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 Post subject: Re: 21 Gram Pump
PostPosted: Mon Mar 24, 2014 7:22 pm 
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Joined: Wed Jan 12, 2005 6:04 am
Posts: 454
Location: USA
I've been using the Topeak Micro Rocket. It weighs 55 grms. The claim is 160 PSI. When I need to use it on the road I only need about 30 PSI, and then I'm on my way home. I bore easily with the pumping process.


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 Post subject: Re: 21 Gram Pump
PostPosted: Mon Mar 24, 2014 8:10 pm 
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Joined: Mon Apr 11, 2011 6:28 pm
Posts: 180
Location: Palm Coast, Fl.
It would be interesting to see if this can get over 60-70psi. My Airstik SL can do about 70 max without some Schwarzenegger arm influence.


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 Post subject: Re: 21 Gram Pump
Posted: Mon Mar 24, 2014 8:10 pm 


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 Post subject: Re: 21 Gram Pump
PostPosted: Tue Mar 25, 2014 3:47 am 
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Joined: Mon Sep 07, 2009 3:10 am
Posts: 372
I have one on the way. Even 80-90 psi would get me home.


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 Post subject: Re: 21 Gram Pump
PostPosted: Tue Mar 25, 2014 9:28 am 
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Joined: Sun Jan 12, 2014 3:44 pm
Posts: 15
A small diameter pump will give you more pressure than a large diameter one. The number of strokes is another story.


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 Post subject: Re: 21 Gram Pump
PostPosted: Thu Mar 27, 2014 4:27 am 
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Joined: Wed Apr 11, 2012 3:40 am
Posts: 425
I'll stick to my Lezyne road drive.


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 Post subject: Re: 21 Gram Pump
PostPosted: Thu Mar 27, 2014 3:26 pm 
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Joined: Wed Jan 29, 2014 6:33 am
Posts: 42
I'll be interested to hear how these work. Can't imagine you can actually get to 150...


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 Post subject: Re: 21 Gram Pump
PostPosted: Thu Mar 27, 2014 7:37 pm 
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in the industry

Joined: Sun Sep 27, 2009 3:08 am
Posts: 88
DrGalactus wrote:
http://www.bikerumor.com/2013/12/31/kickstarter-meet-the-ipump-the-worlds-lightest-bike-pump/

$80 and only takes 100 pumps :shock:


If you have an OCD mind like mine, you'll know that any standard minimpump takes about 300 strokes to get a road tire to 120psi. This ipump is less than 1/4 the size of a standard minipump.... I'll let you do the math on the number of strokes to full inflation. (p.s....it's a lot!!)


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 Post subject: Re: 21 Gram Pump
PostPosted: Sun Mar 30, 2014 12:57 pm 
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Joined: Sun Mar 23, 2014 2:41 pm
Posts: 11
is there anyone who already got it? (I didn't)


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 Post subject: Re: 21 Gram Pump
PostPosted: Sun Mar 30, 2014 7:51 pm 
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Joined: Mon Jun 06, 2011 7:16 pm
Posts: 380
Location: Irvine, CA
Yes....these do take alot of pumps to get up to ideal pressure if used alone. I keep my small carbon pump in my jersey pocket as a back up when you get more than one flat on a ride. I don't like carrying more than two CO2 bottles.


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 Post subject: Re: 21 Gram Pump
PostPosted: Sun Mar 30, 2014 10:01 pm 
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Joined: Sun Mar 30, 2014 9:41 pm
Posts: 1
Quote:
The pump is so small, it can be stored inside your bicycle frame by dropping a spring down your seat tube...
where it will rattle so much it will drive you insane!


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 Post subject: Re: 21 Gram Pump
PostPosted: Mon Mar 31, 2014 4:31 am 
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in the industry

Joined: Sun Sep 27, 2009 3:08 am
Posts: 88
DMF wrote:
If that tiny thing can reach 150psi I'll eat my entire bike for breakfast. Very much doubt it would ever even get close to 80psi... And even that would be more than a 100 strokes. At one or another point, it just boiles down to the laws and limitations of physics...


Actually it would be quite easy to reach 150, 200, even beyond that with such a small volume of air pumped. The only drawback is that getting to even 150 psi will take you close to 1000 strokes.


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 Post subject: Re: 21 Gram Pump
PostPosted: Mon Mar 31, 2014 9:16 am 
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Joined: Sat Dec 06, 2008 10:14 am
Posts: 963
Location: Sweden
The problem ofcourse being that the pressure per pumping action is far from linear. You might get 80psi with 80 strokes and after that you're rapidly reaching the point where you get 0,1psi per stroke rather than 1,0psi per stroke. I would in practice call that the same thing as not getting any more pressure.

claiming you could get 200psi is just hypothetical nonsense.

_________________
Roadbike
Planet X Stealth w/ drop bars

Mountainbike
Van Nicholas Zion Ti


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 Post subject: Re: 21 Gram Pump
PostPosted: Mon Mar 31, 2014 6:24 pm 
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Joined: Wed Jun 08, 2011 6:08 am
Posts: 105
"It is 100% efficient"

This guy is dumb. I wouldn't buy his product.


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 Post subject: Re: 21 Gram Pump
PostPosted: Wed Apr 09, 2014 4:54 am 
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Joined: Wed Apr 09, 2014 4:33 am
Posts: 50
I just bought a micro pump from my LBS, its Taiwan made, no specific brand, nice alloy construction and weights only 53g but it is extremely small, same size as the ipump, including a small flex hose that pops up from inside and as far as I can tell the pump works great for 100 psi with 300 strokes. I paid 27 usd so it makes a good emergency pump. usually I carry my CO2 bottle and nozzle and just use the pump to reach the desired pressure or in case the CO2 fails I can pump the 300-350 strokes to get the pressure. As someone else pointed I also carry my 2g presta adapter so if I am near any gas station I don't even bother taking other equip out of my backpack. I will post photos here once I get home so you guys have an idea.

Regarding the ipump, honestly the marketing is exagerated and although it may work for some 90-100 psi the money I was considering to throw on this thing I ended up spending on a Barbieri NANA (29g) and also a Lezyne Road Drive for my other bikes.


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 Post subject: Re: 21 Gram Pump
PostPosted: Wed Apr 09, 2014 12:13 pm 
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Joined: Sun Mar 23, 2014 2:41 pm
Posts: 11
This guy is not dumb. Folks whats up with you all?
Did the inventer ever say that it is as easy to use as a compressor you have at home?
No!
It is an emergency solution only fir on the way. For example i take it on my rides together with a Schrader adaptor. It is good for me to fill the tire enough to cycle to the next gas station and refill it properly there.

Mine came today and has a weight of 22.4g, about what i expected.
Before i used the barbieri nana. This one has a weight of 31.8 and was good enough.
The ipump micro works even better, has a longer length of pushing ( i hope you understand what i mean) of about one inch and can produce more power like that. And the hose is really a big benefit comparing with the barbieri nana.

Once again: dumb is the one who expected too much. But the inventor is definitely not dumb. As he adverts it as an emergency solution

Image


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 Post subject: Re: 21 Gram Pump
Posted: Wed Apr 09, 2014 12:13 pm 


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