 

[GreenDiverDown]

Mike...

What reg are you using?

And...

Is it DIN or yoke?

And the tank valve... DIN or yoke?

 

[cool_hardware52]

Tobin, when reading the OP's post, I kept thinking will this happen on the rig we 'talked' about earlier today?? Was just a wonderin'........

PM me if you prefer ......

.................Joe....diver 85............

Why? The OP has built a "Frankenstein" You and I discussed using all DSS gear, i.e. a DSS plate with a DSS wing. There is no need for a STA with our gear. It is the STA that creates the problem. The camband slots in both our wing and Plate are much closer together than they are on most STA's That allows a much greater range of tank positions.

Tobin