Avoiding patching a tube (anatomy of a flat)

Lots of posts on patching tubes lately. So, I did something last
weekend to try to avoid the need. I've noticed in the past that the
apparent cause of most of my flats is small pieces of glass that
aren't big enough to stick all the way in from the outside. Unlike a
nail, which I suppose can just go right from the outside into a tube,
these pieces of glass seem to work their way in over time, getting
deeper and deeper as the tire bangs and bounces along the road until
it finally nicks the tube. They seem to do a good job gouging a
crevice in the tire.

I deflated the tires and stuck a sharp pointy thing into the various
cracks and crevices in the tires, prying out little bits of stuff
stuck in them. I took care to avoid puncturing the tube in the
process. One tire I removed and went around it feeling for anything
inside. I decided I didn't need to remove the other tire, just deflate
it.

Two of these cracks contained sizeable pieces of glass that were
clearly working their way deeper. I don't know that these would have
produced flats, but I suspect they would do so. Neither had broken
through the tire but both were quite deep.

So, I suspect that I've just avoided two flats by removing the
offending glass before it did the dirty work. Maybe it woudl be a good
idea to do this every other month or so?

In article ,
dgk writes:
Lots of posts on patching tubes lately. So, I did something last
weekend to try to avoid the need. I've noticed in the past that the
apparent cause of most of my flats is small pieces of glass that
aren't big enough to stick all the way in from the outside. Unlike a
nail, which I suppose can just go right from the outside into a tube,
these pieces of glass seem to work their way in over time, getting
deeper and deeper as the tire bangs and bounces along the road until
it finally nicks the tube. They seem to do a good job gouging a
crevice in the tire.

I deflated the tires and stuck a sharp pointy thing into the various
cracks and crevices in the tires, prying out little bits of stuff
stuck in them. I took care to avoid puncturing the tube in the
process. One tire I removed and went around it feeling for anything
inside. I decided I didn't need to remove the other tire, just deflate
it.

Two of these cracks contained sizeable pieces of glass that were
clearly working their way deeper. I don't know that these would have
produced flats, but I suspect they would do so. Neither had broken
through the tire but both were quite deep.

So, I suspect that I've just avoided two flats by removing the
offending glass before it did the dirty work. Maybe it woudl be a good
idea to do this every other month or so?

In my own purposes, it's just not worth getting
one's hands dirty for.

Tires are disposable/replacable commodities; they
inevitably wear out or otherwise become unusable.
The answer is to just replace 'em as needed.

I've found the best way for me to prolong my tires'
lives is to simply watch where I'm riding, and
avoid rolling over sharp debris on the road.

Less time on the sidewalks (walking, of course)
helps too. Sidewalks can be rife with broken glass.

I too have wondered about embedded particles being
gradually forced through tire rubber, to attack the
tube like parasitic worms, but I opinionatedly doubt
that possibility. The tire casing is a pretty tough
membrane, and I think it would be quite difficult for
a slow-moving particle to eventually penetrate it.
By the time that happens, one would have worn the tire
out anyway. To the best of my knowledge, tire casings
are always penetrated with a quick, forceful stab with
a sharp object that's long enough to go through outer
rubber and interior casing in one decisive, fatal go.
Like a goathead thorn.


cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

On Mon, 27 Apr 2009 13:40:43 -0700, (Tom Keats)
wrote:

To the best of my knowledge, tire casings
are always penetrated with a quick, forceful stab with
a sharp object that's long enough to go through outer
rubber and interior casing in one decisive, fatal go.
Like a goathead thorn.

But not in wet conditions. On a dry tire the force of the wheel
spinning will generally throw off debris before it can puncture and
start worming it's way in. However, a wet tire will hold on to said
debris and allow it to penetrate further with every roll.

I'd say over 80% of my flats are dluring wet conditions.

On Mon, 27 Apr 2009 13:40:43 -0700, (Tom Keats)
wrote:

In article ,
dgk writes:
Lots of posts on patching tubes lately. So, I did something last
weekend to try to avoid the need. I've noticed in the past that the
apparent cause of most of my flats is small pieces of glass that
aren't big enough to stick all the way in from the outside. Unlike a
nail, which I suppose can just go right from the outside into a tube,
these pieces of glass seem to work their way in over time, getting
deeper and deeper as the tire bangs and bounces along the road until
it finally nicks the tube. They seem to do a good job gouging a
crevice in the tire.

I deflated the tires and stuck a sharp pointy thing into the various
cracks and crevices in the tires, prying out little bits of stuff
stuck in them. I took care to avoid puncturing the tube in the
process. One tire I removed and went around it feeling for anything
inside. I decided I didn't need to remove the other tire, just deflate
it.

Two of these cracks contained sizeable pieces of glass that were
clearly working their way deeper. I don't know that these would have
produced flats, but I suspect they would do so. Neither had broken
through the tire but both were quite deep.

So, I suspect that I've just avoided two flats by removing the
offending glass before it did the dirty work. Maybe it woudl be a good
idea to do this every other month or so?

In my own purposes, it's just not worth getting
one's hands dirty for.

Tires are disposable/replacable commodities; they
inevitably wear out or otherwise become unusable.
The answer is to just replace 'em as needed.

I've found the best way for me to prolong my tires'
lives is to simply watch where I'm riding, and
avoid rolling over sharp debris on the road.

Less time on the sidewalks (walking, of course)
helps too. Sidewalks can be rife with broken glass.

I too have wondered about embedded particles being
gradually forced through tire rubber, to attack the
tube like parasitic worms, but I opinionatedly doubt
that possibility. The tire casing is a pretty tough
membrane, and I think it would be quite difficult for
a slow-moving particle to eventually penetrate it.
By the time that happens, one would have worn the tire
out anyway. To the best of my knowledge, tire casings
are always penetrated with a quick, forceful stab with
a sharp object that's long enough to go through outer
rubber and interior casing in one decisive, fatal go.
Like a goathead thorn.




Not in my experience. I've very rarely had something like a nail go
through a tire, and we don't have goatheads here (murders, taxis,
joggers, yes, goatheads no).

If something penetrated the tire in one quick shot, wouldn't it stay
in the tire? It takes a lot of force to push through.

After each flat, I feel around the inside of the tire for anything I
can feel. Very rarely do I find something. Usually, when I inspect
around the tire, I find a little piece of glass in a crevice. That
piece of glass is generally just what I took out of the tires over the
weekend, but they made it through. I'll have to more closely match up
the tube to the tire next time. I usually don't even patch the tire
then; I just put in a new tube and fix the old tube when I get home.

Right now, with the trees dropping those little pretty petals
everywhere, it's really tough to tell them apart from glass. It all
just looks like little shiny things so it's very tough to avoid glass.

On Mon, 27 Apr 2009 21:52:33 -0500, Mr. Smith
wrote:

On Mon, 27 Apr 2009 13:40:43 -0700, (Tom Keats)
wrote:

To the best of my knowledge, tire casings
are always penetrated with a quick, forceful stab with
a sharp object that's long enough to go through outer
rubber and interior casing in one decisive, fatal go.
Like a goathead thorn.

But not in wet conditions. On a dry tire the force of the wheel
spinning will generally throw off debris before it can puncture and
start worming it's way in. However, a wet tire will hold on to said
debris and allow it to penetrate further with every roll.

I'd say over 80% of my flats are dluring wet conditions.

Yes, I've also found that wet conditions are much more conducive to
flats. But not always the wet day. I seem to get flats a few days
later. Needs more study.

On Apr 27, 9:29*am, dgk wrote:
Lots of posts on patching tubes lately. So, I did something last
weekend to try to avoid the need. I've noticed in the past that the
apparent cause of most of my flats is small pieces of glass that
aren't big enough to stick all the way in from the outside. Unlike a
nail, which I suppose can just go right from the outside into a tube,
these pieces of glass seem to work their way in over time, getting
deeper and deeper as the tire bangs and bounces along the road until
it finally nicks the tube. They seem to do a good job gouging a
crevice in the tire.

I deflated the tires and stuck a sharp pointy thing into the various
cracks and crevices in the tires, prying out little bits of stuff
stuck in them. I took care to avoid puncturing the tube in the
process. One tire I removed and went around it feeling for anything
inside. I decided I didn't need to remove the other tire, just deflate
it.

Two of these cracks contained sizeable pieces of glass that were
clearly working their way deeper. I don't know that these would have
produced flats, but I suspect they would do so. Neither had broken
through the tire but both were quite deep.

So, I suspect that I've just avoided two flats by removing the
offending glass before it did the dirty work. Maybe it woudl be a good
idea to do this every other month or so?

I guess I've got nothing to lose by giving my tires a little visual
inspection before rides, but deflating them might be a bit much. Of
course some tires are much more flat prone than others. Right now I'm
running some Conti's that seem to flat at the drop of a hat. A thorn
resistant tube seems has helped, but it does weigh more so some folks
might not want to use one.

Eric

On Apr 27, 8:29*am, dgk wrote:
So, I suspect that I've just avoided two flats by removing the
offending glass before it did the dirty work. Maybe it woudl be a good
idea to do this every other month or so?

Yes, it really does help to do this regularly. Also you don't
absolutely need to deflate the tire (though perhaps it helps).

I can think of maybe two flats I've had over the years from something
like a nail (once an actual nail, another a thumbtack)--compared with
dozens from the little bits of glass and sharp little shards of rock &
the like.

Some people swear by a little gadget that sort of lightly rides over
the top of your tire and sweeps off bits of glass & the like before
they have the chance to become embedded. You could make something
like this from a bent bit of wire if you can't find the commercially
available ones.

In article ,
dgk writes:

I too have wondered about embedded particles being
gradually forced through tire rubber, to attack the
tube like parasitic worms, but I opinionatedly doubt
that possibility. The tire casing is a pretty tough
membrane, and I think it would be quite difficult for
a slow-moving particle to eventually penetrate it.
By the time that happens, one would have worn the tire
out anyway. To the best of my knowledge, tire casings
are always penetrated with a quick, forceful stab with
a sharp object that's long enough to go through outer
rubber and interior casing in one decisive, fatal go.
Like a goathead thorn.

Not in my experience. I've very rarely had something like a nail go
through a tire, and we don't have goatheads here (murders, taxis,
joggers, yes, goatheads no).

If something penetrated the tire in one quick shot, wouldn't it stay
in the tire?

Yup. Then you've gotta pull it out from the outside,
often with the use of a pair of pliers.

It takes a lot of force to push through.

A rider's weight helps. And then the FAQ talks of the
front wheel setting stuff like wayward nails up to be
run-over by the rear wheel.

After each flat, I feel around the inside of the tire for anything I
can feel. Very rarely do I find something. Usually, when I inspect
around the tire, I find a little piece of glass in a crevice. That
piece of glass is generally just what I took out of the tires over the
weekend, but they made it through. I'll have to more closely match up
the tube to the tire next time. I usually don't even patch the tire
then; I just put in a new tube and fix the old tube when I get home.

Y'know, yer right.

My last several flats where perpetuated by larger
sharp objects that I could pull out of the tire
from the outside.

But now that I think about it, I've gone through
many tire replacements because too-hard-to-see
stuff was causing too-frequent punctures.

I can visualize two factors at work to cause that:

1) an initial particle gets imbedded in the tire,
and subsequent particles drive the initial
particle further in as those particles stack up
against each other in the same vulnerable hole
in the tire.

2) lazily letting tire pressure get a little low
(I'm as guilty as anybody for that) so the tire
squashes down a little more around the particle
each time it rolls over something that pushes
the tire toward the rim. Especially when riding
rear wheels off of curbs.

Right now, with the trees dropping those little pretty petals
everywhere, it's really tough to tell them apart from glass. It all
just looks like little shiny things so it's very tough to avoid glass.

It's cheery cherry blossom time here, too.

I generally like to match-up the inflation rating on the
tire, the inner tube valve, and the rim's valve hole
all in one place when mounting a tire.

So, if I dementially forget how hard to air up my tires,
I might remember where to look. And my floor pump has
this adjustable ring on it, with a black mark I don't
even need reading glasses to see. All I've gotta do
is pump the gauge's needle up to the black arrow.
As long as nobody messes with the adjustable ring.

I used to be able to read the date on a dime with
my naked eye.

Oh, well.


cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

In article ,
(Tom Keats) writes:

I generally like to match-up the inflation rating on the
tire, the inner tube valve, and the rim's valve hole
all in one place when mounting a tire.

I know it's hard to mis-match valve and valve-hole.

But I've achieved all kinds of monstrosities by
working in the dark + a li'l guesswork.


cheers again,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

On Thu, 30 Apr 2009 16:16:45 -0700 (PDT), Brent Hugh
wrote:

On Apr 27, 8:29*am, dgk wrote:
So, I suspect that I've just avoided two flats by removing the
offending glass before it did the dirty work. Maybe it woudl be a good
idea to do this every other month or so?

Yes, it really does help to do this regularly. Also you don't
absolutely need to deflate the tire (though perhaps it helps).


I only deflated the tires because I figured that sticking a pointy
thing into the tire (to remove the debris) might nick the tube if it
was inflated. If it makes contact with a deflated tube it should just
push it away.

I'm using the Schwalbe Marathon Plus tires. They really are very flat
resistant, but I pay for it with rolling resistance. Resistance causes
resistance apparently.