Tuning Hw90 pressure accessories
- Thread starter rapstarD
- Start date
The one thing nice about the Weihrauch gage is that it allows you to progressively reduce the pressure. Each time you press it inward against the schrader the pressure drops about 0.2b. I only have two HW90, the first came in at 26b as received. The second rifle came at a lower pressure, about 22b, if I recall.
I've found I prefer the rifles in the 20-22b range.
I've found I prefer the rifles in the 20-22b range.
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Did you get a chance to try to the shock pump and adapter? I recently picked up a HW90 and bought the shock pump and adapter, but the adapter did not work for mine. The adapter does not appear to be long enough to engage the valve. This is the adapter i picked up:
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It is. It will work. I was the one that figured out the pump adapter combination in the first place. I initially removed the stock and found the adapter was just long enough with the stock on. You're welcome.
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I have not tried it yet. I could not fund an adapter for sale here in canada. My local bike shop could not place new orders until 2024. Ill be following up to order one. Did you try pushing it in while rotate?
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I threaded the adapter in as far as it would go. I then tried again with the o-ring on the end of the adapter removed. The adapter bottoms out but does not depress the stem in there enough. Once it is screwed in you cannot press/push it any further.
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There is not any interference with the adapter and stock. The adapter will thread all the way in, it just does not depress the valve.
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Interesting. How old is your hw90? Is there any chance older vs newer production are different?
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The adapter isn't supposed to depress the valve. Otherwise it would dump all the pressure. When the pressure from the pump gets higher than the other side of the valve, it forces the valve open. When you disconnect the pump from the adaptor it will burp some pressure and the valve will close again. If you want to drop the pressure you tap on the valve with a small punch. Go easy on it. It doesn't take much to drop the pressure considerably.
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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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With the Weihrauch gage, you get a drop of about 0.5b every time you take a measurement. Sooo, I would guess if you just tap the schrader you would get a similar drop. Not a satisfyingly accurate method but worth a try?
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There should be a S load of pressure in the air piston. You'll have to pump the pump several times to overcome the sitting pressure. IIRC you have to get at least a half bar more pressure on the pump side to overcome that static pressure and break the valve open.
FWIW the actual pressure number is irrelevant. You'll lose pressure every time you disconnect the pump. All you need to do is record the pressure you disconnected the pump at and note the results. What the actual number in the piston doesn't matter as long as you have a steadfast method.
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I was not able to get the shock adapter to work for my HW90. My HW90 is a newer one, received it from AOA about a month ago. The threads on the adapter were correct pitch and would thread in ok, but it would not seal. I tried a few different o-rings to try to get it to seal off but it just would not work. I found this:
www.pyramydair.com
They do not show a picture of it on the website but this is what you get:
It has the theoben shrader on one side and an 1/8" BSPP on the other end. I got these:
shrader valves on Amazon so that I could use the rock shock shock pump. Also I did not previously see this, so I think it is new to AOA, but they have an adapter now to:
But it has a QD on the end which would have required more adapters to get me to a standard shrader valve to use with the shock pump. I wish the shock adapter would have worked for me but I was not so lucky. Just adding my experiences to the thread in case anyone else has the same issue with the shock adapter.
Beeman Filling Hose, RX-2 & HW90 | Pyramyd AIR
We've got a great price on Beeman Filling Hose, RX-2 & HW90 at Pyramyd AIR. Shop where the experts do!
www.pyramydair.com They do not show a picture of it on the website but this is what you get:
It has the theoben shrader on one side and an 1/8" BSPP on the other end. I got these:
shrader valves on Amazon so that I could use the rock shock shock pump. Also I did not previously see this, so I think it is new to AOA, but they have an adapter now to:
But it has a QD on the end which would have required more adapters to get me to a standard shrader valve to use with the shock pump. I wish the shock adapter would have worked for me but I was not so lucky. Just adding my experiences to the thread in case anyone else has the same issue with the shock adapter.
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Does the new hose fit your shock pumpI was not able to get the shock adapter to work for my HW90. My HW90 is a newer one, received it from AOA about a month ago. The threads on the adapter were correct pitch and would thread in ok, but it would not seal. I tried a few different o-rings to try to get it to seal off but it just would not work. I found this:
Beeman Filling Hose, RX-2 & HW90 | Pyramyd AIR
We've got a great price on Beeman Filling Hose, RX-2 & HW90 at Pyramyd AIR. Shop where the experts do!
They do not show a picture of it on the website but this is what you get:
View attachment 430443
It has the theoben shrader on one side and an 1/8" BSPP on the other end. I got these:
shrader valves on Amazon so that I could use the rock shock shock pump. Also I did not previously see this, so I think it is new to AOA, but they have an adapter now to:
But it has a QD on the end which would have required more adapters to get me to a standard shrader valve to use with the shock pump. I wish the shock adapter would have worked for me but I was not so lucky. Just adding my experiences to the thread in case anyone else has the same issue with the shock adapter.
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Yes that is the adapter I used. Here is a pic of the adapter next to fitting on the hose.
The hose fitting is a little longer and has a more pronounced shoulder. With the shock adapter I tried the o-ring that it came with it, a larger o-ring, and an o-ring that fit up on the step of that adapter as well trying to find the combination that would work. No combination would seal. It would almost seal. Pumping the pump, it would temporarily get up to 5 or 6 bar by the end of the stroke, but would leak off by the time you started the next stroke.
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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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