FLCC> Advice re: floor pump

[Ernie Bayles]

Ron,

This is sort of typical behavior.  Since the guage is measuring the 
pressure at the pump it won't give you an accurate read for what's in 
the tire until the pump pressure is greater than the tire pressure, so 
the lack of any or an accurate read upon hook up is typical. 

When pumping begins, the guage will read the "overpressure" that it 
takes to overcome the resistance in the tire valve which makes the 
needle bob up over the tire pressure.  If the valve is a bit sticky, 
this can be a lot (200 lbs) of pressure.  When the needle stops on the 
way down you have the reading for your tire pressure. 

If the needle continues to drop, it's because there is some leakage 
between the tire valve and the pump guage--usually around the fitting at 
the tire valve (sometimes known as the head).  It could also be in the 
valve at the guage. 

Most of this is pretty typical for even the best pumps.  If the pump is 
capable of getting air in the tire without too much sweating and 
swearing I'd consider it a pretty good pump.  If the guage works more 
than half the time you might consider it a great pump. 

I don't have a great pump, but it is 30 years old.  It was great at one 
time.  Cheap pumps are generally inferior on many fronts--inaccurate, 
hard to attach to the tire, lots of pumping effort--so you could 
probably benefit from an upgrade, but I don't have any current 
recommendation.

I'd suggest you simply go to your LBS and try out a couple of models.  
If they work well for you on the tires on you bike you can make your own 
judgement. 

Ernie

racerra wrote:

>Hi All, 
>Last year I bought a cheap floor pump which is working
>alright in terms of pumping air into my tires.  The gauge on
>it, however, leaves a lot to be desired.  It doesn't read at
>all when I first hook it up to the tire. (Is that normal?) 
>When I begin the pump, it reads anywhere from 80 to 110 and
>fluctuates.  It jumps up as I begin to pump then seems to
>drop down as I stop.  I don't think it is losing air at the
>bottom of the stroke.
>What I really need to know is, are these problems typical or
>just due to it being a cheap pump.  Also, any advice about a
>brand/model you would recommend.
>Thanks,
>Ron Acerra
>
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-- 
Ernie Bayles, Architect
209 Utica Street
Ithaca, New York  14850

607-275-3722 (tel and fax)