Pinch puncture?

Marco said:

Hi

What is a "pinch-puncture" and how do you avoid them?

I've had several punctures lately, for no apparent reason (nothing
poking thru the tyre) so I think I may be getting pinch-punctures but
don't know what they are or what to do about them!

A pinch puncture (aka snake bite[1]) is when the wheel rim bottoms out
onto the tyre pinching the inner tube.
If you ride totally on road you should never get these, and if you do
your tyres are not pumped up enough.

Off road, again, you need to pump up your tyres more. These can occur a
lot off road if you are deliberately running low pressures in your tyres..

[1]They sometimes look like two holes, one the mirror image of the other.

There may also be other reasons for unexplained punctures, e.g. someone
sticking a knife in your tyre, thorns entering and leaveing (esp. old
tyres), inner tubes too small for the tyre etc.

Martin.

It happens if the tyre isn't inflated enough. If you go over a kerb the tyre
could swash enough to allow the tube to be pinched between the kerb and the
rim, you end up with two punctures on the inner part of the tube, aka snake
bites.

Jim J

"Marco" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Hi

What is a "pinch-puncture" and how do you avoid them?

I've had several punctures lately, for no apparent reason (nothing
poking thru the tyre) so I think I may be getting pinch-punctures but
don't know what they are or what to do about them!

Thanks in advance

Marco said:

Hi

What is a "pinch-puncture" and how do you avoid them?

I've had several punctures lately, for no apparent reason (nothing
poking thru the tyre) so I think I may be getting pinch-punctures but
don't know what they are or what to do about them!

Thanks in advance

Where the tube gets pinched between the ground and the rim, usually
after hitting a pothole. I had one a few months back when I hit a
pothole particularly hard and ended up with two parallel 1 cm long
gashes in the inner tube. I make sure I regularly check tyre pressure
now.

Martin Dann said:

A pinch puncture (aka snake bite[1]) is when the wheel rim bottoms out
onto the tyre pinching the inner tube.
If you ride totally on road you should never get these, and if you do
your tyres are not pumped up enough.

Off road, again, you need to pump up your tyres more. These can occur
a lot off road if you are deliberately running low pressures in your
tyres..
[1]They sometimes look like two holes, one the mirror image of the
other.

There may also be other reasons for unexplained punctures, e.g.
someone sticking a knife in your tyre, thorns entering and leaveing
(esp. old tyres), inner tubes too small for the tyre etc.

And rim tape being no good. This can result in a sort of pinch puncture as
well.

~PB

In message <[email hidden]>
"Pete Biggs"

Quoted message said:

Martin Dann said:

A pinch puncture (aka snake bite[1]) is when the wheel rim bottoms out
onto the tyre pinching the inner tube.

So what is a puncture called when you pinch the inner tube with the
beading as you put the cover back on after mending a puncture?

Quoted message said:

And rim tape being no good. This can result in a sort of pinch puncture as
well.

I thought rim tape was that strip of rust-marked cotton (or rubber)
masking spoke nipples from the inner tube, and rarely causes
punctures. What generic name should anti-puncture tape , fitted
between outer cover and tube and inflicting punctures , have?

--
Charles
Brompton P6R-Plus; CarryFreedom -YL, in Motspur Park
LCC; CTC.

Quoted message said:

I thought rim tape was that strip of rust-marked cotton (or rubber)
masking spoke nipples from the inner tube, and rarely causes
punctures.

After about 4 flats (honestly lost count) on my first MTB group ride,
the penny finally dropped that they were all on the spoke side of the
tube, due to the rubbish rubber rim strip having been moved sideways
(by me, the careless user....) exposing the edge of some of the spoke
holes in the double wall rim 🙁
I am now a Velox convert 🙂

Quoted message said:

What generic name should anti-puncture tape , fitted
between outer cover and tube and inflicting punctures , have?

tyre liner?

squeaker said the following on 19/10/2007 08:51:

Quoted message said:

I am now a Velox convert 🙂

Good man! The only rim tape worth using :-)

--
Paul Boyd
http://www.paul-boyd.co.uk/

Martin Dann said:

There may also be other reasons for unexplained punctures, e.g. someone
sticking a knife in your tyre, thorns entering and leaveing (esp. old
tyres), inner tubes too small for the tyre etc.

Martin.

If the punctures are in the same place, it could be that whatever
caused the original one is still in the tyre. It happened to me a
couple of years ago when I picked up a bit of wire that broke off on
the outside leaving no trace, but with just enough left on the inside
to pierce the tube when the tyre was pumped up and went over a bump.
The same can happen with a bit of glass that's worked its way
completely into the tye.
I located it eventually by marking where the punctures were occurring,
then rubbing my finger along the inside of the tyre while flexing it.
You risk cutting your finger, of course, but I thought it was worth
it.

Quoted message said:

So what is a puncture called when you pinch the inner tube with the
beading as you put the cover back on after mending a puncture?

'Bloody annoying' or, more correctly 'Operator Error'.

David Lloyd

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

In message <[email hidden]>
"Pete Biggs"

Quoted message said:

Martin Dann said:

A pinch puncture (aka snake bite[1]) is when the wheel rim bottoms out
onto the tyre pinching the inner tube.

So what is a puncture called when you pinch the inner tube with the
beading as you put the cover back on after mending a puncture?

Carelessness ;^>

Quoted message said:

Quoted message said:

And rim tape being no good. This can result in a sort of pinch puncture as
well.

I thought rim tape was that strip of rust-marked cotton (or rubber)
masking spoke nipples from the inner tube, and rarely causes
punctures.

The yellow plastic stuff has a tendency to split, exposing the tube to a
rough edge. Anything but the correct Velox tape on a single-eyelet box-
section rim can shift, letting the tube escape. The beige plastic stuff
tends to squirm up the rim, stopping the tyre bead from seating
properly, which can cause a blow-off. Can you still get the soft cotton
tape with a 'buckle' that sits on the valve hole?

Quoted message said:

What generic name should anti-puncture tape , fitted
between outer cover and tube and inflicting punctures , have?

The original was called Tuffy Tape, so maybe Duffy Tape?

Quoted message said:

I thought rim tape was that strip of rust-marked cotton (or rubber)
masking spoke nipples from the inner tube, and rarely causes
punctures.

It also needs to stop the tube being forced down the holes in rims with
recessed spokes.

A puncture is caused when the rim tape doesn't work.

~PB

Rob Morley said:

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

In message <[email hidden]>
"Pete Biggs"

Quoted message said:

Martin Dann wrote:
> A pinch puncture (aka snake bite[1]) is when the wheel rim bottoms out
> onto the tyre pinching the inner tube.

So what is a puncture called when you pinch the inner tube with the
beading as you put the cover back on after mending a puncture?

Carelessness ;^>

Quoted message said:

Quoted message said:

And rim tape being no good. This can result in a sort of pinch
puncture as well.

I thought rim tape was that strip of rust-marked cotton (or rubber)
masking spoke nipples from the inner tube, and rarely causes
punctures.

The yellow plastic stuff has a tendency to split, exposing the tube to a
rough edge. Anything but the correct Velox tape on a single-eyelet box-
section rim can shift, letting the tube escape. The beige plastic stuff
tends to squirm up the rim, stopping the tyre bead from seating
properly, which can cause a blow-off. Can you still get the soft cotton
tape with a 'buckle' that sits on the valve hole?

no idea about still getting, but fairly sure some of the old bikes have
that in the shed at my folks place.

Quoted message said:

Quoted message said:

What generic name should anti-puncture tape , fitted
between outer cover and tube and inflicting punctures , have?

The original was called Tuffy Tape, so maybe Duffy Tape?

roger
--
www.rogermerriman.com