Mini Pump

On Monday, May 10, 2021 at 4:12:22 PM UTC-7, James wrote:
On 10/5/21 6:45 pm, Lou Holtman wrote:
Op maandag 10 mei 2021 om 07:45:24 UTC+2 schreef James:
On 10/5/21 11:50 am, Frank Krygowski wrote:

It might be handy to see a chart of "pump strokes to 100 psi"
for various brands and models, starting from an empty tube.


Don't forget effort (force) to achieve said pressure.

Diameter and length affects volume / stroke.

Diameter also affects force @ pressure.

To minimize force and strokes, opt for smaller diameter and longer
barrel.

However - is it still a "mini pump" with a long barrel?

I've got a Lezyne road drive pump for my road bike with up to 25mm
tyres @ 100psi, and a higher volume Lezyne pump for my gravel bike
that has 42mm tyres @ 50psi.

100psi is easily achievable for the road bike, but I wouldn't want
to use the larger diameter & volume gravel bike pump to reach
100psi, though it might take fewer strokes.


100 psi easily achieved with a minipump? I don't believe that. Did
you ever checked that?

Yes Lou. I tested it years ago, but for you I tried again. To save
time I pumped my front 23mm tyre to 100psi using my Silca floor pump,
then attached my Lezyne Road Drive mini pump and applied another 40
strokes. Then I reconnected my Silca floor pump and checked the
pressure. It was near to 120psi.

You must have strong arms -- but really short arms like a T-Rex. I think T-Rex arms would be perfect for a mini-pump.

I could probably get that pressure with my Road Morph with the pump on the ground and the mini foot-peg extended, but not with my various other mini-pumps. 80-90PSI would be a big win.

-- Jay Beattie.

On Monday, May 10, 2021 at 6:29:04 PM UTC-5, jbeattie wrote:
On Monday, May 10, 2021 at 4:12:22 PM UTC-7, James wrote:
On 10/5/21 6:45 pm, Lou Holtman wrote:
Op maandag 10 mei 2021 om 07:45:24 UTC+2 schreef James:
On 10/5/21 11:50 am, Frank Krygowski wrote:

It might be handy to see a chart of "pump strokes to 100 psi"
for various brands and models, starting from an empty tube.


Don't forget effort (force) to achieve said pressure.

Diameter and length affects volume / stroke.

Diameter also affects force @ pressure.

To minimize force and strokes, opt for smaller diameter and longer
barrel.

However - is it still a "mini pump" with a long barrel?

I've got a Lezyne road drive pump for my road bike with up to 25mm
tyres @ 100psi, and a higher volume Lezyne pump for my gravel bike
that has 42mm tyres @ 50psi.

100psi is easily achievable for the road bike, but I wouldn't want
to use the larger diameter & volume gravel bike pump to reach
100psi, though it might take fewer strokes.


100 psi easily achieved with a minipump? I don't believe that. Did
you ever checked that?

Yes Lou. I tested it years ago, but for you I tried again. To save
time I pumped my front 23mm tyre to 100psi using my Silca floor pump,
then attached my Lezyne Road Drive mini pump and applied another 40
strokes. Then I reconnected my Silca floor pump and checked the
pressure. It was near to 120psi.
You must have strong arms -- but really short arms like a T-Rex. I think T-Rex arms would be perfect for a mini-pump.

I could probably get that pressure with my Road Morph with the pump on the ground and the mini foot-peg extended, but not with my various other mini-pumps. 80-90PSI would be a big win.

-- Jay Beattie.
You got one set of strong arms............the deacon not so blessed.
Deacon mark

On 5/10/2021 6:12 PM, James wrote:
On 10/5/21 6:45 pm, Lou Holtman wrote:
Op maandag 10 mei 2021 om 07:45:24 UTC+2 schreef James:
On 10/5/21 11:50 am, Frank Krygowski wrote:

It might be handy to see a chart of "pump strokes to 100
psi"
for various brands and models, starting from an empty tube.


Don't forget effort (force) to achieve said pressure.

Diameter and length affects volume / stroke.

Diameter also affects force @ pressure.

To minimize force and strokes, opt for smaller diameter
and longer
barrel.

However - is it still a "mini pump" with a long barrel?

I've got a Lezyne road drive pump for my road bike with
up to 25mm
tyres @ 100psi, and a higher volume Lezyne pump for my
gravel bike
that has 42mm tyres @ 50psi.

100psi is easily achievable for the road bike, but I
wouldn't want
to use the larger diameter & volume gravel bike pump to
reach
100psi, though it might take fewer strokes.


100 psi easily achieved with a minipump? I don't believe
that. Did
you ever checked that?


Yes Lou. I tested it years ago, but for you I tried again.
To save time I pumped my front 23mm tyre to 100psi using my
Silca floor pump, then attached my Lezyne Road Drive mini
pump and applied another 40 strokes. Then I reconnected my
Silca floor pump and checked the pressure. It was near to
120psi.




The manufacturer humbly notes that this is the best product
humans have ever made:
https://ride.lezyne.com/products/1-mp-rddr-v2l04

But under 'specs' doesn't list the piston diameter which is
the crucial dimension.

A one-square-inch piston (1-1/4" dia) needs 100 lbs of
muscle to make 100psi. A half-inch diameter needs about 20
pounds (and 5x number of strokes if the length is the same)


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 5/10/2021 8:50 PM, AMuzi wrote:
On 5/10/2021 6:12 PM, James wrote:
On 10/5/21 6:45 pm, Lou Holtman wrote:
Op maandag 10 mei 2021 om 07:45:24 UTC+2 schreef James:
On 10/5/21 11:50 am, Frank Krygowski wrote:

It might be handy to see a chart of "pump strokes to 100
psi"
for various brands and models, starting from an empty tube.


Don't forget effort (force) to achieve said pressure.

Diameter and length affects volume / stroke.

Diameter also affects force @ pressure.

To minimize force and strokes, opt for smaller diameter
and longer
barrel.

However - is it still a "mini pump" with a long barrel?

I've got a Lezyne road drive pump for my road bike with
up to 25mm
tyres @ 100psi, and a higher volume Lezyne pump for my
gravel bike
that has 42mm tyres @ 50psi.

100psi is easily achievable for the road bike, but I
wouldn't want
to use the larger diameter & volume gravel bike pump to
reach
100psi, though it might take fewer strokes.


100 psi easily achieved with a minipump? I don't believe
that. Did
you ever checked that?


Yes Lou.Â* I tested it years ago, but for you I tried again.
To save time I pumped my front 23mm tyre to 100psi using my
Silca floor pump, then attached my Lezyne Road Drive mini
pump and applied another 40 strokes.Â* Then I reconnected my
Silca floor pump and checked the pressure.Â* It was near to
120psi.




The manufacturer humbly notes that this is the best product humans have
ever made:
https://ride.lezyne.com/products/1-mp-rddr-v2l04

But under 'specs' doesn't list the piston diameter which is the crucial
dimension.

Also doesn't list the number of strokes to fill a typical tire to 100
psi. Again, that should be standard info.

A one-square-inch piston (1-1/4" dia) needs 100 lbs of muscle to make
100psi. A half-inch diameter needs about 20 pounds (and 5x number of
strokes if the length is the same)



--
- Frank Krygowski

On 11/5/21 9:29 am, jbeattie wrote:
On Monday, May 10, 2021 at 4:12:22 PM UTC-7, James wrote:
On 10/5/21 6:45 pm, Lou Holtman wrote:


100 psi easily achieved with a minipump? I don't believe that.
Did you ever checked that?

Yes Lou. I tested it years ago, but for you I tried again. To save
time I pumped my front 23mm tyre to 100psi using my Silca floor
pump, then attached my Lezyne Road Drive mini pump and applied
another 40 strokes. Then I reconnected my Silca floor pump and
checked the pressure. It was near to 120psi.

You must have strong arms -- but really short arms like a T-Rex. I
think T-Rex arms would be perfect for a mini-pump.

I could probably get that pressure with my Road Morph with the pump
on the ground and the mini foot-peg extended, but not with my
various other mini-pumps. 80-90PSI would be a big win.



I stand about 190cm tall and my arm span is similar if not more. So no,
I don't have short arms. I'm not very bulky either, at about 75kg.

I don't think my arms are very strong. I certainly can't do many
pushups. Maybe 10?

I read somewhere that the road drive is 17mm dia. Maybe the internal
dia is 15mm? That is about 177mm^2. 100psi is 689476 Pa, which is
Newtons / m^2. Converting to N / 177mm^2 is 121.84N, or 12.4kg of force
to achieve 100psi.

I can't be bothered going out to measure precisely, but I think my calcs
are in the ball park. I'd be happy for someone to verify. Frank?

--
JS

On 11/5/21 12:26 pm, James wrote:
On 11/5/21 9:29 am, jbeattie wrote:
On Monday, May 10, 2021 at 4:12:22 PM UTC-7, James wrote:
On 10/5/21 6:45 pm, Lou Holtman wrote:


100 psi easily achieved with a minipump? I don't believe that.
Did you ever checked that?

Yes Lou. I tested it years ago, but for you I tried again. To save
time I pumped my front 23mm tyre to 100psi using my Silca floor
pump, then attached my Lezyne Road Drive mini pump and applied
another 40 strokes. Then I reconnected my Silca floor pump and
checked the pressure. It was near to 120psi.

You must have strong arms -- but really short arms like a T-Rex.Â* I
think T-Rex arms would be perfect for a mini-pump.

I could probably get that pressure with my Road Morph with the pump
on the ground and the mini foot-peg extended,Â* but not with my
various other mini-pumps.Â* 80-90PSI would be a big win.



I stand about 190cm tall and my arm span is similar if not more.Â* So no,
I don't have short arms.Â* I'm not very bulky either, at about 75kg.

I don't think my arms are very strong.Â* I certainly can't do many
pushups.Â* Maybe 10?

I read somewhere that the road drive is 17mm dia.Â* Maybe the internal
dia is 15mm?Â* That is about 177mm^2.Â* 100psi is 689476 Pa, which is
Newtons / m^2.Â* Converting to N / 177mm^2 is 121.84N, or 12.4kg of force
to achieve 100psi.

I can't be bothered going out to measure precisely, but I think my calcs
are in the ball park.Â* I'd be happy for someone to verify.Â* Frank?



Ok, after Andrew's post I did measure. The bore/piston diameter is damn
close to 17mm. That means my previous calc needs to be modified a
little. The force comes to 16kg.

--
JS

On 11/5/21 12:04 pm, Frank Krygowski wrote:


Also doesn't list the number of strokes to fill a typical tire to 100
psi. Again, that should be standard info.


Define "typical".

--
JS

On Monday, May 10, 2021 at 10:49:36 PM UTC-4, James wrote:
On 11/5/21 12:04 pm, Frank Krygowski wrote:


Also doesn't list the number of strokes to fill a typical tire to 100
psi. Again, that should be standard info.

Define "typical".

What I use, obviously! ;-)

More seriously, the definition wouldn't matter much as long as it was used consistently
for comparing a variety of pumps. What's the volume of (say) a 25mm tire? Maybe 67 in^3
or 1100 cubic centimeters? Use a rigid tank of that volume fitted with a schrader and a presta
valve.

- Frank Krygowski

Op dinsdag 11 mei 2021 om 01:12:22 UTC+2 schreef James:
On 10/5/21 6:45 pm, Lou Holtman wrote:
Op maandag 10 mei 2021 om 07:45:24 UTC+2 schreef James:
On 10/5/21 11:50 am, Frank Krygowski wrote:

It might be handy to see a chart of "pump strokes to 100 psi"
for various brands and models, starting from an empty tube.


Don't forget effort (force) to achieve said pressure.

Diameter and length affects volume / stroke.

Diameter also affects force @ pressure.

To minimize force and strokes, opt for smaller diameter and longer
barrel.

However - is it still a "mini pump" with a long barrel?

I've got a Lezyne road drive pump for my road bike with up to 25mm
tyres @ 100psi, and a higher volume Lezyne pump for my gravel bike
that has 42mm tyres @ 50psi.

100psi is easily achievable for the road bike, but I wouldn't want
to use the larger diameter & volume gravel bike pump to reach
100psi, though it might take fewer strokes.


100 psi easily achieved with a minipump? I don't believe that. Did
you ever checked that?

Yes Lou. I tested it years ago, but for you I tried again. To save
time I pumped my front 23mm tyre to 100psi using my Silca floor pump,
then attached my Lezyne Road Drive mini pump and applied another 40
strokes. Then I reconnected my Silca floor pump and checked the
pressure. It was near to 120psi.


--
JS


That is impressive.

Lou

On 5/10/2021 9:26 PM, James wrote:
On 11/5/21 9:29 am, jbeattie wrote:
On Monday, May 10, 2021 at 4:12:22 PM UTC-7, James wrote:
On 10/5/21 6:45 pm, Lou Holtman wrote:


100 psi easily achieved with a minipump? I don't believe
that.
Did you ever checked that?

Yes Lou. I tested it years ago, but for you I tried
again. To save time I pumped my front 23mm tyre to 100psi
using my Silca floor
pump, then attached my Lezyne Road Drive mini pump and
applied
another 40 strokes. Then I reconnected my Silca floor
pump and
checked the pressure. It was near to 120psi.

You must have strong arms -- but really short arms like a
T-Rex. I
think T-Rex arms would be perfect for a mini-pump.

I could probably get that pressure with my Road Morph with
the pump
on the ground and the mini foot-peg extended, but not
with my
various other mini-pumps. 80-90PSI would be a big win.



I stand about 190cm tall and my arm span is similar if not
more. So no, I don't have short arms. I'm not very bulky
either, at about 75kg.

I don't think my arms are very strong. I certainly can't do
many pushups. Maybe 10?

I read somewhere that the road drive is 17mm dia. Maybe the
internal dia is 15mm? That is about 177mm^2. 100psi is
689476 Pa, which is Newtons / m^2. Converting to N /
177mm^2 is 121.84N, or 12.4kg of force to achieve 100psi.

I can't be bothered going out to measure precisely, but I
think my calcs are in the ball park. I'd be happy for
someone to verify. Frank?


Probably close enough, considering your report of 'not
extreme effort'.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971