Tire Bead Failure Epidemic

My last four (over a year) flat tires have been bead failures.

Before that, 100% were through-the-tread holes, either worn or
punctureed.

Is there a new tire construction method that results in really
crummy beads?

Another odd fact : all bought from Nashbar (though not the same
brand).

None not bought from Nashbar, before that, have had bead failures.

Perhaps a Nashbar supplier?

--
Ron Hardin


On the internet, nobody knows you're a jerk.

Ron Hardin wrote:
My last four (over a year) flat tires have been bead failures.

Before that, 100% were through-the-tread holes, either worn or
punctureed.

Is there a new tire construction method that results in really
crummy beads?


What do you mean "bead failure"? Do the beads of the tire *break*? Or
does the tire blow out along the rim?

I've never seen a bead break in 25 years of working on bikes. Usually
it's something close- rim cuts, brake shoe cuts, etc. Also, Jobst has
shown that a tire with a cut bead will hold fine when mounted properly
on a hook-bead rim.

Jeff

JeffWills wrote:

Ron Hardin wrote:
My last four (over a year) flat tires have been bead failures.

Before that, 100% were through-the-tread holes, either worn or
punctureed.

Is there a new tire construction method that results in really
crummy beads?


What do you mean "bead failure"? Do the beads of the tire *break*? Or
does the tire blow out along the rim?

I've never seen a bead break in 25 years of working on bikes. Usually
it's something close- rim cuts, brake shoe cuts, etc. Also, Jobst has
shown that a tire with a cut bead will hold fine when mounted properly
on a hook-bead rim.

Jeff

The casing wears through at the bead; this roughens the inside of the
tire, resulting in a leak in the tube when it in turn wears through
from abrading against the casing.

So the immediate cause is the threads in the casing breaking loose from
the casing and causing wear on the tube. If it didn't do that first,
it would be a separation of the tire casing at the bead and the tube
coming through, pretty soon.

I've put, gee, probably 300k miles on bikes now, and only recently
have I seen this failure. For years and years and years, it was
something in the tread, either wearing through (and my not watching
carefully enough) or a puncture.

Now it's at the bead.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

Ron Hardin wrote:
My last four (over a year) flat tires have been bead failures.

Before that, 100% were through-the-tread holes, either worn or
punctureed.

Is there a new tire construction method that results in really
crummy beads?

Another odd fact : all bought from Nashbar (though not the same
brand).

None not bought from Nashbar, before that, have had bead failures.

Perhaps a Nashbar supplier?


Same tire brand / model? Same wheel? Same batch?

On Wed, 28 Jun 2006 18:34:51 GMT, Ron Hardin
wrote:

JeffWills wrote:

Ron Hardin wrote:
My last four (over a year) flat tires have been bead failures.

Before that, 100% were through-the-tread holes, either worn or
punctureed.

Is there a new tire construction method that results in really
crummy beads?


What do you mean "bead failure"? Do the beads of the tire *break*? Or
does the tire blow out along the rim?

I've never seen a bead break in 25 years of working on bikes. Usually
it's something close- rim cuts, brake shoe cuts, etc. Also, Jobst has
shown that a tire with a cut bead will hold fine when mounted properly
on a hook-bead rim.

Jeff

The casing wears through at the bead; this roughens the inside of the
tire, resulting in a leak in the tube when it in turn wears through
from abrading against the casing.

So the immediate cause is the threads in the casing breaking loose from
the casing and causing wear on the tube. If it didn't do that first,
it would be a separation of the tire casing at the bead and the tube
coming through, pretty soon.

I've put, gee, probably 300k miles on bikes now, and only recently
have I seen this failure. For years and years and years, it was
something in the tread, either wearing through (and my not watching
carefully enough) or a puncture.

Now it's at the bead.

Are these all on the same wheel?

JT


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Ron Hardin wrote:

My last four (over a year) flat tires have been bead failures.

Before that, 100% were through-the-tread holes, either worn or
punctureed.

Is there a new tire construction method that results in really
crummy beads?

Another odd fact : all bought from Nashbar (though not the same
brand).

None not bought from Nashbar, before that, have had bead failures.

Perhaps a Nashbar supplier?

To answer some of the questions, a pic
http://home.att.net/~rhhardin6/tire001.jpg (55 kb)

a picture of the INSIDE of the tire. As it happens, this time a
Kenda 1.95x26

There's lots of tread left, so it's way premature.

The flat comes from the broken-loose threads abrading the tube, but it would
soon be tube-poking-through-sidewall if it continued, I imagine.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

Ron Hardin wrote:


The casing wears through at the bead; this roughens the inside of the
tire, resulting in a leak in the tube when it in turn wears through
from abrading against the casing.

So the immediate cause is the threads in the casing breaking loose from
the casing and causing wear on the tube. If it didn't do that first,
it would be a separation of the tire casing at the bead and the tube
coming through, pretty soon.

I've put, gee, probably 300k miles on bikes now, and only recently
have I seen this failure. For years and years and years, it was
something in the tread, either wearing through (and my not watching
carefully enough) or a puncture.

Now it's at the bead.

Make sure the brake pads aren't peeking over the top of the rim and
abrading the tire. I had many years of experience as well when I made
this mistake - such a silly mistake that I didn't bother to check until
several tires were shot.

Mark

Ron Hardin wrote:
My last four (over a year) flat tires have been bead failures.
Before that, 100% were through-the-tread holes, either worn or
punctureed.
Is there a new tire construction method that results in really
crummy beads?
Another odd fact : all bought from Nashbar (though not the same
brand).
None not bought from Nashbar, before that, have had bead failures.
Perhaps a Nashbar supplier?

Maybe it's the way they fold the tires when they ship
them to you? I'm assuming these are wire bead tires.
There is a way to coil up wire bead tires without
damaging them (it's in the FAQ) although I sometimes
find it hard to use on MTB tires.

Mark wrote:
Ron Hardin wrote:
The casing wears through at the bead; this roughens the inside of the
tire, resulting in a leak in the tube when it in turn wears through
from abrading against the casing.

Make sure the brake pads aren't peeking over the top of the rim and
abrading the tire. I had many years of experience as well when I made
this mistake - such a silly mistake that I didn't bother to check until
several tires were shot.

Ditto. I think it only took me one tyre, but I learned the hard way too.

--
Dave
dvt at psu dot edu

Everyone confesses that exertion which brings out all the powers of body
and mind is the best thing for us; but most people do all they can to
get rid of it, and as a general rule nobody does much more than
circumstances drive them to do. -Harriet Beecher Stowe, abolitionist and
novelist (1811-1896)

Wed, 28 Jun 2006 19:05:52 GMT, Ron Hardin:


To answer some of the questions, a pic
http://home.att.net/~rhhardin6/tire001.jpg (55 kb)

a picture of the INSIDE of the tire. As it happens, this time a
Kenda 1.95x26

There's lots of tread left, so it's way premature.

Tire too wide for the rim and pressure too low? A tire of this width (I
presume it is in the 50-60mm wide range) should be used with a rim of at
least 24mm inner width.

Andreas