Change Air In Tires

Rick Ankrum wrote:

Are you saying my miles on the trainer(with a smooth roller) would
extend the time period between air evacuation events?

Depends on your pre-workout meal.

Gift for the obvious (and crass), BS

Rick Ankrum wrote:
8-)

With all the talk of greenhouse gases I am concerned with having tired
air in my bike tubes. How long can I can go between evacuating the air
and putting new air in? I am afraid that the air molecules will all be
pushed to the outer edge of the tire if I do not evacuate the tubes on a
regular basis. This could cause the tire to put too much weight on the
road and thus I am not be able to get at top speed quickly.

Does tapping on the tread move the molecules back into the center of the
tube?


I have gone 4 or 5 years with some of the same air in a tire, tired air
doesn't hold as much pressure, so your tires will go flat after a while,
however new air will often rejuvenate the old air to some degree, so it
often doesn't take much to build back full pressure.

Then again some of the new air, is more polluted then the old air, and
polluted air, is heavier then non-polluted air, so, the air in your
tires is probably lighter then the air you can put in.....

W

"Bonehenge" wrote in message
...
On Sat, 02 Jul 2005 22:31:13 -0500, Rick Ankrum
wrote:


Does tapping on the tread move the molecules back into the center of the
tube?

Air is cheap enough, and recyclable, so I simply replace mine on a
regular schedule.

Soon, I'll be marketing a "Used tire air recovery and recycling kit",
so the old air isn't directly vented to the atmosphere. You can't be
too careful these days. The kit will redistribute the molecules
evenly, making the air suitable for reuse.

Hands off, SHELBROCO! The recovery kit is already patent pending!
G

Another very good reason to lobby your representative for EPA mandates and
gov't funding for airless tire development. A mere 10 billion or so should
get this worthwhile program started.

"The Wogster" wrote: clip) so, the air in your tires is probably lighter
then the air you can put in.....
^^^^^^^^^^^^^^^
If you are really serious about this, take your bike to a mountain top and
inflate the tires there.

Leo Lichtman wrote:
"The Wogster" wrote: clip) so, the air in your tires is probably lighter
then the air you can put in.....
^^^^^^^^^^^^^^^
If you are really serious about this, take your bike to a mountain top and
inflate the tires there.


Kinda difficult around here, considering the current smog advisory,
that's largely do to Ohio, Michigan and Pennsylvania pollution, covers
many areas where traditionally you could find clear air.

W

"Rick Ankrum" wrote:
With all the talk of greenhouse gases I am concerned with having tired air
in my bike tubes. How long can I can go between evacuating the air and
putting new air in?

Twice a year should do. As a minimum you want to replace the air in late
fall and early spring. And most important, don't store the bike bike hanging
it from its rims.

Art Harris

Rick Ankrum wrote in
:

8-)

With all the talk of greenhouse gases I am concerned with having tired
air in my bike tubes. How long can I can go between evacuating the air
and putting new air in? I am afraid that the air molecules will all be
pushed to the outer edge of the tire if I do not evacuate the tubes on
a regular basis. This could cause the tire to put too much weight on
the road and thus I am not be able to get at top speed quickly.

Does tapping on the tread move the molecules back into the center of
the tube?

9-)

If you're not using nitrogen as a filler gas you run the risk of serious
thermal expansion problems at higher speeds.

You should evacuate and refill whenever your routine samples show below 79
v/o N2 in the tube.

A physical sign of this would be when you get a distinct thump every
revolution at the position of the valve stem if you use prestas that have
the valve stem restraints on the inner rim. The rest of the tube is not so
restrained, so with all the molecules at the periphery they will radially
expand the tube against the holding force of the tire beads/carcass; the
valve is a point source of greater restraint, though, and will be somewhat
less radially deflected.

You should evacuate and refill whenever your routine samples show below
79 v/o N2 in the tube.
You want to use helium to reduce weight and top off daily.
Enen though hydrogen is lighter, would it cause destructive chemical
reactions?

wvantwiller wrote:
Rick Ankrum wrote in
:


8-)

With all the talk of greenhouse gases I am concerned with having tired
air in my bike tubes. How long can I can go between evacuating the air
and putting new air in? I am afraid that the air molecules will all be
pushed to the outer edge of the tire if I do not evacuate the tubes on
a regular basis. This could cause the tire to put too much weight on
the road and thus I am not be able to get at top speed quickly.

Does tapping on the tread move the molecules back into the center of
the tube?

9-)


If you're not using nitrogen as a filler gas you run the risk of serious
thermal expansion problems at higher speeds.

You should evacuate and refill whenever your routine samples show below 79
v/o N2 in the tube.

A physical sign of this would be when you get a distinct thump every
revolution at the position of the valve stem if you use prestas that have
the valve stem restraints on the inner rim. The rest of the tube is not so
restrained, so with all the molecules at the periphery they will radially
expand the tube against the holding force of the tire beads/carcass; the
valve is a point source of greater restraint, though, and will be somewhat
less radially deflected.
Will the closing torque on the presta valve make a difference? What is
the correct presta valve torque?

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Mike.A.Schwab wrote:

You want to use helium to reduce weight and top off daily.

Yes, but not just any old helium: for the utmost in weight reduction,
knowledgeable riders use helium-3, which is 25% lighter than the more
common and less desireable helium-4.

Enen though hydrogen is lighter, would it cause destructive
chemical reactions?

Yes, especially where there is a source of ignition nearby.

--
"Bicycling is a healthy and manly pursuit with much
to recommend it, and, unlike other foolish crazes,
it has not died out." -- The Daily Telegraph (1877)