Tires Gradually Go Flat in Storage

[jim beam]

[email protected] wrote:
> Leo Lichtman writes:
>
>> A hydrogen atom consists of one proton in the nucleus, with one
>> electron orbiting around it. A hydrogen molecule consists of a pair
>> of hydrogen atoms which complete their electron shells by sharing
>> their electrons. A helium atom consists of a nucleus with two
>> protons, and two electrons orbiting around it. Thus, they have the
>> same molecular weight, but the hydrogen molecule is approximately
>> twice as large, because the protons are not together in the same
>> nucleus. The actual sizes do not need to be known for this to be
>> understood.
>
> So what affects diffusion through an inner tube if it isn't given by
> these parameters?

it sure as heck isn't atomic number of noble gases!!!


>
> It has been my experience that in the days of latex tubes in Clement
> tubular tires, cold weather allowed us to ride two days instead of
> one after pumping to about 100psi on a bicycle tour.

cute little story.

 

[jim beam]

Michael Press wrote:
> In article
> <[email protected]>,
> [email protected] wrote:
>
>> On Thu, 01 Nov 2007 22:41:48 GMT, Michael Press <[email protected]>
>> wrote:
>>
>>> In article
>>> <[email protected]>,
>>> [email protected] wrote:
>>>
>>>> On Thu, 01 Nov 2007 04:44:55 -0500, Ben C <[email protected]> wrote:
>>>>
>>>>> On 2007-11-01, jim beam <[email protected]> wrote:
>>>>>> Michael Press wrote:
>>>>> [...]
>>>>>>> What are the sizes? What is "much larger"?
>>>>>>>
>>>>>> what's the matter michael? is your web browser broken?
>>>>> According to http://en.wikipedia.org/wiki/Molecule#Molecular_size, H2 is
>>>>> the smallest diatomic molecule and is roughly 1.48 Angstroms in length.
>>>>> That's about 0.15nm.
>>>>>
>>>>> As for a Helium atom, this page:
>>>>> http://zebu.uoregon.edu/~soper/Sun/step0.html says it's 10-10m, which is
>>>>> 0.1nm.
>>>>>
>>>>> So not much difference in size at all.
>>>> Dear Ben,
>>>>
>>>> The size of the molecules is as irrelevant as the quibbling.
>>>>
>>>> The larger CO2 molecule escapes through butyl rubber at about ten
>>>> times the rate of the obviously smaller O2 molecule:
>>> What are the transfer rates through butyl rubber at various
>>> pressures < 8 bar for
>>>
>>> 1) H2
>>> 2) He
>>> 3) CO2
>> Why not look up the answers and tell us something?
>
> It is your proposition. I am not here to do
> your work for you.

you goddamned hypocrite!!!!!!!!!!!!


>
>> The links have been posted several times.
>
> The discussion had been about H2 and He.
> You brought the transport rate of CO2.
> I propose that you provide the data.
> You and jim beam want others to do
> your and jim beam's research.
> You have a proposition? Prove it.
>
> What are the transfer rates through butyl rubber at various
> pressures < 8 bar for
> 1) H2
> 2) He
> 3) CO2
>

 

[jim beam]

Michael Press wrote:
<snip ****>

poor wittle mikey wikey - he's upset that his wittle games are so
transparent that the other children won't play...

 

[Marian]

On Nov 1, 3:20 am, [email protected] wrote:
> Carl Fogel writes:
> >>> A rubber inner-tube filled with water, on the other hand, is going to
> >>> be squishing a lot of water around as it rolls, and the mass of the
> >>> water will be swirling uselessly, so there will be more drag.
> >> The two times I had to do this, I cannot say I noticed any
> >> difference in drag. Or otherwise. This was on the Moulton, which
> >> has full suspension, so that would have masked some of the effects.
> > Interesting--I just fooled around with a calculator a bit to see
> > what the practical effect might be.
> > Even a large increase in rolling resistance will barely show up in
> > the top speed recorded coasting downhill on a good cyclocomputer,
> > according to this calculator:
>
> http://austinimage.com/bp/velocityN/velocity.html
>
> > If you zero watts and roll both bikes down the same -6% grade, they
> > reach 53.775 km/h.
> > Raise the rolling resistance 50% from 0.0050 to 0.0075, and the bike
> > with squashier tires drops to 52.539 km/h, only 1.236 km/h slower,
> > about a 2% speed change. In other words, the top coasting speed
> > would drop to 28.37 mph from 29.04 mph, a difference that no one is
> > likely to notice without the help of microchips.
> > For a 10% speed change down that hill, you need to raise the rolling
> > resistance to about three times the original 0.0050, up to about
> > 0.0150--and that's still just dropping about 3 mph from about 30
> > mph.
> > I'm trying to resist the urge to fill a spare front wheel with water
> > and roll down my daily highway descent a few times.
>
> When you do that, make sure to let all the air out as the tire gets
> near full. With the valve at the top and press down on the tire flat
> against the inflation stem so there is no higher space for the air to
> rise above the water. Pushing down on the WHEEL in this position
> should ultimately squirt only water out of the Presta valve. Then
> fill the tire the rest of the way to full.
>
> I used my Silca frame fit pump for that task because it is easy to
> fill with water and has a large enough volume to make it a relatively
> quick job. It doesn't take nearly as many strokes as filling the tire
> with air.

Okay now that you've told us how...

Why?

(Whether or not it happens to be the truth "because" and "I wanted to
see what would happen" are not valid answers.)

-M

 

[Aeek]

On Fri, 02 Nov 2007 10:21:06 -0000, Marian
<[email protected]> wrote:

>Why?
>
>(Whether or not it happens to be the truth "because" and "I wanted to
>see what would happen" are not valid answers.)

for the fish!

 

[datakoll]

nitrogen is used caws it's dry - H20 cawses imbalance, higher friction.

 

[[email protected]]

On Fri, 02 Nov 2007 10:21:06 -0000, Marian
<[email protected]> wrote:

>On Nov 1, 3:20 am, [email protected] wrote:
>> Carl Fogel writes:

[snip]

>> > I'm trying to resist the urge to fill a spare front wheel with water
>> > and roll down my daily highway descent a few times.
>>
>> When you do that, make sure to let all the air out as the tire gets
>> near full. With the valve at the top and press down on the tire flat
>> against the inflation stem so there is no higher space for the air to
>> rise above the water. Pushing down on the WHEEL in this position
>> should ultimately squirt only water out of the Presta valve. Then
>> fill the tire the rest of the way to full.
>>
>> I used my Silca frame fit pump for that task because it is easy to
>> fill with water and has a large enough volume to make it a relatively
>> quick job. It doesn't take nearly as many strokes as filling the tire
>> with air.
>
>Okay now that you've told us how...
>
>Why?
>
>(Whether or not it happens to be the truth "because" and "I wanted to
>see what would happen" are not valid answers.)
>
>-M

Dear Marian,

Jobst once had no spare and a pinhole leak in a tubular. The tire went
flat in a few minutes, so he filled the tube with water from a creek
and was able to finish his ride before the water leaked out:

http://groups.google.com/group/rec.bicycles.tech/msg/a336cc675d115c0c

Water is much more viscous than air, so it takes far longer to leak
out through the tiny hole--imagine trying to empty a 32-ounce water
bottle (roughly the volume of a tubular) through a pinhole.

Cheers,

Carl Fogel

 

[datakoll]

whaddya mean "far longer" 9 months? 12 minutes? 35 seconds?

 

[Tom Sherman]

datakoll aka gene daniels wrote:
>
> whaddya mean "far longer" 9 months? 12 minutes? 35 seconds?
>
Four (4) minutes, thirty-three (33) seconds.

--
Tom Sherman - Holstein-Friesland Bovinia
When did ignorance of biology become a "family value"?

 

[[email protected]]

Just figured the connection between flat tires and the guy arrested
for having sex with his bike. He was just trying to create a home grown
leak sealant. Hope his bike doesn't have Presta tubes !!!

 

[[email protected]]

Just figured the connection between flat tires and the guy arrested
for having sex with his bike. He was just trying to create a home grown
leak sealant. Hope his bike doesn't have Presta tubes !!!