Adding butt dump valve to Halcyon Contour?

[kafkaland]

I have two sidemount harnesses, a Halcyon Contour for cold water dry suit steel tank dives, and a Razor for wet suit Al tank kinda dives. What frustrates me a bit with the Halcyon is that it isn't as easy to dump air from the wing. I always feel like I have to break trim somewhat to use the shoulder dump, and it seems that I'm still having some air trapped in there somewhere. And my left shoulder feels already a bit cluttered, not the best place to search for the pull of the dump,valve in a hurry.

So I'm wondering if it is feasible to add a butt dump valve to that wing, and, if I go that route, where I can get such a modification done. I'm not sure my LDS can handle this competently - would Halcyon do It? Or, do you have any other advice?

 

[TotDoc]

I thought the lack of the butt dump would bother me on the halcyon, since the butt dump has long been my favorite way to vent wing gas in back mount - but so far, it really hasn't been an issue. In flat trim, I've found that rolling my shoulders a little to the right works just about as well as turning heads up a bit for dumping from the shoulder valve. By varying my elbow position as I pull the toggle, I find I'm able to also vent gas from my dry suit, or not, as needed.

If I'm in a head down position, I've found that depressing the deflator button works to dump gas, and essentially works like the butt dump would, since the corrugated hose is already situated in the rough area the butt dump would go. If you need to get every drop of air out of the wing, this wouldn't work great - but for an adjustment in a pinch, it works alright. The position of the corrugated hose is not optimum for dumping gas if you don't have a bit in the wing, but if you're only using your halcyon for cold water diving with steels, you would probably be alright. That said, the times I find myself forced into a heads down position where I need to dump wing gas doesn't seem to happen that often. Usually if I am pointing heads down, I am descending, and physics takes care of things for me.

If I'm ascending or crawling up out of a hole while cave diving, though, I really appreciate the shoulder dump.

 

[tbone1004]

I can honestly say I don't miss a rear dump in sidemount. Yes you have to break trim a little to get all of the air out, but it isn't a problem in the real world. You have to break trim in the other direction to dump from a wing or a butt dump. Obviously slightly head down is a bit more ideal than head up, but for dumping gas, it's not like you're staying there for a long time and you only have to break by about 5* for it to go.

Your LDS will most definitely not be able to do that work. You need a punch to punch the bladder and the wing cover, and then the flanges and what not to install the new dump. The flange bit is DIY and the punch bit is as well if you're feeling ballsy, but the risk of hitting the other side of the bladder is quite high. I would be very surprised if Halcyon would do that work for you.