Jobst: Blackburn has made your pump!

GaryG said:

You'd think they'ed spec it with a digital pressure gauge, and an audible
alarm for when you reached the desired pressure.

And there'd have to be braille on the setting buttons, for blind
cyclists, too.

Ryan Cousineau said:

Seen at InterBike:

http://tinyurl.com/7g87o

Quoted message said:

"For 2006, Blackburn's Air Tower 5 CF floor pump has been upgraded
to reach 100psi in a mere 10 strokes. With improved Dual Stage, Dual
Stroke internals..."

Quoted message said:

I have respectfully avoided posting the bit about how the barrel is
made of carbon fiber. Because floor pump buyers are very concerned
about getting the lightest one possible.

To make up for that, FSA built my tensiometer with a main plate of
carbon fiber rather than black anodized aluminum. Carbon is IN!

http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=49&pid=162

The Blackburn pump is a side-by-side as the Zefal blue plastic pump
was. That was the way I built my first pump but I was dissatisfied
with the skewing of the handle so I designed a concentric one that
operates far smoother and one can spin the handle. My two stage
concentric pump is interesting because it is the first one that has
the air outlet at the bottom. I researched this and found that this
was a common problem among designers, the Dunlop Pump going to
extremes to avoid this design feature.

The Dunlop pump is a three stage pump (an odd number of stages being
required for bottom output) and operate two of the stages in parallel
there being only one up-stroke and one down-stroke, making it an
unusually complex pump.

http://home.comcast.net/~carlfogel/download/PUMP_OLD.jpg
http://home.comcast.net/~carlfogel/download/PUMP_NEW.jpg
http://home.comcast.net/~carlfogel/download/PMP_004.jpg
http://home.comcast.net/~carlfogel/download/ASSY_SILCA_CHUCK_RND.jpg

The secret to the concentric pump is the hollow center shaft. It is
simple design features like this that often escape people. The
pressure relief valve on the Silca pump head makes the rubber grommet
last practically forever. I've used this one for more than 20 years.

I sent this stuff to Silca and offered to send them all the detailed
drawings if they were interested. The big Silca label is only a
label. The pump is built here.

Jobst Brandt

Quoted message said:

The secret to the concentric pump is the hollow center shaft. It is
simple design features like this that often escape people. The
pressure relief valve on the Silca pump head makes the rubber grommet
last practically forever. I've used this one for more than 20 years.

I sent this stuff to Silca and offered to send them all the detailed
drawings if they were interested. The big Silca label is only a
label. The pump is built here.

Jobst Brandt

Actually somewhere in the late 80's/early 90's Silca changed their
chuck design that rendered them completely unusable. AFAIK to this day
they are still using that same crappy chuck design.

1. The newer chuck does not rotate independently from the hose. The
older one did.
2. The newer chuck is prone to blow-offs. If it doesn't blow off it's
leaking and can't get anywhere near full pressure without an additional
hand holding the chuck.
3. The newer chuck needs to be completely disassembled to switch
between presta or Schrader. The older chuck you simply reverse the
chuck assembly.

If anyone knows where I can get a vintage 80's Silca (non-track) chuck
I'd sure appreciate some references. As it is I've stopped using the
newer Silca chuck in favor of a cheaper made-in-Taiwan plastic chuck
that at least works and doesn't require fuss.

Quoted message said:

To make up for that, FSA built my tensiometer with a main plate of
carbon fiber rather than black anodized aluminum. Carbon is IN!

http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=49&pid=162

"Unique deflection system gives universal readings irrespective of
spoke gauge"
"No more need for elaborate conversion charts"

huh!?! please explain.

B.C. Cletta said:

Quoted message said:

To make up for that, FSA built my tensiometer with a main plate of
carbon fiber rather than black anodized aluminum. Carbon is IN!

http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=49&pid=162

"Unique deflection system gives universal readings irrespective of
spoke gauge"
"No more need for elaborate conversion charts"

huh!?! please explain.

if it's designed by jobst, it's no surprise. he doesn't think spoke
gauge has any effect on tension deflection - look at his equation in his
book - no allowance for gauge whatsoever. quite extraordinary.

In article <[email hidden]>,

Quoted message said:

The Blackburn pump is a side-by-side as the Zefal blue plastic pump
was.

Quoted message said:

The secret to the concentric pump is the hollow center shaft. It is
simple design features like this that often escape people.

While I haven't seen the Blackburn pump in person, the pictures
and diagrams of it on Blackburn's web site suggest otherwise to me.

http://www.blackburndesign.com/floor_pumps.html

The pencil sketch on the right seems to indicate that the pump's
output is through a hollow centre shaft, there being no hose out the top
of the handle, and no other way for the high-pressure chamber's air to
exit. The handle itself is attached only to the intermediate tube,
with no apparant attachment to an adjacent pump stage. I believe this
pump is concentric, rather than side-by-side.

I think this pump is very similar to your coaxial design,
Jobst, but it does appear to have some extra complication. There is a red
button on the foot of the pump, which is described as a 'stage selector
button' in the description for the aluminum barreled Air Tower 5.

What I think this means is that the large 'low-pressure cup' in
your design, is an O-ring seal in the Blackburn (or some equivalent like
back-to-back cups). The inlet for Blackburn's low-pressure chamber
would be some sort of check-valve at the top of the pump rather than
relying on the cup to do the valving. The space beneath the large seal
is used as a second pump, with its own inlet check-valve at the pump
foot, and its own outlet check-valve feeding the hose.

This bottom pump operates in parallel with the two-stage pump
on top of it for a high-volume mode. The button on the pump foot
defeats the inlet check-valve to disable the bottom pump, letting the
2-stage pump operate alone for the high-pressure mode.

-Luns

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Ryan Cousineau said:

Seen at InterBike:

http://tinyurl.com/7g87o

Quoted message said:

"For 2006, Blackburn's Air Tower 5 CF floor pump has been upgraded
to reach 100psi in a mere 10 strokes. With improved Dual Stage, Dual
Stroke internals..."

Quoted message said:

I have respectfully avoided posting the bit about how the barrel is
made of carbon fiber. Because floor pump buyers are very concerned
about getting the lightest one possible.

To make up for that, FSA built my tensiometer with a main plate of
carbon fiber rather than black anodized aluminum. Carbon is IN!

http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=49&pid=162

The Blackburn pump is a side-by-side as the Zefal blue plastic pump
was. That was the way I built my first pump but I was dissatisfied
with the skewing of the handle so I designed a concentric one that
operates far smoother and one can spin the handle. My two stage
concentric pump is interesting because it is the first one that has
the air outlet at the bottom. I researched this and found that this
was a common problem among designers, the Dunlop Pump going to
extremes to avoid this design feature.

The Dunlop pump is a three stage pump (an odd number of stages being
required for bottom output) and operate two of the stages in parallel
there being only one up-stroke and one down-stroke, making it an
unusually complex pump.

http://home.comcast.net/~carlfogel/download/PUMP_OLD.jpg
http://home.comcast.net/~carlfogel/download/PUMP_NEW.jpg
http://home.comcast.net/~carlfogel/download/PMP_004.jpg
http://home.comcast.net/~carlfogel/download/ASSY_SILCA_CHUCK_RND.jpg

The secret to the concentric pump is the hollow center shaft. It is
simple design features like this that often escape people. The
pressure relief valve on the Silca pump head makes the rubber grommet
last practically forever. I've used this one for more than 20 years.

I sent this stuff to Silca and offered to send them all the detailed
drawings if they were interested. The big Silca label is only a
label. The pump is built here.

Jobst Brandt

I do think you have great stuff and I think your design would be great. I'd
love to have a pump and or pump head that actually worked for more than five
minutes, before it turned to [censored].
Unfortunately I think all the manufacturers would rather use the "planned
obsolescence" rip off method of sticking it to all the customers. I have
three floor pumps and five bike pumps that are all [censored] laying around now.
I really hate it when you can't even get a pump right out of the box to work
without needing three hands to hold the pump head straight (and it still
leaks too) and still be able to pump up the tire OK.

Earl Bollinger said:

I do think you have great stuff and I think your design would be great. I'd
love to have a pump and or pump head that actually worked for more than five
minutes, before it turned to [censored].
Unfortunately I think all the manufacturers would rather use the "planned
obsolescence" rip off method of sticking it to all the customers. I have
three floor pumps and five bike pumps that are all [censored] laying around now.
I really hate it when you can't even get a pump right out of the box to work
without needing three hands to hold the pump head straight (and it still
leaks too) and still be able to pump up the tire OK.

I'm using the cheapest floor pump I've ever owned -- a Nashbar Blue
pump - and am shocked by how well it works. I've mainly had Silca and
Zefal/SKS pumps, plus one Topeak. This cheap Nashbar pump (less than
$20) is great. Just clamp on the head and it holds well.

Whether is lasts long is another story, but at that price if I get a
couple of years out of it I'll be happy. If it goes longer, that's
even better.

JT

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Luns Tee said:

Quoted message said:

The Blackburn pump is a side-by-side as the Zefal blue plastic pump
was.

Quoted message said:

Quoted message said:

The secret to the concentric pump is the hollow center shaft. It
is simple design features like this that often escape people.

Quoted message said:

While I haven't seen the Blackburn pump in person, the pictures and
diagrams of it on Blackburn's web site suggest otherwise to me.

http://www.blackburndesign.com/floor_pumps.html

Quoted message said:

The pencil sketch on the right seems to indicate that the pump's
output is through a hollow centre shaft, there being no hose out the
top of the handle, and no other way for the high-pressure chamber's
air to exit. The handle itself is attached only to the intermediate
tube, with no apparent attachment to an adjacent pump stage. I
believe this pump is concentric, rather than side-by-side.

With a side-by-side, the high pressure cylinder pushed downward and
discharges at the bottom if the designer didn't build it upside down.
However, the Air Tower is a concentric pump with the high pressure
discharge at the top. You'll notice that the hose appears to come out
of the gauge that is at the top of the pump. How the air gets up
there from the moving inner cylinder is unclear. I guess they must
have a hollow piston rod and then pipe it back up to the top.

Quoted message said:

I think this pump is very similar to your coaxial design, Jobst, but
it does appear to have some extra complication. There is a red
button on the foot of the pump, which is described as a 'stage
selector button' in the description for the aluminum barreled Air
Tower 5.

If I could only find one of these things in a LBS it might explain
things. You'll notice the gauge on my pump is at the base where the
air comes out. I have heard that some people believe that is too far
away for their eyesight. The large (Rainbird) gauge with large
numbers to 200psi does that adequately for all the folks that use my
pump but then the complaint may be for a tiny dial faces on some
pumps.

http://www.rainbird.com/diy/products/accessories/p2gauge.htm

Quoted message said:

What I think this means is that the large 'low-pressure cup' in your
design, is an O-ring seal in the Blackburn (or some equivalent like
back-to-back cups). The inlet for Blackburn's low-pressure chamber
would be some sort of check-valve at the top of the pump rather than
relying on the cup to do the valving. The space beneath the large
seal is used as a second pump, with its own inlet check-valve at the
pump foot, and its own outlet check-valve feeding the hose.

O-ring pistons have large friction and do not last long because they
run with high contact pressure. In contrast a piston cup has a ligh
tload against thre cylinder wall and is sealed by the pressure of the
fluid being pumped. That's why there are piston cups. Although I am
using a Silca frame pump leather, I have replacement synthetic piston
cups that will certainly last more than my lifetime if the one in my
pump wears out. What ultimately kills the leather is high temperature
caused by compressing air together with the force.

http://www.epm.com/piston_cup_install.htm

That is why the Silca Impero frame pump had an aluminum shield to
protect the user's hand from the plastic body as it got hot. This
only mattered in the days of tubulars where we pumped up both tires
essentially from scratch, 60psi being as good as flat with respect to
inflation work.

Quoted message said:

This bottom pump operates in parallel with the two-stage pump on top
of it for a high-volume mode. The button on the pump foot defeats
the inlet check-valve to disable the bottom pump, letting the
2-stage pump operate alone for the high-pressure mode.

How condescending. I buy a two stage pump to save work and they say,
if you aren't strong enough to lift the pre-stage, cut it out.

Jobst Brandt

<[email hidden]> wrote in message
news:[email hidden]...
The big Silca label is only a

Quoted message said:

label. The pump is built here.

Sorry if I missed something, but this is a prototype, right? How satisfied
are you with it?

David Rees said:

The big Silca label is only a label. The pump is built here.

Quoted message said:

Sorry if I missed something, but this is a prototype, right? How
satisfied are you with it?

This is a home project. At the time a bit more than two dozen of
these pumps were built for me an my bikie friends. None were sold.
It's everything I expected of a pump and it has worked well for the
about 20 or so years. The pumps are ageless, being all stainless steel
tubes and aluminum parts. If you are a mechanical person, you may
appreciate the problems addressed by the design as you look at the
cross sections.

Jobst Brandt

Brian Huntley said:

And there'd have to be braille on the setting buttons, for blind
cyclists, too.

Not as silly as you might think. There are many blind tandemists. Bob
Bristow of Reading, Berkshire in the UK is not only among their number
but also earns his living as a cycle mechanic. His work is reputed to
be of rather superior quality.

--
Dave...

I can see it now. Zefal will counter with a "Triple Shot" pump that
produces 100 psi in 9 strokes. Pretty soon Stroke-lightening will be
the new rage and Minoura's final Volley will reach 100 PSI in 1/3rd of
a stroke, and blow the tires off the rim in 2/3rd of a stroke.

At that point, the pump makers will begin anew to focus on the truly
important issue in pumping, which is floor-pump lightness. And the
retro riders will yearn for this old Blackburn pump which was lighter
than any other pump but required a horrendous 10 strokes to reach 100
psi.

- Don Gillies
San Diego, CA

jim beam said:

B.C. Cletta said:

Quoted message said:

To make up for that, FSA built my tensiometer with a main plate of
carbon fiber rather than black anodized aluminum. Carbon is IN!

http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=49&pid=162

"Unique deflection system gives universal readings irrespective of
spoke gauge"
"No more need for elaborate conversion charts"

huh!?! please explain.

if it's designed by jobst, it's no surprise. he doesn't think spoke
gauge has any effect on tension deflection - look at his equation in his
book - no allowance for gauge whatsoever. quite extraordinary.

huh!?! please explain. (i'm looking at Fig 67 in 2nd ed.)

B.C. Cletta said:

jim beam said:

B.C. Cletta said:

>To make up for that, FSA built my tensiometer with a main plate of
>carbon fiber rather than black anodized aluminum. Carbon is IN!
>
>http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=49&pid=162

"Unique deflection system gives universal readings irrespective of
spoke gauge"
"No more need for elaborate conversion charts"

huh!?! please explain.

if it's designed by jobst, it's no surprise. he doesn't think spoke
gauge has any effect on tension deflection - look at his equation in his
book - no allowance for gauge whatsoever. quite extraordinary.

huh!?! please explain. (i'm looking at Fig 67 in 2nd ed.)

i'm looking at fig 66 in the 3rd edition. jobst has it as tension =
force / 2 sin theta. i see no allowance for spoke gauge in there.
rhetorically speaking, do you /really/ expect a 1" diameter spoke to
deflect the same amount over a 4" span as a 0.063" one? jobst's
equation suggests it would.

Southern Comfort said:

Quoted message said:

Quoted message said:

>> To make up for that, FSA built my tensiometer with a main plate of
>> carbon fiber rather than black anodized aluminum. Carbon is IN!

http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=49&pid=162

Quoted message said:

Quoted message said:

Quoted message said:

> "Unique deflection system gives universal readings irrespective
> of spoke gauge" "No more need for elaborate conversion charts"

Quoted message said:

Quoted message said:

Quoted message said:

> huh!?! please explain.

Quoted message said:

Quoted message said:

Quoted message said:

if it's designed by jobst, it's no surprise. he doesn't think
spoke gauge has any effect on tension deflection - look at his
equation in his book - no allowance for gauge whatsoever. quite
extraordinary.

huh!?! please explain. (i'm looking at Fig 67 in 2nd ed.)

Quoted message said:

i'm looking at fig 66 in the 3rd edition. jobst has it as tension =
force / 2 sin theta. i see no allowance for spoke gauge in there.
rhetorically speaking, do you /really/ expect a 1" diameter spoke to
deflect the same amount over a 4" span as a 0.063" one? jobst's
equation suggests it would.

You seem to not agree that tension in a thin wire is close to the
values of the ideal condition defined by that simple equation. Had
you bought one of these instruments, you would have noticed that
calibration charts made on spokes in a tensile tester are shipped with
each instrument. The equation is there to demonstrate the principal
of operation.

As it turns out, by using a high precision dial gauge, that has a
resolution of 0.01mm, allows using a light test load that is not
materially affected by the bending stiffness of spokes over a 100mm
span and that the calibration curves for 1.6mm and 1.8mm diameter
spokes are so close that a user need only remember one deflection for
the two kinds of spokes, as well as thinner flat spokes. Spoke
tension to the 0.1N may be interesting as a theoretical pursuit but
most people who use tensiometers when building wheels use the
instrument to check the overall tension in a wheel by sampling rather
than measuring every spoke to fine precision.

It seems you don't use a tensiometer from what you say.

Jobst Brandt

Quoted message said:

Southern Comfort said:

Quoted message said:

>>>To make up for that, FSA built my tensiometer with a main plate of
>>>carbon fiber rather than black anodized aluminum. Carbon is IN!

http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=49&pid=162

Quoted message said:

Quoted message said:

>>"Unique deflection system gives universal readings irrespective
>>of spoke gauge" "No more need for elaborate conversion charts"

Quoted message said:

Quoted message said:

>> huh!?! please explain.

Quoted message said:

Quoted message said:

>if it's designed by jobst, it's no surprise. he doesn't think
>spoke gauge has any effect on tension deflection - look at his
>equation in his book - no allowance for gauge whatsoever. quite
>extraordinary.

huh!?! please explain. (i'm looking at Fig 67 in 2nd ed.)

Quoted message said:

i'm looking at fig 66 in the 3rd edition. jobst has it as tension =
force / 2 sin theta. i see no allowance for spoke gauge in there.
rhetorically speaking, do you /really/ expect a 1" diameter spoke to
deflect the same amount over a 4" span as a 0.063" one? jobst's
equation suggests it would.

You seem to not agree that tension in a thin wire is close to the
values of the ideal condition defined by that simple equation. Had
you bought one of these instruments, you would have noticed that
calibration charts made on spokes in a tensile tester are shipped with
each instrument. The equation is there to demonstrate the principal
of operation.

don't smoke screen jobst - the equation is incomplete because you make
no allowance for spoke thickness. have you seen the mavic zicral spokes
by any chance? if you'd bothered to do the math properly, /then/
approximate on thicknesses, that would be different. you do it for
spoke elongation as part of length calculation, and note that it makes
little difference in practice, which is fine, but the principle is
demonstrated. with tensiometer deflection you don't bother. there is
no attempt to explain why. and when fsa use marketing literature for
the the tool /you/ allegedly designed stating "Unique deflection system
gives universal readings irrespective of spoke gauge", in a modern
environment commonly using spokes in a range from 1.5mm to over 3mm
[ignoring the world of motorcycles of course], then you're making a
serious omission. based on your other, er, "expertise", one could
easily conclude that it's because you didn't know.

Quoted message said:

As it turns out, by using a high precision dial gauge, that has a
resolution of 0.01mm, allows using a light test load that is not
materially affected by the bending stiffness of spokes over a 100mm
span and that the calibration curves for 1.6mm and 1.8mm diameter
spokes are so close that a user need only remember one deflection for
the two kinds of spokes, as well as thinner flat spokes. Spoke
tension to the 0.1N may be interesting as a theoretical pursuit but
most people who use tensiometers when building wheels use the
instrument to check the overall tension in a wheel by sampling rather
than measuring every spoke to fine precision.

vague hand waving in an attempt to justify ineptitude.

Quoted message said:

It seems you don't use a tensiometer from what you say.

ah, the old jobstian lie in attempt to distract. sorry jobst, no dice.

Quoted message said:

Jobst Brandt

Ok, I've seen this subject here off and on a few times now. It seems to
me that some people would like to see a bicycle floor pump pump up a
standard 700 X 23 tire to 100 psi in 10 strokes or less. Right now it
takes me around 26 strokes to get to 100 psi using my Topeak JoeBlow.
So why not just make the stroke barrel diameter 3 times bigger? Instead
of the approximate 3.8 psi I'm getting now per stroke I'd get 11.4.
100/11.4= 8.77 strokes.

Kenny who? said:

Ok, I've seen this subject here off and on a few times now. It seems
to me that some people would like to see a bicycle floor pump pump
up a standard 700 X 23 tire to 100 psi in 10 strokes or less. Right
now it takes me around 26 strokes to get to 100 psi using my Topeak
JoeBlow. So why not just make the stroke barrel diameter 3 times
bigger? Instead of the approximate 3.8 psi I'm getting now per
stroke I'd get 11.4. 100/11.4= 8.77 strokes.

The piston diameters of pumps are designed for the acceptable strength
of the user. As you can see, today's riders are not up to pumping the
old Silca Impero frame pump so it has vanished from the scene. I
recall many complaints that it was too hard to use. Often, in
frustration, users broke of the valve stem because they did not
realize that the pump was intended to be used between the two hands.
Holding the tire and pressing on the handle doesn't work.

Now if a floor pump were larger in diameter than the one I included in
my earlier posting, you wouldn't get many takers. That pump has a
1.625" diameter main tube that is more force than most riders wish to
exert. For that reason, most of the pumps that were built in this
style used a 1.5" OD main tube. Drawings exist for both size pumps.

Jobst Brandt