3 Punctures in 3 Consecutive Days?

How can this be happening? Widdershins, my beautiful recumbent trike,
has suffered three punctures on three consecutive riding days.

They are all on the same, right-front wheel, on the outer side of the
tube: tiny holes that look like pinpricks. I have thoroughly checked
the inside of the tyre for any protrusions or anomalies, and all is
smooth. There is a small hole in the tyre, barely sufficient to let a
grain of sand or something like that through.

There was another puncture like these about a month ago. I think it
was on the same wheel but it could have been the other front wheel. On
that occasion, I changed the inner tube for a new one. The second
occasion, I was using a patched tube (but the hole did not recur where
the patch was), and today I was using a brand new tube again, on its
first outing.

The trip to work takes over a very nasty dirt path, and in this season
there is a lot of slippery vegetation on the road, including
quantities of thorny horse-chestnuts. But the timing of the deflation
does not invariably coincide with my going over the path. One time it
happened just as I was arriving at work; then just after I left my
home in the morning, then today I arrived fine but when I went out to
lunch found the tyre flat again.

The bike is left on the company parking lot in the daytime. I really,
really would like to rule out deliberate sabotage (there is one person
in particular who has acted in similar ways in the past). How long
would a tube take to deflate through a very small hole? It would be so
easy, so anonymous, so untraceable, discretely to puncture a tyre on a
bike on a parking lot with a brooch pin. But since I have actually
ridden the bike for a full 10 km trip from the parking lot before the
wheel has gone flat, I'm curious if it could be ridden on for that
long without the puncture declaring itself.

This series of flats is distinct from the nine successive flats that I
had on my folding Dahon, that were all on the inside of the tube,
towards the rim rather than the road. Those were being caused by a
badly designed wheel and indirectly, by the spokes. So alas, I cannot
use any of my old science on this new case.

Over the weekend I will try to change the tyre. Even if I can't find
the problem, changing a tyre has inexplicably helped in the past.
Perhaps it is no longer entire enough to prevent grit from getting
between it and the tube.

Expert thoughts of the group welcome. Thanks,

EFR
Ile de France

Artemisia writes:

How can this be happening? Widdershins, my beautiful recumbent trike,
has suffered three punctures on three consecutive riding days.

They are all on the same, right-front wheel, on the outer side of the
tube: tiny holes that look like pinpricks. I have thoroughly checked
the inside of the tyre for any protrusions or anomalies, and all is
smooth. There is a small hole in the tyre, barely sufficient to let a
grain of sand or something like that through.

A tiny hole when the tyre is off may become large enough under pressure
to allow a bubble of tube to stick out. A big bubble will probably pop
(and soon) and show a small tear in the tube, but a small bubble may
last a while until something abrades it.

Brendan
--
Brendan Halpin, Department of Sociology, University of Limerick, Ireland
Tel: w +353-61-213147 f +353-61-202569 h +353-61-338562; Room F2-025 x 3147
http://www.ul.ie/sociology/brendan.halpin.html

Artemisia wrote:
How can this be happening? Widdershins, my beautiful recumbent trike,
has suffered three punctures on three consecutive riding days.


One suggestion - when you refit your tyre, make sure you do it in a
known position (e.g. the start of manufacturer's name printed on the
tyre lining up with the valve). That way, when you get a puncture you
will know exactly where on the tyre the puncture came from as you can
line up the tube's valve with the printing on the tyre.

That is very useful for finding bits of thorn, etc., that may be stuck
in the tyre as you know exactly where to look once you've found the hole
in the tube. If you find nothing but puncture again in the same place
(you'll know it is the same place as you'll have put the tyre back on
exactly as it came off) then you know there is a problem with the tyre.

Alternatively, it may also be useful to know that the punctures are
happening at random places - which would suggest either tyres that are
worn/not sufficiently puncture resistant for your route, or sabotage.

Matt

Artemisia wrote:

The bike is left on the company parking lot in the daytime. I really,
really would like to rule out deliberate sabotage (there is one person
in particular who has acted in similar ways in the past). How long
would a tube take to deflate through a very small hole?

Several hours is quite possible.

Tyres do become prone to punctures when they get old (happened to my
Streetmachine front earlier this year), but we're talking many, many
thousands of km and usually a few years.

Check the outside of the tyre thoroughly as well as the inside: you can
have something lodged in which needs high pressure and weight to bother
the tube but which isn't picked up on a straight inspection of the inside.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

Artemisia wrote:
How can this be happening? Widdershins, my beautiful recumbent trike,
has suffered three punctures on three consecutive riding days.

They are all on the same, right-front wheel, on the outer side of the
tube: tiny holes that look like pinpricks. I have thoroughly checked
the inside of the tyre for any protrusions or anomalies, and all is
smooth. There is a small hole in the tyre, barely sufficient to let a
grain of sand or something like that through.

Once I did a particularly bad road, with many small stones and lots of dirt.
Next day a flat: I found nothing in the tire and nothing between tire and inner
tube (but it was raining quite hard and I was a bit in a hurry). Shortly after a
new flat: again nothing evident, but... I did put the tire in a know position
(label above the valve and on the right), so I started looking carefully around
the region of the puncture. After a few tries I could find a minuscule piece of
stone embedded in the tire and barely sticking inside (I had to fold the tire to
feel it). This stone chip obviously worked its way all the way through the wall
until it reached the inner tube and then...

Mount the tire in a know position, wait for the next flat (if any) and then
match puncture and tire.

Ciao,
--
Roberto Divia` Love at first sight is one of the greatest
Dep:PH Bat:53 Mailbox:C02110 labour-saving devices the world has ever seen
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On Fri, 10 Oct 2008 05:51:00 -0700 (PDT)
Artemisia wrote:

How can this be happening? Widdershins, my beautiful recumbent trike,
has suffered three punctures on three consecutive riding days.

They are all on the same, right-front wheel, on the outer side of the
tube: tiny holes that look like pinpricks. I have thoroughly checked
the inside of the tyre for any protrusions or anomalies, and all is
smooth. There is a small hole in the tyre, barely sufficient to let a
grain of sand or something like that through.

While there's nothing obviously sticking through, there could be a
bit of thorn or quartz embedded - I usually poke an old spoke through
the hole to make sure there's nothing lurking, although for
small holes something like a broken sewing machine needle might be
better (just thought of that - make note to save a broken sewing
machine needle).

The trip to work takes over a very nasty dirt path, and in this season
there is a lot of slippery vegetation on the road, including
quantities of thorny horse-chestnuts.

So what's a horse-chestnut? Is that a goathead like we get in NM/TX ?
http://en.wikipedia.org/wiki/Goathead

rms

rms wrote:

So what's a horse-chestnut? Is that a goathead like we get in NM/TX ?
http://en.wikipedia.org/wiki/Goathead

Horse-chestnuts are better known as conkers in the UK. The pic of the
nut at http://en.wikipedia.org/wiki/Conkers shows the problem points.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

rms wrote:

The trip to work takes over a very nasty dirt path, and in this season
there is a lot of slippery vegetation on the road, including
quantities of thorny horse-chestnuts.

So what's a horse-chestnut? Is that a goathead like we get in NM/TX ?
http://en.wikipedia.org/wiki/Goathead

Conkers.

A horse chestnut is a great big tree with spiky fruit capsules.

http://www.woodlands-junior.kent.sch...s/conkers.html
--
Phil Cook looking north over the park to the "Westminster Gasworks"

On Fri, 10 Oct 2008 09:00:28 -0600
"rms" wrote:

The trip to work takes over a very nasty dirt path, and in this
season there is a lot of slippery vegetation on the road, including
quantities of thorny horse-chestnuts.

So what's a horse-chestnut? Is that a goathead like we get in
NM/TX ? http://en.wikipedia.org/wiki/Goathead

Nothing like. Why didn't you ask Wikipedia?

http://en.wikipedia.org/wiki/Image:A...anum_fruit.jpg