"Strange" object attached to downtube

Check out:

http://tinyurl.com/cd5pr

What is that cylindrical object attached to the downtube of Bobet's
bike?

I've seen these in other pix from the 1950's but have never found an
explanation of what they are.

TIA,

'mook

traditionally, that's a coke holder.

V-Mook wrote:
Check out:

http://tinyurl.com/cd5pr

What is that cylindrical object attached to the downtube of Bobet's
bike?

I've seen these in other pix from the 1950's but have never found an
explanation of what they are.

TIA,

'mook



Turbo?

"V-Mook" wrote in message
oups.com...
Check out:

http://tinyurl.com/cd5pr

What is that cylindrical object attached to the downtube of Bobet's
bike?

Looks like a waterbottle to me....

(ducks)

V-Mook wrote:

Check out:

http://tinyurl.com/cd5pr

What is that cylindrical object attached to the downtube of Bobet's
bike?

I've seen these in other pix from the 1950's but have never found an
explanation of what they are.

TIA,

'mook


I asked this same question two years ago and started a long thread.
It's a "gonfleur", a tire inflator, but not a pump, and not CO2. Lots
of other interesting conjecture though. Here's the archive link.
http://tinyurl.com/8bc8b


--
My bike blog:
http://diabloscott.blogspot.com/

On 8 Aug 2005 16:00:57 -0700, "V-Mook"
wrote:

Check out:

http://tinyurl.com/cd5pr

What is that cylindrical object attached to the downtube of Bobet's
bike?

I've seen these in other pix from the 1950's but have never found an
explanation of what they are.

TIA,

'mook

Dear Mook,

It's a nitrogen cylinder for pumping up flats, the ancestor
of the modern CO2 cartridge---google for gonfleurs. They
also attached these things to the seat tube.

N2 has the slight advantage of being much less soluble than
CO2 in rubber, so it wouldn't lose pressure as fast as tubes
filled with CO2, but unlike CO2 it wasn't a liquid at the
usable pressure and temperature, so the cylinders were much
larger.

Carl Fogel

wrote:

N2 has the slight advantage of being much less soluble than
CO2 in rubber, so it wouldn't lose pressure as fast as tubes
filled with CO2, but unlike CO2 it wasn't a liquid at the
usable pressure and temperature, so the cylinders were much
larger.

Although 100% nitrogen may have its advantages, I have had great
success with a carefully tailored mixture of 78% nitrogen for filling
tires. Use of this compound has resulted in the lowest rolling
resistance that I have been able to perceive. I have noticed that
sometimes merely topping up a tire with the mixture will lower its
apparent rolling resistance dramatically. I began using this mixture
quite some time ago when I seredipitously stumbled upon an inexpensive
source which I believe will serve my needs for at least the next ten
years and probably longer.

I must confess that I have been so pleased with the effectiveness of
the 78% nitrogen mixture that I have not attempted to determine whether
some other percentage such as 75% or 80% might be better, but I suspect
that, in any case, 78% is the sweet spot of the performance/cost curve.


DR

Dirtroadie wrote:
wrote:


N2 has the slight advantage of being much less soluble than
CO2 in rubber, so it wouldn't lose pressure as fast as tubes
filled with CO2, but unlike CO2 it wasn't a liquid at the
usable pressure and temperature, so the cylinders were much
larger.


Although 100% nitrogen may have its advantages, I have had great
success with a carefully tailored mixture of 78% nitrogen for filling
tires. Use of this compound has resulted in the lowest rolling
resistance that I have been able to perceive. I have noticed that
sometimes merely topping up a tire with the mixture will lower its
apparent rolling resistance dramatically. I began using this mixture
quite some time ago when I seredipitously stumbled upon an inexpensive
source which I believe will serve my needs for at least the next ten
years and probably longer.

I know the source of which you speak! Unfortunately the CO2 content
seems to be increasing lately, which is probably why my tires don't hold
air like they used to...

My research suggests that 78.084% nitrogen is the optimum, when
combined with 20.947% Oxygen, 0.934% Argon and 0.033% Carbon Dioxide.

In article . com,
says...


Although 100% nitrogen may have its advantages, I have had great
success with a carefully tailored mixture of 78% nitrogen for filling
tires. Use of this compound has resulted in the lowest rolling
resistance that I have been able to perceive. I have noticed that
sometimes merely topping up a tire with the mixture will lower its
apparent rolling resistance dramatically. I began using this mixture
quite some time ago when I seredipitously stumbled upon an inexpensive
source which I believe will serve my needs for at least the next ten
years and probably longer.

I must confess that I have been so pleased with the effectiveness of
the 78% nitrogen mixture that I have not attempted to determine whether
some other percentage such as 75% or 80% might be better, but I suspect
that, in any case, 78% is the sweet spot of the performance/cost curve.

I want some. How much for a three tires worth?
----------------
Alex