Re: Two stage tire pump?

On 5/10/2025 10:22 AM, bp@www.zefox.net wrote:

Are there any two-stage tire pumps on the market? I'm looking
for a frame-sized pump that makes it a little easier to get
near 100 psi. Best I know of is the Topeak Road Morph, but it's
single stage and takes most of my weight to surpass 100 psi. Not
impossible, but sure to get harder with time.
 A pump that perhaps doubles or triples pressure on the pull stroke
and then delivers output on the push would help a great deal.
 I do have an old "WindPipe", from Specialized. This is two-mode,
not two-stage. It uses a very small-bore cylinder for high pressures
and a co-axial large-bore cylinder for low pressure. The internal seals
gave up and it no longer develops any pressure at all. Far as I can
tell they're no longer offered. It was helpful while it worked, but
being single-stage the volumetric efficiency was always lousy.
 Thanks for reading,
 bob prohaska
 

Such exist:
https://giyopumps.com/blog/what-is-a-2-stage-bike-pump/
and have for quite some time:
https://www.yellowjersey.org/photosfromthepast/n_1pmp_ho.jpg
and you are correct in principle. That said, as you noted, quality, longevity, efficiency and price can be significant factors besides the basic design itself.
n.b. first link above is not an endorsement.
--
Andrew Muzi
am@yellowjersey.org
Open every day since 1 April, 1971