pump grease

charles ramsey said:

I once replaced the grease in a zefal hp pump with dow corning high vacume grease. the pump was
leaky at 120 psi then worked well at 160
psi. does any one know where to get this grease?

I do not. Are you sure it was the type of grease and not simply the fact that the seal was no
longer dry?

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

[email hidden] (charles ramsey) wrote in message
news:<[email hidden]>...

Quoted message said:

I once replaced the grease in a zefal hp pump with dow corning high vacume grease. the pump was
leaky at 120 psi then worked well at 160
psi. does any one know where to get this grease?

Dear Charles,

Google for grease high vacuum dow and you should find a fair number of sites. The link below accepts
orders and offers a table that may interest rec.bicycles.tech engineers, whose informed comments on
whether some super-grease will help me pump up my flat tires are eagerly anticipated.

2spi.comdow corning grease properties.htmlOpen ↗

Carl Fogel

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

Quoted message said:

I once replaced the grease in a zefal hp pump with dow corning high vacume grease. the pump was
leaky at 120 psi then worked well at 160
psi. does any one know where to get this grease?

The cryogenics guy at work gave me some "slick 50" grease for my zefal hpx. Wonderful stuff.

Regards,

Suzy

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

Quoted message said:

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

Quoted message said:

I once replaced the grease in a zefal hp pump with dow corning high vacume grease. the pump was
leaky at 120 psi then worked well at 160
psi. does any one know where to get this grease?

The cryogenics guy at work gave me some "slick 50" grease for my zefal hpx. Wonderful stuff.

Regards,

Suzy

Dear Suzy,

Ah, those cold-hearted cryogenics fellows--promise her anything, but give her some pump grease!

Seriously, what were the details?

Were you cleaning and maintaining a pump that worked fine before and after? (Grease is just grease,
as far as pumps are concerned.)

Or were you trying to fix a wheezing pump with good results that Andrew Muzi has wondered might be
reproduced by any grease? (Grease is just grease, but pumps won't work without enough of it.)

Or did your previously mild-mannered pump that would only reach X psi step into the grease-room
wearing ordinary clothes and emerge wearing a blue body-stocking with a big red S on the chest and
reach X + 20 psi? (Some grease really is better than other grease for sealing pumps, leaking less
and letting them reach higher pressures with fewer, stiffer strokes.)

There must be an answer. Pumps seem to come in a wide range of maximum pressures, so either they
can't seal tightly enough onto the valve stem, their internal valves start to leak sooner, or they
just don't offer enough mechanical advantage to reach higher pressures.

Maybe it's just a slippery question?

Carl Fogel

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

Quoted message said:

Seriously, what were the details?

I had a flat on the way to work, took out my trusty pump, and found it _really_ hard to push. I
could only get the tyre up to 5 bar or so no matter how long I sweated. When I got to work I asked
said cryogenics tech if he had any grease that wouldn't perish the rubber bits in the pump (or my
tubes for that matter). He gave me a dollop of this "Slick 50" stuff (which looks a bit like
vaseline) and it totally transformed my pump, so that it filled the tyre to 8 bar in just a couple
of dozen strokes. I didn't go any further, as I only ever fill my tyres to 8 bar anyway.

I think the main thing about the grease he gave me isn't its ability to seal (it does so admirably)
but rather that it isn't very volatile, so doesn't end up in your tyres.

Regards,

Suzy

I recently had an intersting set of experiences with pumps. Most of my bikes have old Silca pumps
with Camy heads, and they have served me well for years and years. I have one bike that has a
Blackburn frame fit pump, the one with the pivoting handle. Like most of my pumps, it is used
rarely. A couple of weeks ago, while out for a ride, I had a slow leak in one tire and decided to
just keep topping it off rather than fixing it (really, this is usually a bad plan and it's usually
faster just to fix the danged thing properly the first time). Anyway, on one occasion the pump
worked fine; on the second occasion, the weird little spring thing that you push down and rotate to
lock out of the way just unscrewed right off the pump, taking with it the top of the pump and the
piston assembly. I screwed that back together. On the third occasion, just 1.5 miles from home, the
O ring on the piston decided to become unseated. I fixed that three times, without success.

When I got home, I tried lubricating the O ring with silicone grease which seems to have solved that
problem. But jeez, how badly can one company over think and over complicate a simple bicycle pump?
Give me more Silcas!

(Carl Fogel) said:

X psi step into the grease-room wearing ordinary clothes and emerge wearing a blue body-stocking
with a big red S on the chest and reach with fewer, stiffer strokes.)

Quoted message said:

Maybe it's just a slippery question?

Quoted message said:

Carl Fogel

--
Rick Onanian

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

Quoted message said:

I recently had an intersting set of experiences with pumps. Most of my bikes have old Silca pumps
with Camy heads, and they have served me well for years and years. I have one bike that has a
Blackburn frame fit pump, the one with the pivoting handle. Like most of my pumps, it is used
rarely. A couple of weeks ago, while out for a ride, I had a slow leak in one tire and decided to
just keep topping it off rather than fixing it (really, this is usually a bad plan and it's
usually faster just to fix the danged thing properly the first time). Anyway, on one occasion the
pump worked fine; on the second occasion, the weird little spring thing that you push down and
rotate to lock out of the way just unscrewed right off the pump, taking with it the top of the
pump and the piston assembly. I screwed that back together. On the third occasion, just 1.5 miles
from home, the O ring on the piston decided to become unseated. I fixed that three times, without
success.

When I got home, I tried lubricating the O ring with silicone grease which seems to have solved
that problem. But jeez, how badly can one company over think and over complicate a simple bicycle
pump? Give me more Silcas!

Wow people are listening. Why did I do it? because I wanted to extend the life of an old pump
because I was getting pinch flats at 110 psi because Ian Hibell who pushed his bike through the
amazon carried shoe polish when asked why he said take care of your equipment and it will take care
of you. High vacume greese was made for air pumps. If you are going to experiment please let us know
if the greese you use eats the plastic.

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

Quoted message said:

I recently had an intersting set of experiences with pumps. Most of my bikes have old Silca pumps
with Camy heads, and they have served me well for years and years. I have one bike that has a
Blackburn frame fit pump, the one with the pivoting handle. Like most of my pumps, it is used
rarely. A couple of weeks ago, while out for a ride, I had a slow leak in one tire and decided to
just keep topping it off rather than fixing it (really, this is usually a bad plan and it's
usually faster just to fix the danged thing properly the first time). Anyway, on one occasion the
pump worked fine; on the second occasion, the weird little spring thing that you push down and
rotate to lock out of the way just unscrewed right off the pump, taking with it the top of the
pump and the piston assembly. I screwed that back together. On the third occasion, just 1.5 miles
from home, the O ring on the piston decided to become unseated. I fixed that three times, without
success.

When I got home, I tried lubricating the O ring with silicone grease which seems to have solved
that problem. But jeez, how badly can one company over think and over complicate a simple bicycle
pump? Give me more Silcas!

Wow people are listening. Why did I do it? because I wanted to extend the life of an old pump
because I was getting pinch flats at 110 psi because Ian Hibell who pushed his bike through the
amazon carried shoe polish when asked why he said take care of your equipment and it will take care
of you. High vacume greese was made for air pumps. If you are going to experiment please let us know
if the greese you use eats the plastic.