Tips for backmounting an AL19 pony?

[afieldofblue]

Slingshot mount is the best imo. The base stays attached to your can band and the mount is attached to your pony. You can swap tanks without having to change your mount system over to the new tank or having a 2nd/3rd base for the system to use on different tanks. I mount mine upside down so I can manipulate the valve if every needed. I also put a hose keeper at the mount to run the 36" hose up the tank and then under my right arm. The reg is then clipped to my right shoulder d-ring. This keeps it tight and I can pull the hose to release it when needed.

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On this design, how stable is the mount's single attachment point?
I'm trying to understand why the Shark design has a rigid bar linking to the valve for a dual connection point whereas Quickdraw style mounts have a single one. No wobblies?
Has anyone tried both Shark and Quickdraw mounts?

Slider-type attachement mounts cover a longer surface area, so I can see how that would work to stabilise the rig, but less sure how it works for the Quickdraw's single connection point.

thanks!

 

[johndiver999]

Possibly another point to consider, what depth is the OP intending to dive?

If it is relatively shallow like 60 feet or something, a case could be made that a 6 cuft pony will be enough to get to the surface (if no safety stop is required in an emergency). The variability in primary tank length and potential conflict with the cam band(s) from the BC can become an issue, especially with really short (primary) tanks. So if a 6 (versus a 19) could be justified, the back mounting options might become easier, since a tiny tank should be able to fit with a single attachment placed almost anywhere and stability of the mount becomes much less of an issue.

Don't want to take it off topic and tell you to sling the bottle, like some others have done.

 

[1fspeed]

As a follow-up question, how height adjustable is the Shark bracket? I've been looking at the pics and it's a little difficult to understand what flexibility the metal rod connected to the tank valve offers in terms of primary tank height/design.
Thanks

Here a video showing what I'd do a poor job of communicating in multiple paragraphs

 

[johndiver999]

Here a video showing what I'd do a poor job of communicating in multiple paragraphs

That looks terrible! You have to bend down and work that strap closed at the bottom of the tank on a rocking boat? LOL. The guy could barely do it when the tank was elevated on a table!

 

[Boarderguy]

On this design, how stable is the mount's single attachment point?
I'm trying to understand why the Shark design has a rigid bar linking to the valve for a dual connection point whereas Quickdraw style mounts have a single one. No wobblies?
Has anyone tried both Shark and Quickdraw mounts?

Slider-type attachement mounts cover a longer surface area, so I can see how that would work to stabilise the rig, but less sure how it works for the Quickdraw's single connection point.

thanks!

It's rock solid! I don't go in the water without my pony regardless of dive plan. Even on doubles I still sling a 40. The spare tank is my best friend and more loyal than my wife.

There is zero movement felt or imagined with the quick draw system. The pins are quite solid and a near perfect fit. I can get the tank to jostle a little bit by hand but it doesn't equate to movement in the water or when walking.

 

[Nemrod]

The spare tank is my best friend and more loyal than my wife.

I have seen people use an old STA. Cut a second set of slots, mount it to the tank cambands and then the mini-cambands (or adjustable screw clamps covered then with 20-23mm racing bicycle tube) through the newly cut slots for the pony.

My ID doubles still has a 30cf pony mounted using an old STA. But I mostly sling now, easier for me usually.

 

[grantmac]

With correctly side mounted tanks I can touch my dpv D ring or drysuit inflator to the bottom before any other piece of gear makes contact.

My experience with diving in Japan is that the skill level was very low and equipment was poorly managed. So I have no doubt the OP simply hasn't seen things done very well.

 

[afieldofblue]

Here a video showing what I'd do a poor job of communicating in multiple paragraphs

Thanks - I'd seen it but on watching again more closely it might be a little problematic as the all the clamps seem to be welded on the pole in a set position, which might make height adjustment difficult, especially if I ever need to a accomodate a shorter tank like the 10L steels they have here.

I got here a few months ago in winter still figuring out the rental tank options here.
It's a little strange because it's mixed steel/aluminium because of the temperature range, and due to body size/air consumption Japanese divers prefer shorter tanks.

I have no issues with steel, especially if I'm still diving dry like I am now, but the longer tanks are 12L steels, and but not all filling stations have them.
That said, given that it's also warm water half the year, there are aluminium tanks as well, AL80s or local alu equivalent.
The Shark system, with its set attachment points, might be off the list because of this question of variability of tank sizes.
I'll probably get my own tanks in the future, but because of local complications and the fact that I live in an appartment and not a house will be a progressive and calculated endeavour.

Okinawa's a strange place, because there is also a parallel circuit of military SOFA personel stationed here, with their own on-base dive shops (Tsunami Scuba), filling stations, which don't need to comply with national Japanese regulations (like KHK certificatiosn for tanks), but I don't have access to this and am on the local Japanese circuit when it comes to equipment sales, tanks and fills.

 

[afieldofblue]

It's rock solid! I don't go in the water without my pony regardless of dive plan. Even on doubles I still sling a 40. The spare tank is my best friend and more loyal than my wife.

There is zero movement felt or imagined with the quick draw system. The pins are quite solid and a near perfect fit. I can get the tank to jostle a little bit by hand but it doesn't equate to movement in the water or when walking.

Thanks for that - this might be a nice option on an independent cam band, more flexible than something like the Shark with its set attachments. Might be a little tricky to get sent over here (most sellers I found where in the United States and shipping in the CONUS only), but it seems like a solid (pun intended) option with my setup.

 

[afieldofblue]

I have seen people use an old STA. Cut a second set of slots, mount it to the tank cambands and then the mini-cambands (or adjustable screw clamps covered then with 20-23mm racing bicycle tube) through the newly cut slots for the pony.

My ID doubles still has a 30cf pony mounted using an old STA. But I mostly sling now, easier for me usually.

Yes, I think this is the solution I had on the rig a used a few years back, for a backmounted steel pony, or maybe it was the slider-type solution others have mentioned.
My memory is a little blurry, as I only used it a few times but liked it. DIY / refurbished is certainly possible for this, I just need to find something that can work well with my gear.

On the steel/aluminium sissue, given how impossible it is to find smaller KHK certified smaller tanks, I'm grateful to have found this KHK re-certified Luxfer AL19, which is a really unicorn, allowing me to get fills in standard Japanese stations.
As I mentioned above, most people with non-standard tanks I've talked to here (people with rebreather cylinders, bailouts and stages) just use transfill whips and give up on hydros.
Which is fine, but quite illegal as well, and could cause issues.

I looked at the process to get a DOT cylinder KHK re-certified for legal use in Japan, and it's a lot of work, time and money...
anyway, thanks again