Found a used Sherwood magnum older model reg on ebay. Great working condition. Can anybody tell me more about this type of reg. I am just starting out in diving an trying to buy quality used affordable gear. Thanks.
Sherwood Reg
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Sherwood makes a good, dependable reg and they have been doing so for many years withe the same basic design with subtle changes in appearance through the years. You can easily find part kits all over the Internet including eBay.
You will have a difficult time finding any bad press on Sherwood regs. I have at least 5 sets of sherwood regs hanging in my basement.
You should expect to pay about $100-$150 for an older (round face) set without gauges, with octo and in working order. A little more for oval faced, and even more for the newer, newer (lol they've been around a while) regs.
You will have a difficult time finding any bad press on Sherwood regs. I have at least 5 sets of sherwood regs hanging in my basement.
You should expect to pay about $100-$150 for an older (round face) set without gauges, with octo and in working order. A little more for oval faced, and even more for the newer, newer (lol they've been around a while) regs.
elan
Contributor
I'd agree. The Magnum is a generic bulletproof downstream second stage that will hold up forever. It doesn't have some of the improvements of the Oasis/Blizzard in terms of dry mouth reduction, but it's pretty tough. The first stage design, unique to Sherwood, demands a Sherwood rep who won't plug up the bleed valve with Christolube or silicone, but most shops know this by now. And of course, you'll have to explain repeatedly that the air bubbles are supposed to be coming from the 1st stage when you dive.
But let me hijack the thread over this comment:
Having just finished the Sherwood factory seminar, I can report (though the info's probably out there already) that the SR1 problems were traced to the winged poppet. For those not familiar with the SR1's persistent bad press, there was a small but persistent incidence of freeflow below ~80 feet in colder water that disappeared at the surface. There was a PR problem until the company discovered the issues, because denial was the initial order of the day.
The poppet is clearly a copycat design from the S-wing poppet that Scubapro has in the G250, except that Sherwood doesn't (yet) use the second wiper o-ring in the second groove on the poppet shaft (even though the groove is there). Maybe that'll change in the SR2. Anyway, the freeflow issue was traced to two things: a casting flaw in the poppet itself, and (maybe) slight rotation/cocking of the poppet when the adjustment knob was screwed in.
Casting flaw: When the poppet is cast from plastic, the mold is in two halves which separate. For cost reasons, the poppets were used straight from the mold. It was discovered that there was a very tiny ridge where the mold halves met, and when the tiny 2mm poppet o-ring would stiffen up under pressure and decreased temperature the balance chamber would begin to leak. The free flows were never huge, and it took a while to trace the leak to the shaft of the poppet. The solution was to smooth the poppet's o-ring grooves after they come from the mold to eliminate the ridge in the o-ring groove. That has taken care of the problem.
Poppet cocking: When you screw in the adjustment knob, you can occasionally put some slight torque on the poppet spring if there's excessive friction between the knob adjuster body and the balance chamber. If the spring catches on the balance chamber as it tries to rotate due to friction with the adjuster body, then the other end of the spring tries to torque the poppet, and occasionally it will not seal as well as it did before you "adjusted" it. Sherwood is trialing a stainless ring that will go between the spring and the balance chamber (I think) to eliminate that snagging point. That too will probably be introduced with the SR2.
Bottom line, the Sherwood SR1 second stage has a generally proven design similar to the Scubapro G250, with fantastic reduction in expiratory effort that helps total work of breathing. Their goal was to produce a WOB loop better than anybody else's on the market, and they did that. Unfortunately there were some flies in the ointment.
On the other hand, the Sherwood SR1 first stage is a work of art! I don't know if it will stand the test of time, but the engineering is fascinating! It's a piston reg, but a piston that's environmentally sealed without filling the environmental chamber with grease. The piston bore is HUGE, and air flow is amazing. I bought one off EBay just to experiment with after finishing the factory seminar. The piston is in two parts (the shaft screws into the base) and is overbalanced just a tad (the shaft is narrower than the orifice mating diameter). The mating surface with the orifice is rounded and conical, so lockup is very crisp while seat longevity ought to be excellent compared with the knife edges. But it's the environmentally sealed depth compensation that is just magical. Like a very old regulator design whose name skips my mind, increasing ambient pressure is transmitted via rods in the body of the regulator, and they now exert their force on the piston base. The sensing element for ambient pressure is a rubber diaphragm that seals against the pressure plate that pushes on the rods that push on the piston base at the other end of the reg. It's like combining a diaphragm with a piston!
You can check the depth functioning of the reg by just pushing on the diaphragm - when you do, an attached IP gauge will go up. I have a few concerns, like the thin polymer legs that transmit the force to the piston, but that's only a problem of handling for the technician who might break them off. As far as function goes, it has both things a piston guy likes in their imaginary best regulator: huge airflow and dry environmental sealing like a diaphragm.
Sherwood still struggles with their press, and I'm not as happy with build quality as I could be. But from a design standpoint, they hit this one out of the park. They caught a bad break on the poppet thing, and it came for the usual reasons: penny pinching. But I'm hoping the SR2 redeems them. Or maybe the SR3, when they're forced to convert to metal legs for the link to the piston after the techs break off all the polymer ones. If the two piece piston isn't screwed up by the LDS's, then they might do well. Then again, rumor can kill anything. Just look at Poseidon and the upstream valve myth.
But let me hijack the thread over this comment:
Having just finished the Sherwood factory seminar, I can report (though the info's probably out there already) that the SR1 problems were traced to the winged poppet. For those not familiar with the SR1's persistent bad press, there was a small but persistent incidence of freeflow below ~80 feet in colder water that disappeared at the surface. There was a PR problem until the company discovered the issues, because denial was the initial order of the day.
The poppet is clearly a copycat design from the S-wing poppet that Scubapro has in the G250, except that Sherwood doesn't (yet) use the second wiper o-ring in the second groove on the poppet shaft (even though the groove is there). Maybe that'll change in the SR2. Anyway, the freeflow issue was traced to two things: a casting flaw in the poppet itself, and (maybe) slight rotation/cocking of the poppet when the adjustment knob was screwed in.
Casting flaw: When the poppet is cast from plastic, the mold is in two halves which separate. For cost reasons, the poppets were used straight from the mold. It was discovered that there was a very tiny ridge where the mold halves met, and when the tiny 2mm poppet o-ring would stiffen up under pressure and decreased temperature the balance chamber would begin to leak. The free flows were never huge, and it took a while to trace the leak to the shaft of the poppet. The solution was to smooth the poppet's o-ring grooves after they come from the mold to eliminate the ridge in the o-ring groove. That has taken care of the problem.
Poppet cocking: When you screw in the adjustment knob, you can occasionally put some slight torque on the poppet spring if there's excessive friction between the knob adjuster body and the balance chamber. If the spring catches on the balance chamber as it tries to rotate due to friction with the adjuster body, then the other end of the spring tries to torque the poppet, and occasionally it will not seal as well as it did before you "adjusted" it. Sherwood is trialing a stainless ring that will go between the spring and the balance chamber (I think) to eliminate that snagging point. That too will probably be introduced with the SR2.
Bottom line, the Sherwood SR1 second stage has a generally proven design similar to the Scubapro G250, with fantastic reduction in expiratory effort that helps total work of breathing. Their goal was to produce a WOB loop better than anybody else's on the market, and they did that. Unfortunately there were some flies in the ointment.
On the other hand, the Sherwood SR1 first stage is a work of art! I don't know if it will stand the test of time, but the engineering is fascinating! It's a piston reg, but a piston that's environmentally sealed without filling the environmental chamber with grease. The piston bore is HUGE, and air flow is amazing. I bought one off EBay just to experiment with after finishing the factory seminar. The piston is in two parts (the shaft screws into the base) and is overbalanced just a tad (the shaft is narrower than the orifice mating diameter). The mating surface with the orifice is rounded and conical, so lockup is very crisp while seat longevity ought to be excellent compared with the knife edges. But it's the environmentally sealed depth compensation that is just magical. Like a very old regulator design whose name skips my mind, increasing ambient pressure is transmitted via rods in the body of the regulator, and they now exert their force on the piston base. The sensing element for ambient pressure is a rubber diaphragm that seals against the pressure plate that pushes on the rods that push on the piston base at the other end of the reg. It's like combining a diaphragm with a piston!
You can check the depth functioning of the reg by just pushing on the diaphragm - when you do, an attached IP gauge will go up. I have a few concerns, like the thin polymer legs that transmit the force to the piston, but that's only a problem of handling for the technician who might break them off. As far as function goes, it has both things a piston guy likes in their imaginary best regulator: huge airflow and dry environmental sealing like a diaphragm.
Sherwood still struggles with their press, and I'm not as happy with build quality as I could be. But from a design standpoint, they hit this one out of the park. They caught a bad break on the poppet thing, and it came for the usual reasons: penny pinching. But I'm hoping the SR2 redeems them. Or maybe the SR3, when they're forced to convert to metal legs for the link to the piston after the techs break off all the polymer ones. If the two piece piston isn't screwed up by the LDS's, then they might do well. Then again, rumor can kill anything. Just look at Poseidon and the upstream valve myth.
Parts including pistons and 2nd stage bodys are or soon will be non existant for the older Sherwood regs. fyi.
gtboomer
Registered
Thanks rsingler, that is the first ever explanation for the SR1 issues. All I got from the Canadian factory rep was BS, including "You must have dropped it". (This was not a free flow issue but a problem converting them from yoke to DIN) Quality control issues on the thread size.
Thanks again for the info.
Thanks again for the info.
reefrat
Contributor
The latest version of the magnum (also blizzard/ oasis) is good too, I used one for 10 dives and was quite impressed with the overall performance. My only reservations were the non-user removeable front on the second stage (not a biggie) and the fiddly schraeder valve reliant first stage. Neither of these points were deal breakers individually but combined tipped me in favor of walking away.
Now a new magnum second stage combined with the new SR3 piston first stage would be a robust unit and high performance!
Now a new magnum second stage combined with the new SR3 piston first stage would be a robust unit and high performance!
A bit late to the thread but the older piston 1st stage with the 3 transfer pins was a Cressi Sub.
ams511
Contributor
Could you be a bit more specific? I thought the first stages were pretty similar from a parts standpoint.
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