SM LP Inflator Hose Routing Question

[bada3003]

If I understand your question correctly, the hose routing you're considering is one of the feasible options and Lamar Hires has a youtube video that explains it. In particular, they (Dive Rite) sell an adapter called BC hose quick disconnect that facilitates over the shoulder routing (you can find it at divegearexpress including video). I dive mainly in an SMS100, drysuit in cold midwest waters. Initially I kept the inflator in the default configuration since I was diving mainly in open water and wreck penetration is modest. I got the adapter and it helps with connect/disconnect.

As a side note, I had implemented my own versions of Edd's mods except for keeping the inflator in the default left shoulder configuration. However, I ended up moving it to the left bottom for four reasons: one, with drysuit and thick gloves, the bottom dump valve had a tendency to play hide and seek, so did not get used much (not an ideal situation in horizontal trim); two, in the SMS100 with the inflator is attached to the shoulder, the hose ends up supporting some of the cylinder weight when donned on the surface (when there's a swell/current, it's more tricky to don the tanks under water in open water); this is I think SMS100 specific; three, over the shoulder hose routing, even with the special adapter, creates clutter just by virtue of the longer hose; as victorzamora mentioned getting the right hose length is not easy (have a bunch of them in the closet); four, it is more of an entanglement hazard when entering wrecks. After the switch I can use both the inflator and shoulder dump to dump air in horizontal trim, and when I inflate the BC's wing, air enters into the bottom area directly (without diffusion from the shoulder area in the default configuration) which is where it's most needed to better align center of gravity and buoyancy; the upper part of the SMS100 has been significantly constricted to induce this imbalance (one of Edd's mods) which in the SMS75 is built into the wing/BC design. Among other things.

 

[ffdiver]

I have all my sidemount rigs set up with the inflator hose coming from the bottom and have dove that way for a few years. Lately though I have been sersiously considering moving the inflator hose back over the shoulder. I have found I have more reasons to have the hose over the shoulder rather than coming from the bottom. YMMV.

 

[Mike.D]

Care to elaborate ffdiver?


Sent from my iPad using Tapatalk

 

[ffdiver]

Sure. The reason why I would want to change the LPI hose routing is for ease of venting. It's really only an issue if you are in either a heads down position or heads up.

In my armadillo and nomad exp I have to go from a horizontal position into a heads up to vent. Not that big of deal but can get annoying if you are swimming head down to get into something. there is no butt dump on either system.

Another issue I had is with the nomad lt. Venting air at the surface is a pain with the cave version since you need to get your butt up into the air to vent. its fine when you are horizontal but when you are coming up in a vertical position which happens, you can't dump air quickly enough.

Unless you are diving in some incredibly small spaces and I mean like alot. Every other weekend where you are putting tons of strain and bumping and grinding your lpi connector on the shoulder, I don't see the big deal with keeping it up there.

Ideally, having a dump on the shoulder and butt with the LPI coming from the bottom would work best.

 

[victorzamora]

......but when you are coming up in a vertical position which happens, you can't dump air quickly enough....

What's funny is this is the exact condition that talked me OUT of an over-the-shoulder LPI. I was taking my Cavern/Intro class, coming up a tight(ish) space, with one hand on the line and the other on my buddy. I didn't have the time or space to hold my LPI over my head to dump gas. Now, I move a little knob like a half inch. MUCH easier. It's also easy for descending from vertical or horizontal.

When swimming head-down into stuff, you should never have to dump gas. If you were neutral (or close), you should be more negative when you descend. Very little reason (if any) to butt-dump while descending. When you dump gas from your wing, you might also want to dump gas from your drysuit. This would happen upon overinflation or upon ascent.....not upon descent (once diving). There should be no hindrance in the real world to not having a butt-dump. The hindrance of an over-the-shoulder inflator is that dumping on ascent is harder than with an OPV (pulling knob vs lifting the lpi above your head and then activating). The other big issue is hose routing. Routing a clean hose to your LPI is MUCH easier when your inflator is routed from the bottom. The only reason people use over-the-shoulder inflators in SM is as a carryover from backmounted tanks. In BM, it makes sense to have an OTS inflator, because the hose is MUCH more cleanly routed than if it were a bottom-up inflator, like is so common in SM.

 

[shellmoundal]

If you are serious about wanting to dive sidemount correctly I would suggest a trip to Florida and get an appointment with Edd Sorenson. He designed the SMS 75 and for a good reason. In reading some of the posts I understand that some SM Divers go vertical and horizontal. Edd will teach you how to bend your body like a fish and be keep you trimmed in a up or down situation. We dive in caves that require a rise and fall continually due to the structure of the cave. By diving in a bent up position for higher elevation or a bent down position for a drop in height you are eliminating the use of the inflator and dump. Many SM Divers use their inflator for raising their position and the dump to go down. The problem with that method is every time you inflate you are using more of your gas and every time you dump you must inflate again. This sounds confusing but a 2 day SM Course with Edd in Mariana Florida will be worth all the time and money you spent.

I have 2 SMS 100's. The first one I purchased was from Edd with his modifications. I was not comfortable with it on the land but once in the water the lower inflator with the dump on the left shoulder made sense. When you are trimmed out properly the inflator across the chest is in the perfect position for memory and the dump on the left shoulder is only 3 inches from the inflator and both are controlled by the right hand. Nothing is in the way. My second SMS 100 is a double bladder system. The inflator on the left was on the bottom but the inflator on the right was on the top. The top inflator dug into my shoulder so I modified it to be on the rear and the dump on the top right shoulder. I use this system for diving wet.
After taking a class you will be able to gear up and not have all the problems with trim or buoyancy. Look at most SM Divers. They are either diving bottom mount or V diving. The tanks should be located along the side of your body and the hoses should be on the inside between the tank and your body. In this position there is no chance of rupturing a hose in a tight restriction.
Good luck with your diving. What ever works for you is best. My position is take a lesson from a real pro and then tweak what is comfortable for you. Do your tweaking after a dive with your instructor. He or she can make the call if your change is safe.

 

[tbone1004]

what is also interesting is that since I have been diving sidemount, about 5 years now, I've been using my nomad more and more with backmount doubles and actually prefer the bottom inflator to the over the shoulder in backmount provided you have a chest strap and have switched my singles wing to dive like that. I run the inflator up to the chest strap and have it tied into the left side. I use a drysuit hose and run the inflator the same way I do with a drysuit. Works very very well. Only problem is I had been using a Jim Wyatt trick with running the SPG hose down the inflator with the LPI hose and had to go back to a longer HP hose to run it back down. I find the high mounted dump works well, even in good trim, but it's the low mounted inflator hose run to the middle of the chest that just makes everything so much cleaner and easier to use.