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Old September 7th 17, 01:23 AM posted to rec.bicycles.tech
John B.[_3_]
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Default Let the Laughing Begin

On Wed, 06 Sep 2017 08:54:53 -0700, Jeff Liebermann
wrote:

On Wed, 06 Sep 2017 13:30:25 +0700, John B.
wrote:

On Tue, 05 Sep 2017 09:52:07 -0700, Jeff Liebermann
wrote:
At one time, I proposed a portable bicycle tire inflator consisting of
something like the automotive automatic shutoff compressor that I'm
using, with an added LiIon rechargeable battery. Or maybe powered
instead by a model airplane gasoline engine. I think I can make it
small enough to be fairly flat and pocket size. A little marketing
research indicated that nobody I asked would pay money for such a
thing but might consider building one from a kit. Very strange but I
decided that it was too risky and let the idea die a natural death.


I've always believed that a "good pump" was one with which one could
inflate the desired tire to the desired pressure :-)


Sigh. Inflate the desired tire at what temperature, with how much
effort, how quickly, to what accuracy, how big a tire, etc? What
works well for a road bicycle, might not be so good inflating an
automobile tire. What works in the shop, may not be so good during a
ride. Of course, there are specialized bicycle pumps optimized for
these and other purposes and conditions. My idea of a "good pump" is
one that will do an adequate job of inflating everything from a high
pressure racing tire (multistage pump), to an air mattress (large
volume piston or vane pump). It might look a bit weird, have
capabilities I might rarely use, probably expensive, but will work for
anything that needs inflation.


You missed the "desired tire to the desired pressure" ;-?


Here's one application for an air pump with which I'm currently
working:
https://www.amazon.com/Carburetor-detector-Replaces-Tillotson-243-504/dp/B06Y542R9S
Yes, it's an air pump. It's used to apply pressure to the carburetor
fuel inlet on a 2 stroke engine (chain saw) to determine if the needle
valve is working properly and not leaking. Apply pressure and it
should open the needle valve at about 15 psi. Let it bleed down, and
it should close again at 5 psi. Pressurized to 10 psi and dunk the
carburetor into a bowl of water while looking for leaks (air bubbles).
A "good pump" should be able to do this as well.


Yup, we used to do that. Blow into the fuel line. While nobody's
cheeks were calibrated in psi it did tell you if the needle valve was
leaking. One did have to spit a bit to get the gasoline taste out of
your mouth though. :-)

The problem here is that this is what I want, not what the GUM (great
unwashed masses) are will to buy. That makes it a "good pump" but
only for me. You may have other ideas.

--
Cheers,

John B.

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