Which is better for pumping?

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hatssold
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Sun Apr 26, 2009 1:06 pm

Which is better for pumping......

A Bike Pump
or
A shock pump?
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Moonbogg
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Sun Apr 26, 2009 1:15 pm

Oh a bike pump totally. A shock pump would take forever depending on how big the chamber is. I will give you a direct example. Look at the cannon in my sig...It takes about 15 full stroke pumps with a full sized bike pump to fill the chamber to 15psi. A shock pump would probably take all day.
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POLAND_SPUD
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Sun Apr 26, 2009 1:25 pm

hmmm... don't take the above post seriously ;-)

it's all about scale - for small bore size (1/2" or smaller) a shock pump is ideal as it can reach much higher pressures (~400 psi)
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Big-E
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Sun Apr 26, 2009 1:43 pm

Actually, you could use both. A bicycle pump flows more, but maxes out sooner.

I have a shock pump on my gun, and with the small chamber, I can fill it to 50 PSI in 40 pumps or so. I can achieve that in about two pumps on a bicycle pump.

But, as I said, you could use both. Use the bike pump first to fill the chamber, and top off/bump up the pressure with the shock pump.

The best option would be to build a pump. Small diameter pipe for the pump body would allow for higher pressures, but increased pump volume would flow more than a shock pump.

FYI, there are dual-role stirrup pumps (bicycle pumps) that can achieve pressures as high as any shock pump, but they can be a bit pricey. still, it's a good option if you can afford one.

Here's an interesting one at this link: http://www.serfas.com/product_details.asp?ID=240
It's about the size of a frame pump (slightly fatter than a shock pump), it features a switch to change from high to low pressure pumping chores. it's like having two pumps in one. I for one would love to use this on a pneumatic, but it's almost $50. You use the low setting to fill your chamber, flip the switch to high and bump up the pressure. it even has a nice pressure gauge on it.
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Hotwired
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Sun Apr 26, 2009 2:10 pm

POLAND_SPUD wrote:hmmm... don't take the above post seriously ;-)

it's all about scale - for small bore size (1/2" or smaller) a shock pump is ideal as it can reach much higher pressures (~400 psi)
Ehhhh.... more like 6mm or smaller.

My cannon has a 1/2" bore and you'd be there HOURS pumping it up with a shock pump.

I can get it to 260psi in less than half a minute with my track pump. No it's not modded, it has a 160psi gauge but it doesn't do anything horrible when overpumped.

However some pumps will fail if you overpump them.

Track pumps are the best thing you can use if you neither have/want a compressor or bottled gas.

Hand pumps are a bugger to use for long.

This one looks the business for decently high pressure
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Biopyro
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Sun Apr 26, 2009 2:20 pm

What we need is a stirrup style pump capable of 300psi. The joe blow ace goes to 240psi and is £60. I have the sport which goes to 180psi and is very reliable, a great pump.
What do you use hotwired? I can't really get mine past 180psi without a lot of effort because I'm not heavy enough.
Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety. -Benjamin Franklin
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POLAND_SPUD
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Sun Apr 26, 2009 2:46 pm

@ hotwired well I've never had one... with a fridge compressor it takes about 20 seconds to fill 100 ccm chamber to 300 psi... so this means that my definition of small flow has to be revised

:wink:
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Hotwired
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Sun Apr 26, 2009 4:50 pm

This is mine:

Clicketh

42mm cylinder and I'm about 70kg. Maybe it's 40mm after taking off the thickness of metal.
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covey12
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Sun Apr 26, 2009 5:13 pm

if you go to either remington or crosman bb gun websites, they sell a bicycle type pump that reaches 2500psi for there pcp gun, it works extremely well
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mark.f
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Mon Apr 27, 2009 9:11 am

That pump is also extremely low flow. The Crosman model takes about 100 pumps to bring the PCP reservoir on their Discovery to pressure (2.5 kPSI), which is simply a small diameter pipe running under the barrel.

Personally, I just buy the cheapest bike pump I can get my hands on that has a metal barrel. I've taken cannons up to 300 PSIG with the cheap Husky pumps they used to sell at Home Depot, but you have to be slow and careful about overheating or they'll melt seals and lock up.
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