Filling a tube with water

My rear tire flatted today. I did not, alas, have a spare tube or
patch kit handy. The hole was small, a leak under an old patch, but
leaked fast enough to make riding home impractical. So I resorted to
filling the tube with water, using my frame pump (remove plunger, fill
with water, pump into tube). I learned of this technique on this
newsgroup, probably from Jobst Brandt; this was the first time I had
to put it practice. It worked very well, the tire stayed hard and
showed no signs of leaking.

When I got home and "deflated" the tube, I noticed that a considerable
amount of water seemed to have leaked from the tube into the tire.
Possibly this happened during the deflation. Before deflating the tire
I could detect no signs of leaking water.

My question is, why does a tube filled with water leak less (slower)
then one filled with air? I originally thought it was because the
size of the water molecule is considerably larger than an air
molecule, however, I've got to believe that water molecules are much
smaller than the pin hole. The amount of water that appeared to be
between the tube and tire makes makes me think something else is going
on.

Joe Riel

P.S. For those wondering, while riding I could detect no difference
between the water filled tube and an air filled tube.

"Joe Riel" wrote in message
...
| My rear tire flatted today. I did not, alas, have a spare tube or
| patch kit handy. The hole was small, a leak under an old patch, but
| leaked fast enough to make riding home impractical. So I resorted to
| filling the tube with water, using my frame pump (remove plunger, fill
| with water, pump into tube). I learned of this technique on this
| newsgroup, probably from Jobst Brandt; this was the first time I had
| to put it practice. It worked very well, the tire stayed hard and
| showed no signs of leaking.
|
| When I got home and "deflated" the tube, I noticed that a considerable
| amount of water seemed to have leaked from the tube into the tire.
| Possibly this happened during the deflation. Before deflating the
tire
| I could detect no signs of leaking water.
|
| My question is, why does a tube filled with water leak less (slower)
| then one filled with air? I originally thought it was because the
| size of the water molecule is considerably larger than an air
| molecule, however, I've got to believe that water molecules are much
| smaller than the pin hole. The amount of water that appeared to be
| between the tube and tire makes makes me think something else is going
| on.

Next time, use Cytomax, and then you'd have had no leak at all ;-)

Joe Riel wrote:

P.S. For those wondering, while riding I could detect no difference
between the water filled tube and an air filled tube.

Weird. Doesn't it make the wheel incredibly heavy?

Joe Riel wrote:

My rear tire flatted today. I did not, alas, have a spare tube or
patch kit handy. The hole was small, a leak under an old patch, but
leaked fast enough to make riding home impractical. So I resorted to
filling the tube with water, using my frame pump (remove plunger, fill
with water, pump into tube). I learned of this technique on this
newsgroup, probably from Jobst Brandt; this was the first time I had
to put it practice. It worked very well, the tire stayed hard and
showed no signs of leaking. ...
My question is, why does a tube filled with water leak less (slower)
then one filled with air? I originally thought it was because the
size of the water molecule is considerably larger than an air
molecule, however, I've got to believe that water molecules are much
smaller than the pin hole.

I expect the strong hydrogen bonding between water molecules tends to
keep them together rather than escaping through the small hole. This
is also why water has such high surface tension.

Joe Riel writes:

My rear tire flatted today. I did not, alas, have a spare tube or
patch kit handy. The hole was small, a leak under an old patch, but
leaked fast enough to make riding home impractical. So I resorted
to filling the tube with water, using my frame pump (remove plunger,
fill with water, pump into tube). I learned of this technique on
this newsgroup, probably from Jobst Brandt; this was the first time
I had to put it practice. It worked very well, the tire stayed hard
and showed no signs of leaking.

I'm glad to hear that such stories have helped.

When I got home and "deflated" the tube, I noticed that a
considerable amount of water seemed to have leaked from the tube
into the tire. Possibly this happened during the deflation. Before
deflating the tire I could detect no signs of leaking water.

My question is, why does a tube filled with water leak less (slower)
then one filled with air? I originally thought it was because the
size of the water molecule is considerably larger than an air
molecule, however, I've got to believe that water molecules are much
smaller than the pin hole. The amount of water that appeared to be
between the tube and tire makes makes me think something else is
going on.

The viscosity of water is many times that of a gas. Just think of how
long it would take to drain a water bottle with a pin prick in the cap
compared to squeezing it flat if it were empty.

P.S. For those wondering, while riding I could detect no difference
between the water filled tube and an air filled tube.

Well, I've reported that as well. For the shimmy tests for those who
claimed tire weight had a large effect, I filled my usual tire with
water, making sure there was no air in it by the method you used.
Sloshing water has losses while a full load does not. Therefore,
before the tire is completely inflated let out air while the stem is
at the top and push down ton the tire so the stem mouth is at the
highest point.

There is no perception of a heavier wheel except at walking speeds
where some faster turns are often made by us who don't have perfect
balance. At speed this never occurs. I didn't check to see what the
contact patch size was. That might be interesting.

Jobst Brandt

My rear tire flatted today. I did not, alas, have a spare tube or
patch kit handy. The hole was small, a leak under an old patch, but
leaked fast enough to make riding home impractical. So I resorted to
filling the tube with water, using my frame pump
P.S. For those wondering, while riding I could detect no difference
between the water filled tube and an air filled tube.

** STOP THE MADNESS **

Zog The Undeniable writes:

Joe Riel wrote:

P.S. For those wondering, while riding I could detect no difference
between the water filled tube and an air filled tube.

Weird. Doesn't it make the wheel incredibly heavy?

It only took about one water bottle; I don't notice a difference when
I carry one on the frame 8-). If it were the front wheel I might have
noticed a difference in the steering, but on the rear I couldn't feel
any effect. Note, this was on my small wheeled Moulton, which also
has rear suspension.

Joe

writes:

Joe Riel writes:

My rear tire flatted today. I did not, alas, have a spare tube or
patch kit handy. The hole was small, a leak under an old patch, but
leaked fast enough to make riding home impractical. So I resorted
to filling the tube with water, using my frame pump (remove plunger,
fill with water, pump into tube). I learned of this technique on
this newsgroup, probably from Jobst Brandt; this was the first time
I had to put it practice. It worked very well, the tire stayed hard
and showed no signs of leaking.

I'm glad to hear that such stories have helped.

Thanks, they do help. It would have been a bit of a hike to get home.

The viscosity of water is many times that of a gas. Just think of how
long it would take to drain a water bottle with a pin prick in the cap
compared to squeezing it flat if it were empty.

I hadn't thought of viscosity, thanks.


Joe

On Thu, 19 Aug 2004 20:31:14 GMT, Joe Riel wrote:


My question is, why does a tube filled with water leak less (slower)
then one filled with air? I originally thought it was because the
size of the water molecule is considerably larger than an air
molecule, however, I've got to believe that water molecules are much
smaller than the pin hole. The amount of water that appeared to be
between the tube and tire makes makes me think something else is going
on.

Joe Riel

P.S. For those wondering, while riding I could detect no difference
between the water filled tube and an air filled tube.

My WAG would be that not only is water more viscous than air, but the
water isn't under the pressure that air is. Air in the tube is under
considerable pressure and it tries to escape to a lower-pressure zone.
Water isn't under pressure; the tire is hard because water simply
doesn't compress.

larry

On Thu, 19 Aug 2004 20:31:14 GMT, Joe Riel wrote:

My rear tire flatted today. I did not, alas, have a spare tube or
patch kit handy. The hole was small, a leak under an old patch, but
leaked fast enough to make riding home impractical. So I resorted to
filling the tube with water,

Dang. Interesting.

JT

****************************
Remove "remove" to reply
Visit http://www.jt10000.com
****************************