Project 'Frankenstein' - My DIY Sidemount Trial

DIY Sidemount, project 'Frankenstein' nearly complete.

32lb Singles Wing (OMS copy), with OMS Profile Adaptor and ali backplate/Hog Harness (DiveRite).

The wing itself was my old, old, single-tank wing.. it's taken quite a hammering from wreck dives over the last 3 years.. all the side-panel stitching is protected by aqua-seal (you can see...messy!)... as this prevent/reduces abrasion and splitting along stitching. It's a donut design, very similar to the OMS 32lb, but made here in the Philippines.

Took a bit of fiddling and customization to get the rig set up nicely:

1. The profile adapter is a bitch to fit snuggly (especially at the top)..some extra strapping made it sweeeet.
2. Swapped the left-hip pull-dump with the LPI.
3. Added 2x1lb trim weights to the upper shoulder straps.
4. Bungees (as pictured) were way too long... shortened considerably now.
5. The top pull-dump needed an extended toggle/string. It works fine from under the adapter cover. I've subsequently run the string through some narrow plastic tubing, to make it route easier and dump smoother. The toggle is also retained, but running it through a loop on the trim weight I've put on top of the shoulder strap (not hanging loose).

Still to do:

1. Swap the Ali hard-plate for a soft plate... probably an Oxycheq Ultra-Lite travel plate.
2. Try fitting some bungee loops under the buttplate for DSMB stowage...and test that for function.

End result - a nice, reasonably minimalist sidemount option, which retains my muscle memory from using a regular wing... and only cost $250 (already had the wing itself)...so adapter and spare backplate/harness were needed only.


I am in the middle of trialing it this week, whilst sitting in on an ANDI Tech Wreck course with Bruce Konefe, here in Subic Bay. Very good through the tighter restrictions...have started putting it through it's paces in that respect. The ali backplate isn't too much of a issue, as I am broad-backed anyway... but adding a soft-plate will reduce risk of wedging...and make it easier for travel.

It copes easily with 2x AL80, which is what I mostly use...there seems plenty of reserve for adding ali stages. The LPI/Dump swap works great...I don't use a lot of air in it anyway, but there's been no dramas adding/dumping air during the dive or ascent.

The only added weight necessary (I dive thin wetsuit) is 2x 1lb trim weights.

It's got nice inherent trim, stability and buoyancy... just like what I am used to in BP&W.


Photos taken before the first dives/adjustments. I'll add some more later, showing the sidemount in use, worn and after post-dive tweaking...

Thanks Devon! I love to see and read stuff like this.

Perfect devon, what stands out is the dive flag emblem stamped out in blue BP.

Maybe the bladder wont see so much abuse now using side mount.

VooDooGasMan:

Maybe the bladder wont see so much abuse now using side mount.

Click to expand...

Not judging by the last couple of days

I squeeze into more tight holes than a _________ in a __________. (insert your own funny metaphore, I can't think of any even remotely close to a 'PG' rating]

Looks like a nice start. The soft plate will be a big improvement!

Yeah... I can't get what I want (Oxycheq Ultra-Lite) in the Philippines at the moment... waiting for deliveries. Still, I'm happy to have concept-proved my idea... it means I can create a few more for rentals etc (open-water, not overhead).

I've got a broad back.. so the hard-plate doesn't really seem that it'd get wedged...I'd be breaking ribs before that happened I think... but why take the chance huh?

True. The soft plate will feel a lot better as well. Flexibility. No more back brace. That is why I love my harness setup.

What I see is that there's too much bouyancy too high up on the rig. Backmount wings are generally designed to keep a diver in a heads up position on the surface. When you've got backmounted doubles, the valves and regs are all right behind your head so more bouyancy there is ok. Now sidemounting, the valves should be right about at your armpits so the tank weight is shifted downwards and you need more of the wing down as close to your butt as you can make it. If you get rid of the backplate, maybe you can move the wing down a few inches. *I went back and read your first post again -- al. 80's are usually light at the bottom. Let's see how the trim works out and whether you're foot heavy or not.

Andy, a few questions:

DevonDiver:

The profile adapter is a bitch to fit snuggly (especially at the top)..some extra strapping made it sweeeet.

Click to expand...

I can't tell from the pictures - how did you attach the top of the Profile to your rig. It looks nicely streamlined, just curious how you did it.

DevonDiver:

Bungees (as pictured) were way too long... shortened considerably now.

Click to expand...

You are right - those were some seriously lo-o-o-ng bungees. Is there a reason you chose to attach them to the middle D-rings on the back of the Profile, rather than the top D rings?

Did you do anything to link / attach the bottoms of the wing lobes to the waiststrap, or to the plate? With a 32lb wing it probably isn't an issue, but I find that larger wings (e.g. a 51lb Rec Wing) tend to taco a bit with the Profile.

How are you clipping your tank necks to the rig? And, when you are kitted up in the water, where do the tank valves end up (how high)? I ask because your chest strap D-rings appear to be lower than I would expect to be optimal, but that may simply be a matter of perspective in the pictures.

You post is a great example of why SM is so appealing - it is a DIY'ers playground! Thanks for sharing the pics.

billgraham:

What I see is that there's too much bouyancy too high up on the rig. Backmount wings are generally designed to keep a diver in a heads up position on the surface.

Click to expand...

The top of the bladder is quite restricted by the 'protective flap' of the OMS Adapter. That solves the problem to a greater extent. 2x trim weights on the shoulders polishes it. I put trim weights on the Hollis also.. Trim is fine. I prefer the trim in this, than I did in the Hollis.

billgraham:

Let's see how the trim works out and whether you're foot heavy or not.

Click to expand...

My camera battery died and needs replacing, otherwise I'd have posted some pictures. I've been sitting on a tech wreck course all week, running the SM through it's paces. No issues at all... Had a nice dive this morning, running line through the crew quarters of an LST at 34m. Trim was definitely sorted, or I would have noticed the impacts...

Colliam7:

Andy, a few questions: I can't tell from the pictures - how did you attach the top of the Profile to your rig.

Click to expand...

Pictures to follow. I did some tweaking this morning and took some snaps on my phone to show how it goes together.

Colliam7:

Is there a reason you chose to attach them to the middle D-rings on the back of the Profile, rather than the top D rings?

Click to expand...

Habit. I'll try different approaches at a later date. That's how I had the Hollis rigged... and I started with what I am more familiar with.

Colliam7:

Did you do anything to link / attach the bottoms of the wing lobes to the waiststrap, or to the plate? With a 32lb wing it probably isn't an issue, but I find that larger wings (e.g. a 51lb Rec Wing) tend to taco a bit with the Profile.

Click to expand...

Not needed... the Profile Adapter is meant for doubles wings... so it does a very good job of holding a single wing in position.

Colliam7:

How are you clipping your tank necks to the rig? And, when you are kitted up in the water, where do the tank valves end up (how high)? I ask because your chest strap D-rings appear to be lower than I would expect to be optimal, but that may simply be a matter of perspective in the pictures.

Click to expand...

I thread the bungee all the way around the neck... not just around the handle. I get into some weird orientations sometimes when inside a wreck...

They're properly adjusted... I have big shoulders, I guess...and, yes, perspective of the pictures. Will upload some pics of the rig being worn later.

You post is a great example of why SM is so appealing - it is a DIY'ers playground! Thanks for sharing the pics.[/QUOTE]