Tuning Hw90 pressure accessories

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Mycapt65 said:
OK sorry that happened. Mine was a 2000 RX1. I remembering lubing the oring so it didn't get cut. I think it may have have been an odd metric size or something. My bet is the gun is the same but RS changed orings. Weihrauch almost never changes anything. I'm trying to remember more.
At least the pump is working out for you.
Be well
Ron
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No worries! I am still in it for less than any of the other options. I needed a shock pump for my kids' bikes so I would have bought a shock pump regardless! I wonder if your RS adapter is physically different. I think if the adapter would have had the threads cut all the way to the shoulder of that non-threaded step, it would have worked. Thanks for pioneering the original alternative!
 
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Grandmastah said:
I did consider it would dump all the air so when I tried it the first time, I attached the adapter to the pump first and spun the pump to thread the adapter in. I did try pumping to see if it would do anything but it would not build any pressure, but I only gave it a few strokes... I will give it another try. I assumed the adapter would depress the valve and you would be able to use the shock pump gauge to determine the pressure.

I assume this means that the only way to estimate the pressure is to release all the air so you know you are at 0, and then build it back up with the shock pump and assume maybe you are a 1/2 to 1 bar less than the shock pump indicates from the slight loss when disconnecting?
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you can always pump up until you hear it going in.. plus the gauge on the pump should climb slower when you reach ram pressure, just like PCP guns the pressure goes up fast when you are just filling the line and then goes slower when filling the additional reservoir.
Mark
 
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markhooper said:
so this thread mentions a shock pump and someone else said that they used it for bikes.. I did see that it said 26 bar.. what's the psi conversion for 26 bar.. I know that I put 250 bar in my PCP, but I would have thought that it would be more than a bike pump would be capable of for the gas ram..
Mark
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Roughly 15 psi per bar. The gas ram in question is a Theoben designed air piston. It's different from the popular gas ram models. The theoben piston in the guns discussed has an advertised maximum pressure of 24 or 26 depending on the model year. There's really no need for more than 26 bar, so the bike shock pump is fine. Most people find these guns shoot best between 18 and 21 bar. I liked mine around 20-22 bar.
 
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Mycapt65 said:
Roughly 15 psi per bar. The gas ram in question is a Theoben designed air piston. It's different from the popular gas ram models. The theoben piston in the guns discussed has an advertised maximum pressure of 24 or 26 depending on the model year. There's really no need for more than 26 bar, so the bike shock pump is fine. Most people find these guns shoot best between 18 and 21 bar. I liked mine around 20-22 bar.
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a bike shock pump must be different than a tire pump because I just multiply your numbers and got 390 PSI.. so it must be a higher pressure for like a actual shock absorber?
Mark
 
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Hope this helps any members
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FOR ANYONE STILL WONDERING ABOUT ADJUSTING HW90 POWER=I use the ROCKSHOX 600 PSI pump Schrader adapter with teflon tape to pump up my HW90/.25. Works great, adapter cost 9 bucks:
Rockshox Monarch Air Valve Adaptor Tool

Rockshox Monarch Air Valve Adaptor Tool | Jenson USA

www.jensonusa.com www.jensonusa.com
Use small metal rod to tap out pressure. For this unit, using either old DIANA MAGNUM 20grain or H&N FTT 20.06grain, i get 19.0FPE from factory setting with 60LBS cocking effort, ~18.51 FPE=20BAR with easy 40LBS cocking effort; 12.5FPE=14/15BAR with very easy cocking. BAR measurements using Rockshox High Pressure Fork & Shock Pump-

Rockshox High Pressure Fork & Shock Pump | Jenson USA

www.jensonusa.com www.jensonusa.com
Cocking force measured with bathroom spring scale. The brass AOA Quick connect male to Schrader valve only works if I take off stock, because our Benjamin hand pump's female head is to big, causing interference with stock.
 
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FWIW-From hw90 homework and experience with my .25 HW90 unit, I expect 20BAR is starting point for finding max power and accuracy with lowest standard deviation. I expect to find that before I get down to 18BAR. Then i'll work up best lowest power setting for indoor practice.
Using open sights with "open" peep front insert [to let in max light]. Will try full peep sight insert just for fun, after I find best pellet and power. going from 12 foot 1/4th inch bullseye, to 33foot 1/4 inch bull. Starting, with old [for springers not pcp's] Diana Magnum .25, 19.90grian, .249" heads sorted, .256 to .257" skirts. Diana's seem softer alloy then H&N FTT's 20.06 [minimum factory spec of 18fpe], and skirts generally mic bigger. Diana's consistantly chrony faster then H&N FTT, ~7 to 11fps.
 
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