What 2nd has beat the G250?

[rsingler]

Back from BVI, great trip! The 17E2 performed beautifully, and it'll definitely be my travel first stage of choice. I won't lie, I didn't fall in love with the S620Ti, though. It was noisy at depth...enough to annoy me.

I swapped to the G260 halfway through the trip, and it was a dream. Same silky performance as the ole G250, which I let my son dive. He asked if he could keep it. LOL.

It's amazing how often the old G250 comes up in discussion regarding its smooth performance, despite being more than 40 years old!
I think it's time for another bruising debate about the best second stage! But to avoid (okay, minimize) the thread hijacks, I'll restrict my comments at least, to the barrel design, end-balanced regs that mimic and maybe improve upon the G250. No center-balanced D400/TFX gushing here!

G250 Pro's:
* Smooth!
* Tunable so that Venturi kicks in just the right amount with heavy breathing to reduce effort to near zero.
* Indestructible case
* Barrel locked in position with a square broach in the case so that the lever can't be twisted out of vertical (Apeks? Hello?)
* Metal barrel which may improve dry mouth or aid against freezups (urban myth?)

G250 Con's:
* NO MICROADJUST! Your minimum cracking effort may be too stiff with the knob fully out; your min cracking effort may be too low, wasting much knob travel just to prevent freeflow
* Most everyone bent the knob shaft reinstalling the barrel retention C-clip
* Flat diaphragm, with limited lever travel at high gas density
* Metal lever feet eventually wear a notch in the metal barrel, making lever action "clicky" after forty years
* Exhaust valve is "okay" with average exhalation WOB compared to "the latest and greatest".

 

[rsingler]

So what's "Better"?

G260 -
Pro's: Microadjust! Taller diaphragm w/ better lever excursion
Con's: Actually a shade mouth heavy; exhalation valve unimproved

S620Ti -
Pro's: Has a plastic guard on the metal barrel to protect the lever from wearing it; tall diaphragm; improved exhaust
Con's: Case won't likely last 40 years; the microadjust sucks (it binds between service)

C370 -
Pro's: Huge Venturi assist! Improved exhaust; beautiful lever with large excursion and low friction; HUGE gas flow!
Con's: plastic barrel

 

[rhwestfall]

Re: c370

...you can replace the plastic c370 barrel (likely less cost that the other models metal barrels) with another and get more years..

 

[rsingler]

How about other brands?

Apeks XTX50 -
Pro's: microadjust
Con's: everything else. Lousy barrel retention - easy to twist out of vertical. Flimsy case. Poor purge valve excursion. Average flows/venturi augmentation on testing, as the whole competing Venturi design has no vane at all, but instead just a disrupter roof over the gas exit hole

Apeks EVX (new) -
Pro's: microadjust, metal barrel (mostly); poppet spring moved out of gas pathway!!! I don't know much more - only disassembled one at DEMA; never dove it
Con's: only marginally improved barrel stabilization bosses - clearly inferior to SP; lots of internal plastic bits

Mares Epic -
Pro's: Aux gas pathway adjacent to valve orifice virtually eliminates lever freezing; new barrel design eliminates the need to bend the lever legs for removal during service; above average gas flow
Con's: A shade mouth heavy; average Venturi augmentation at high gas flow; no improved exhaust WOB over older designs; barrel retention controlled by a single thin plastic clip.

Sherwood SR2 -
Pro's: external control to tune orifice without removing hose; tall lever with good excursion
Con's: lots of plastic internal fiddly bits; average Venturi augmentation

Cressi -
Thin plastic everything! Someone correct me.

 

[rsingler]

Let the battle begin!

 

[rsingler]

Re: c370

...you can replace the plastic c370 barrel (likely less cost that the other models metal barrels) with another and get more years..

Yeah, I have to admit @rhwestfall , I think the C370 is the best thing to come along since the G250. If only they hadn't moved the poppet spring back in the way, instead of the magnificent C350 (unbalanced). Apeks EVX took their idea and ran with it, though everything else is meh.

C370 is lightweight and the gas flow is magnificent for deep dives, though the Venturi needs a hair of throttling back, which is easily done on the fly.

And that metal A700 sleeve inside the C370 adjuster knob rusts and freezes up with poor rinsing. That definitely won't last 40 years. It's one time I'm wishing for plastic, lol! Or titanium! That would be a huge improvement.

But I'm open to a better suggestion!

 

[runsongas]

i own a g250 and a pair of s550, i pretty much never dive them. i use my apeks or apeks style regs pretty much exclusively, the performance is plenty and i haven't had any issues with them breaking either other than hog seats wearing out a little early.

i fail to see how the g250 is any more rugged and the barrel twisting/weaker venturi are negligible issues. the popularity of apeks and apeks style regs on the market pretty much speaks to that it isn't a concern for the majority of divers.

you might as well be arguing the tiger is a better tank than the sherman but guess what the sherman still won the war even with its flaws

 

[Pressurehead]

My view of 'what's better?' Is limited as my stable of regulators [that I still dive] is an unknown number of G250 [2 from Couv the best of the bunch], 1 G250v [I acquired from Simon] and 2 G260.
The G250v and the 2 G260 are my "go to 2nd stages".
So for me, my search is over, the above do everything I want or need in a 2nd stage.

Oh, not forgetting the S600, another sweet breather that comes along sometimes [thanks for the reminder, it needs a service].

I will follow this topic though , the search sounds interesting. Edit usually typos.

 

[BoltSnap]

1. B2 Atomic Second Stage with AFC

2. S620Ti

3. S600 (very close to the S620Ti)

4. C370

5. G260


All above based on extensive use. The S620Ti I used over several dives wasn't mine but the rest are all mine. I had a tank with a MK25 first and all of these seconds connected it to it down to 25 - 30 meters switching between second stages. I was swimming around dragging this tank on my side. I still had my main tank on my back with Atomic ST1 regulator. All second stages were tuned to lowest cracking pressure allowed by the mfg. which was about the same for all.

In reality, they were very close to each other. The difference was subtle and subjective sometimes. The Atomic was the most smooth in breathing.

 

[BoltSnap]

S620Ti

-Con's: Case won't likely last 40 years; the microadjust sucks (it binds between service)

And that metal A700 sleeve inside the C370 adjuster knob rusts and freezes up with poor rinsing. That definitely won't last 40 years. It's one time I'm wishing for plastic, lol! Or titanium! That would be a huge improvement

I don't know how you come up with these observations/opinions. The S620Ti hasn't been around to see these problems. All feedback I hear from either my students who bought it, and I borrowed from them to test, and my friends in Malta and the Red Sea who use this second stage rave about it.


As for the C370, this is the most used second stage in my training/rental regulator fleet, and there are no issues with rusting or freezing up at all, even when they may not be the most cared-for second stage I have.


I think you are just saying this as a "click/response bait" to get me to respond and get excited so I can't fall asleep after reading your post.