Innertube Porosity?

On 9/3/2017 11:43 PM, John B. wrote:
On Sun, 3 Sep 2017 11:47:28 -0000 (UTC), Duane wrote:

John B. wrote:
On Sat, 2 Sep 2017 11:34:53 -0700 (PDT), wrote:

On Friday, September 1, 2017 at 7:42:16 PM UTC-7, John B. wrote:
On Fri, 1 Sep 2017 06:52:47 -0700 (PDT), wrote:

On Thursday, August 31, 2017 at 7:59:06 PM UTC-7, John B. wrote:
On Thu, 31 Aug 2017 06:48:22 -0700 (PDT), wrote:

On Thursday, August 31, 2017 at 2:51:25 AM UTC-7, Duane wrote:
James wrote:
On 31/08/17 03:39, wrote:
On Tuesday, August 29, 2017 at 5:56:52 PM UTC-7, James wrote:
On 30/08/17 01:55, wrote:
On Tuesday, August 29, 2017 at 1:52:10 AM UTC-7,
wrote:
Remove the valve, inject a very strong sugar/water solution,
replace dust cap, spin the wheel to distribute the solution
inside the tube, drain the solution as much as possible,
replace valve and inflate.

All you have to do is use latex tubes. These have so low a
porosity that you only have to pump up your tires slightly one
day a week after the initial settling in period.


Which latex tubes have low porosity? Ones I've tried meant pumping
up tyres every couple of days. Regular butyl tubes stay inflated
much longer for me.

The cheapest one's available - Vitorria.

I have NEVER had a butyl tube that didn't require pumping before
every single ride and I ride four times a week or more. On my 23 mm
tires they lose 20-30 lbs from one day to the next depending upon
temperature and how difficult the ride was (which can heat the
tires.)


Absolutely no way my 23mm or 25mm tyres with butyl inner tubes lose
anywhere near that much pressure after one day, starting from near 100psi.


I pump my tires before mostly every ride out of habit. I don't see the
issue with this. Takes 5 minutes.

Anyway, I run them at 95-100psi and if they lose more than 5 or 10 psi in a
day, I would suspect a slow leak.

I have to run 120 psi and they drop to less than 90 from one ride to
the next - generally two days.

After installing the Vittoria latex tubes - after a week I'm not losing any pressure.

Do you happen to remember the actual name of the inner tubes? Vittoria
makes several grades/names of tubes and I would like to get a set of
whatever you are using.

Vittoria Ultra Light Inner Tube. I bought them because they had the
correct stem length for my new wheels.

Thanks for that. I shall buy a set next time I'm by the bike shop.
--
Cheers,

John B.

James made the point that he didn't see any big deal with pumping his
tires before a ride. Neither do I. That's why I was pleasantly surprised
when I didn't have to pump my tires up. I have used every kind of inner
tube and never had one that didn't need pumping between rides. On the
fat tire bikes I would overfill it a little so that I didn't need to
pump it two days later and it would only be a little under pressure.

The tubes I'm presently using will lose about 10 psi, from 100 psi, in
a 24 hour period and as I can't fit larger tires due to space I am
using 25mm tires. Many of the older Bangkok streets are bumpy so I use
80 psi which is pretty much the lowest that I can use and be
reasonably assured not to have pinch flats. Or too many of them,
anyway :-)

So, I can either pump the tires up more and enjoy bumpier rides or
pump them every time I ride.

As I am getting lazy in my old age I am getting tired of pumping tires
every day. Just think of it, if I only have to pump the tires every
two days that is a 50% decrease.

The 26" X 1.5" tires on my "knock about" bike in Phuket only require
pumping about one a week :-)
--
Cheers,


23mm tires on HED 23mm rims let me run them at 90 psi without pinch flats.
Montreal roads are awful so this made a big difference for me. The tubes
don't seem to lose air as quickly as Tom is saying but the lower pressure
may have something to do with that.

I would suspect so as volume of flow through a pipe is determined by
the pressure and I would assume that it would be similar through a
porous tube.

And I would assume that volume also effects things as a loss of 1
sq.in. of volume from a one square inch chamber is quite different
then losing the same volume from a 100 inch chamber :=)

Yep. I'd expect that the rate of pressure decrease is proportional to
pressure and inversely proportional to volume. I bet this can be readily
worked out by those who are into mathematical recreation.

Where have those guys gone?

--
- Frank Krygowski

On Mon, 4 Sep 2017 10:56:08 -0400, Frank Krygowski
wrote:

On 9/3/2017 11:43 PM, John B. wrote:
On Sun, 3 Sep 2017 11:47:28 -0000 (UTC), Duane wrote:

John B. wrote:
On Sat, 2 Sep 2017 11:34:53 -0700 (PDT), wrote:

On Friday, September 1, 2017 at 7:42:16 PM UTC-7, John B. wrote:
On Fri, 1 Sep 2017 06:52:47 -0700 (PDT), wrote:

On Thursday, August 31, 2017 at 7:59:06 PM UTC-7, John B. wrote:
On Thu, 31 Aug 2017 06:48:22 -0700 (PDT), wrote:

On Thursday, August 31, 2017 at 2:51:25 AM UTC-7, Duane wrote:
James wrote:
On 31/08/17 03:39, wrote:
On Tuesday, August 29, 2017 at 5:56:52 PM UTC-7, James wrote:
On 30/08/17 01:55, wrote:
On Tuesday, August 29, 2017 at 1:52:10 AM UTC-7,
wrote:
Remove the valve, inject a very strong sugar/water solution,
replace dust cap, spin the wheel to distribute the solution
inside the tube, drain the solution as much as possible,
replace valve and inflate.

All you have to do is use latex tubes. These have so low a
porosity that you only have to pump up your tires slightly one
day a week after the initial settling in period.


Which latex tubes have low porosity? Ones I've tried meant pumping
up tyres every couple of days. Regular butyl tubes stay inflated
much longer for me.

The cheapest one's available - Vitorria.

I have NEVER had a butyl tube that didn't require pumping before
every single ride and I ride four times a week or more. On my 23 mm
tires they lose 20-30 lbs from one day to the next depending upon
temperature and how difficult the ride was (which can heat the
tires.)


Absolutely no way my 23mm or 25mm tyres with butyl inner tubes lose
anywhere near that much pressure after one day, starting from near 100psi.


I pump my tires before mostly every ride out of habit. I don't see the
issue with this. Takes 5 minutes.

Anyway, I run them at 95-100psi and if they lose more than 5 or 10 psi in a
day, I would suspect a slow leak.

I have to run 120 psi and they drop to less than 90 from one ride to
the next - generally two days.

After installing the Vittoria latex tubes - after a week I'm not losing any pressure.

Do you happen to remember the actual name of the inner tubes? Vittoria
makes several grades/names of tubes and I would like to get a set of
whatever you are using.

Vittoria Ultra Light Inner Tube. I bought them because they had the
correct stem length for my new wheels.

Thanks for that. I shall buy a set next time I'm by the bike shop.
--
Cheers,

John B.

James made the point that he didn't see any big deal with pumping his
tires before a ride. Neither do I. That's why I was pleasantly surprised
when I didn't have to pump my tires up. I have used every kind of inner
tube and never had one that didn't need pumping between rides. On the
fat tire bikes I would overfill it a little so that I didn't need to
pump it two days later and it would only be a little under pressure.

The tubes I'm presently using will lose about 10 psi, from 100 psi, in
a 24 hour period and as I can't fit larger tires due to space I am
using 25mm tires. Many of the older Bangkok streets are bumpy so I use
80 psi which is pretty much the lowest that I can use and be
reasonably assured not to have pinch flats. Or too many of them,
anyway :-)

So, I can either pump the tires up more and enjoy bumpier rides or
pump them every time I ride.

As I am getting lazy in my old age I am getting tired of pumping tires
every day. Just think of it, if I only have to pump the tires every
two days that is a 50% decrease.

The 26" X 1.5" tires on my "knock about" bike in Phuket only require
pumping about one a week :-)
--
Cheers,


23mm tires on HED 23mm rims let me run them at 90 psi without pinch flats.
Montreal roads are awful so this made a big difference for me. The tubes
don't seem to lose air as quickly as Tom is saying but the lower pressure
may have something to do with that.

I would suspect so as volume of flow through a pipe is determined by
the pressure and I would assume that it would be similar through a
porous tube.

And I would assume that volume also effects things as a loss of 1
sq.in. of volume from a one square inch chamber is quite different
then losing the same volume from a 100 inch chamber :=)

Yep. I'd expect that the rate of pressure decrease is proportional to
pressure and inversely proportional to volume. I bet this can be readily
worked out by those who are into mathematical recreation.

Naaa, really? Or are youse just funnin us Mr. Frank?

(Hot Dam! What'ly they think of next?)

Where have those guys gone?
--
Cheers,

John B.

On Friday, September 1, 2017 at 4:21:53 PM UTC-7, wrote:
On Friday, September 1, 2017 at 2:37:05 PM UTC-7, Sir Ridesalot wrote:
On Friday, September 1, 2017 at 1:25:25 PM UTC-4, wrote:
On Friday, September 1, 2017 at 7:13:49 AM UTC-7, Sir Ridesalot wrote:
On Friday, September 1, 2017 at 9:52:50 AM UTC-4, wrote:
On Thursday, August 31, 2017 at 7:59:06 PM UTC-7, John B. wrote:
On Thu, 31 Aug 2017 06:48:22 -0700 (PDT), wrote:

On Thursday, August 31, 2017 at 2:51:25 AM UTC-7, Duane wrote:
James wrote:
On 31/08/17 03:39, wrote:
On Tuesday, August 29, 2017 at 5:56:52 PM UTC-7, James wrote:
On 30/08/17 01:55, wrote:
On Tuesday, August 29, 2017 at 1:52:10 AM UTC-7,
wrote:
Remove the valve, inject a very strong sugar/water solution,
replace dust cap, spin the wheel to distribute the solution
inside the tube, drain the solution as much as possible,
replace valve and inflate.

All you have to do is use latex tubes. These have so low a
porosity that you only have to pump up your tires slightly one
day a week after the initial settling in period.


Which latex tubes have low porosity? Ones I've tried meant pumping
up tyres every couple of days. Regular butyl tubes stay inflated
much longer for me.

The cheapest one's available - Vitorria.

I have NEVER had a butyl tube that didn't require pumping before
every single ride and I ride four times a week or more. On my 23 mm
tires they lose 20-30 lbs from one day to the next depending upon
temperature and how difficult the ride was (which can heat the
tires.)


Absolutely no way my 23mm or 25mm tyres with butyl inner tubes lose
anywhere near that much pressure after one day, starting from near 100psi.


I pump my tires before mostly every ride out of habit. I don't see the
issue with this. Takes 5 minutes.

Anyway, I run them at 95-100psi and if they lose more than 5 or 10 psi in a
day, I would suspect a slow leak.

I have to run 120 psi and they drop to less than 90 from one ride to the next - generally two days.

After installing the Vittoria latex tubes - after a week I'm not losing any pressure.

Do you happen to remember the actual name of the inner tubes? Vittoria
makes several grades/names of tubes and I would like to get a set of
whatever you are using.

Vittoria Ultra Light Inner Tube. I bought them because they had the correct stem length for my new wheels.

Um, I just checked a number of sites and they all say those tubes are BUTYL.

https://www.competitivecyclist.com/v...ultralite-tube

Lightweight, high-quality butyl rubber means you get the performance and pinch-flat resistance of latex with superior air retention to latex. Available in your choice of valve length: 42mm or 51mm. 84g.

https://www.ribblecycles.co.uk/vitto...ltralite-tube/
Vittoria Butyl Ultralite Tube

Are you SURE your tubes aren't butyl?

I've never seen pink butyl tubes. Also they are advertised as: "Vittoria Latex Road Inner Tube"

I have given my experience. I didn't have to do this. It was for the group's information. So far a lot of you have called me a liar. I'll mark that down for future reference when I find something that is a superior product.

I did NOT call you a liar. You said that the tubes we "Vittoria Ultra Light Inner Tube" and my searchesall came up as them being made of Butyl NOT latex. Now you've posted an entirely different designation for the tubes you're using.

Cheers

Looking it up on Vitorria's site I read this: "We recommend to use a Pit Stop Road Racing cartridge or a liquid latex to be injected into the valve core with a syringe after removing the core itself. It seals the typical porosity of the latex walls, preventing annoying inflation pressure loss and adding the puncture prevention feature that the liquid latex uses to guarantee."

I wonder if these tubes come with the additional latex injected. As I said, first they seemed to lose air just like the butyl tubes but after a week that all stopped.

sugar water sounds cheaper