blown tire

[carlfogel@comcast.net]

A Nashbar 27" tire from the previous century passed away, probably
none too quietly, while sitting in the garage.

It had been pumped up a week earlier to its usual 90 psi and ridden
gently several times, literally by a little old lady, but it decided
after its last ride that life was just too hard:

http://i12.tinypic.com/6wooh39.jpg

http://i10.tinypic.com/85cwkur.jpg

It didn't look as if the bead crept off the rim, more like dry rot.

Cheers,

Carl Fogel

[Werehatrack]

On Mon, 19 Nov 2007 14:52:06 -0700, carlfogel@comcast.net may have
said:

>A Nashbar 27" tire from the previous century passed away, probably
>none too quietly, while sitting in the garage.
>
>It had been pumped up a week earlier to its usual 90 psi and ridden
>gently several times, literally by a little old lady, but it decided
>after its last ride that life was just too hard:
>
> http://i12.tinypic.com/6wooh39.jpg
>
> http://i10.tinypic.com/85cwkur.jpg
>
>It didn't look as if the bead crept off the rim, more like dry rot.

One word: Gumwalls.

I see that kind of thing all the time. Bikes that come into thrift
stores with gumwall tires can almost always be relied upon to need a
new set, while blackwalls have a decent chance of being safe to ride
even if they're fairly old.

Note that the black rubber of the tread is still apparently sound.


--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

[A Muzi]

carlfogel@comcast.net wrote:
> A Nashbar 27" tire from the previous century passed away, probably
> none too quietly, while sitting in the garage.
>
> It had been pumped up a week earlier to its usual 90 psi and ridden
> gently several times, literally by a little old lady, but it decided
> after its last ride that life was just too hard:
>
> http://i12.tinypic.com/6wooh39.jpg
>
> http://i10.tinypic.com/85cwkur.jpg
>
> It didn't look as if the bead crept off the rim, more like dry rot.

Schwinn Continental ladies'? Suburbans came with painted mudguards IIRC.

The tire fabric has failed although 'dry rot' is an often used misnomer
for nylon fabric. Older cotton tires are coarser material generally and
usually show darkened areas where they have let water into the fabric
matrix before failure. The dry rot fungus is rare in bicycle tires.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

[Orin]

On Nov 19, 1:52 pm, carlfo...@comcast.net wrote:
> A Nashbar 27" tire from the previous century passed away, probably
> none too quietly, while sitting in the garage.
>
> It had been pumped up a week earlier to its usual 90 psi and ridden
> gently several times, literally by a little old lady, but it decided
> after its last ride that life was just too hard:
>
> http://i12.tinypic.com/6wooh39.jpg

Brake pad looks like it's not parallel to the rim and rubbing on the
tire, though it could be the camera angle.

> http://i10.tinypic.com/85cwkur.jpg

Look at the sidewall nearest the rim to the right of the 'hole'. No
rubber left on the cords.

I'd check the brake pads as well.

Orin.

[lemmiwinks.au@gmail.com]

On Nov 20, 9:08 am, Werehatrack <raul...@earthWEEDSlink.net> wrote:
> On Mon, 19 Nov 2007 14:52:06 -0700, carlfo...@comcast.net may have
> said:
>
> >A Nashbar 27" tire from the previous century passed away, probably
> >none too quietly, while sitting in the garage.
>
> >It had been pumped up a week earlier to its usual 90 psi and ridden
> >gently several times, literally by a little old lady, but it decided
> >after its last ride that life was just too hard:
>
> >http://i12.tinypic.com/6wooh39.jpg
>
> >http://i10.tinypic.com/85cwkur.jpg
>
> >It didn't look as if the bead crept off the rim, more like dry rot.
>
> One word: Gumwalls.
>
> I see that kind of thing all the time. Bikes that come into thrift
> stores with gumwall tires can almost always be relied upon to need a
> new set, while blackwalls have a decent chance of being safe to ride
> even if they're fairly old.
>
> Note that the black rubber of the tread is still apparently sound.

I've had two go recently, one gumwall, one blackwall. Both had been
in the weather for an unknown period of time but still had enough
tread that even though they were perished I decided to use them
anyway. Got a few hundred km out of each before they bulged, in both
instances the case of the tyre tore across the tread, almost down the
centre. I got my value out of them, I've got brand new tyres on
now :-)

[carlfogel@comcast.net]

On Mon, 19 Nov 2007 18:32:42 -0600, A Muzi <am@yellowjersey.org>
wrote:

>carlfogel@comcast.net wrote:
>> A Nashbar 27" tire from the previous century passed away, probably
>> none too quietly, while sitting in the garage.
>>
>> It had been pumped up a week earlier to its usual 90 psi and ridden
>> gently several times, literally by a little old lady, but it decided
>> after its last ride that life was just too hard:
>>
>> http://i12.tinypic.com/6wooh39.jpg
>>
>> http://i10.tinypic.com/85cwkur.jpg
>>
>> It didn't look as if the bead crept off the rim, more like dry rot.
>
>Schwinn Continental ladies'? Suburbans came with painted mudguards IIRC.
>
>The tire fabric has failed although 'dry rot' is an often used misnomer
>for nylon fabric. Older cotton tires are coarser material generally and
>usually show darkened areas where they have let water into the fabric
>matrix before failure. The dry rot fungus is rare in bicycle tires.

Dear Andrew.

A 10-speed with quick-releases and shiny fenders. The down-tube says
"Super Sport"--my guess is around 1972 or so.

The tire was a replacement from Nashbar.

Cheers,

Carl Fogel

[vey]

A Muzi wrote:
>The dry rot fungus is rare in bicycle tires.

Dry rot is common in Florida. We have lots of sunshine and heat and
humidity to assist in it's growth. Most bikes are kept inside, but the
ones that aren't or are kept near a window or in a hot storage shed will
get it even if they are ridden regularly.

[jobst.brandt@stanfordalumni.org]

Anadrew Muzi writes:

>> A Nashbar 27" tire from the previous century passed away, probably
>> none too quietly, while sitting in the garage.

>> It had been pumped up a week earlier to its usual 90 psi and ridden
>> gently several times, literally by a little old lady, but it decided
>> after its last ride that life was just too hard:

http://i12.tinypic.com/6wooh39.jpg

http://i10.tinypic.com/85cwkur.jpg

>> It didn't look as if the bead crept off the rim, more like dry rot.

> Schwinn Continental ladies'? Suburbans came with painted mudguards
> IIRC.

> The tire fabric has failed although 'dry rot' is an often used
> misnomer for nylon fabric. Older cotton tires are coarser material
> generally and usually show darkened areas where they have let water
> into the fabric matrix before failure. The dry rot fungus is rare in
> bicycle tires.

Besides, "dry rot" does not occur dry. It is only discovered when
dry. It's got to be soggy wet to have bacterial activity. Ancient
organic materials are found in the Sahara with no dry rot. Don't be
"mum" about that either. Tutankhamen knows!

Jobst Brandt

[A Muzi]

>> carlfogel@comcast.net wrote:
>>> A Nashbar 27" tire from the previous century passed away, probably
>>> none too quietly, while sitting in the garage.
>>> It had been pumped up a week earlier to its usual 90 psi and ridden
>>> gently several times, literally by a little old lady, but it decided
>>> after its last ride that life was just too hard:
>>> http://i12.tinypic.com/6wooh39.jpg
>>> http://i10.tinypic.com/85cwkur.jpg
>>> It didn't look as if the bead crept off the rim, more like dry rot.

> A Muzi <am@yellowjersey.org> wrote:
>> Schwinn Continental ladies'? Suburbans came with painted mudguards IIRC.
>> The tire fabric has failed although 'dry rot' is an often used misnomer
>> for nylon fabric. Older cotton tires are coarser material generally and
>> usually show darkened areas where they have let water into the fabric
>> matrix before failure. The dry rot fungus is rare in bicycle tires.

carlfogel@comcast.net wrote:
> A 10-speed with quick-releases and shiny fenders. The down-tube says
> "Super Sport"--my guess is around 1972 or so.
> The tire was a replacement from Nashbar.

Super Sport's a classy bike!
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

[Mike Jacoubowsky]

> A 10-speed with quick-releases and shiny fenders. The down-tube says
> "Super Sport"--my guess is around 1972 or so.

I was going to mention that it was a SuperSport, assuming the rims were
stock. The SuperSport was the least-expensive Schwinn model to have aluminum
rims at the time. Nice frame; instead of being butt-welded gas pipe tubing
(Varsity, Continental, Suburban) it was brazed ChromeMoly.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com


<carlfogel@comcast.net> wrote in message
news:dfe4k3d0u67lnu0p7j0tkue9p8pa8hnt29@4ax.com...
> On Mon, 19 Nov 2007 18:32:42 -0600, A Muzi <am@yellowjersey.org>
> wrote:
>
>>carlfogel@comcast.net wrote:
>>> A Nashbar 27" tire from the previous century passed away, probably
>>> none too quietly, while sitting in the garage.
>>>
>>> It had been pumped up a week earlier to its usual 90 psi and ridden
>>> gently several times, literally by a little old lady, but it decided
>>> after its last ride that life was just too hard:
>>>
>>> http://i12.tinypic.com/6wooh39.jpg
>>>
>>> http://i10.tinypic.com/85cwkur.jpg
>>>
>>> It didn't look as if the bead crept off the rim, more like dry rot.
>>
>>Schwinn Continental ladies'? Suburbans came with painted mudguards IIRC.
>>
>>The tire fabric has failed although 'dry rot' is an often used misnomer
>>for nylon fabric. Older cotton tires are coarser material generally and
>>usually show darkened areas where they have let water into the fabric
>>matrix before failure. The dry rot fungus is rare in bicycle tires.
>
> Dear Andrew.
>
> A 10-speed with quick-releases and shiny fenders. The down-tube says
> "Super Sport"--my guess is around 1972 or so.
>
> The tire was a replacement from Nashbar.
>
> Cheers,
>
> Carl Fogel

[carlfogel@comcast.net]

On Tue, 20 Nov 2007 09:32:32 -0800 (PST), Orin <orin.eman@gmail.com>
wrote:

>On Nov 19, 1:52 pm, carlfo...@comcast.net wrote:
>> A Nashbar 27" tire from the previous century passed away, probably
>> none too quietly, while sitting in the garage.
>>
>> It had been pumped up a week earlier to its usual 90 psi and ridden
>> gently several times, literally by a little old lady, but it decided
>> after its last ride that life was just too hard:
>>
>> http://i12.tinypic.com/6wooh39.jpg
>
>Brake pad looks like it's not parallel to the rim and rubbing on the
>tire, though it could be the camera angle.
>
>> http://i10.tinypic.com/85cwkur.jpg
>
>Look at the sidewall nearest the rim to the right of the 'hole'. No
>rubber left on the cords.
>
>I'd check the brake pads as well.
>
>Orin

Dear Orin,

Oh, don't be silly. I know beyond a shadow of a doubt that it must be
the camera angle.

1) I didn't notice anything wrong with the brakes when I fixed the
tire.

2) The brake pads have never been adjusted in thirty years or so, as
far as I can tell, much less replaced, so the brake pads couldn't be
misaligned--the tires would have burst long ago.

3) A quick look at the tire, which I kept, shows no circular scar
around the rest of the sidewall, which you'd expect if the pad were
attacking the sidewall.

4) Of course the damaged sidewall is missing material--it exploded.

So experience, logic, and investigation all show that you must be
mistaken and merely raising a straw man, a terrible habit on RBT. I
_know_ beyond a shadow of a doubt that the pad was not touching.

A glance at the brake pad proves that I'm--

Er, never mind what it proves.

If you don't tell anyone, no one will know how far I moved the right
front brake pad down a few minutes ago, before I took this picture:

http://i18.tinypic.com/6jojdvm.jpg

Well, they won't know unless they notice that mark above the nut on
the caliper arm, which shows how the pad was set too high for decades
and how far down I just moved it.

D'oh!

Despite scarcely any braking, the pad finally wore down enough against
the rim so that the unworn part began acting as a lathe on a faint
bulge on the sidewall, without leaving a circular scar on the rest of
the sidewall.

Here's undamaged side of the tire:

http://i12.tinypic.com/6ynsxds.jpg

The thin, regularly spaced white diagonals on the sidewall aren't
brake pad damage.

Here's the damaged side:

http://i9.tinypic.com/8amp2tz.jpg

The less regular, thicker white marks from about 10 to 2 o'clock show
where the brake pad was shaving the tire wherever the sidewall bulged
a tiny bit.

Thanks for the lesson in just how dumb I can be and why we shouldn't
trust so many posts that insist that such-and-so couldn't possibly
have happened.

By coincidence, I read "The Car Guys" last night:

Dear Tom and Ray: I have a 2002 Daewoo wagon. I have owned it since it
was new and have adequately maintained it, and it has just under
50,000 miles on it. Recently my husband checked the oil and added a
half-quart. Before long, I could see white smoke coming from the back
of the car. By the time I parked, the car was smoking profusely. I
opened the hood to find the oil cap missing and oil coating the inside
of the engine compartment and dripping on the driveway.

I know beyond a shadow of a doubt that my husband put the cap back on
properly. He tells me that the oil cap shot off. What happened? When I
brought it in to the service station (the same guys who have fixed and
serviced it for years), they told me that oil caps are not under any
pressure and will not "shoot off."

What do you think? - Leslie

Tom: Well, Leslie, we know beyond a shadow of a doubt that your
husband did not put the cap back on properly.

http://www.denverpost.com/search/ci_7492031

Now I feel guilty for snickering at Leslie and her husband.

I checked the other three pads. They're okay, but Andrew Muzi may not
hire me as a summer intern at Yellow Jersey.

Cheers,

Carl Fogel

[A Muzi]

carlfogel@comcast.net wrote:
> On Tue, 20 Nov 2007 09:32:32 -0800 (PST), Orin <orin.eman@gmail.com>
> wrote:
>
>> On Nov 19, 1:52 pm, carlfo...@comcast.net wrote:
>>> A Nashbar 27" tire from the previous century passed away, probably
>>> none too quietly, while sitting in the garage.
>>>
>>> It had been pumped up a week earlier to its usual 90 psi and ridden
>>> gently several times, literally by a little old lady, but it decided
>>> after its last ride that life was just too hard:
>>>
>>> http://i12.tinypic.com/6wooh39.jpg
>> Brake pad looks like it's not parallel to the rim and rubbing on the
>> tire, though it could be the camera angle.
>>
>>> http://i10.tinypic.com/85cwkur.jpg
>> Look at the sidewall nearest the rim to the right of the 'hole'. No
>> rubber left on the cords.
>>
>> I'd check the brake pads as well.
>>
>> Orin
>
> Dear Orin,
>
> Oh, don't be silly. I know beyond a shadow of a doubt that it must be
> the camera angle.
>
> 1) I didn't notice anything wrong with the brakes when I fixed the
> tire.
>
> 2) The brake pads have never been adjusted in thirty years or so, as
> far as I can tell, much less replaced, so the brake pads couldn't be
> misaligned--the tires would have burst long ago.
>
> 3) A quick look at the tire, which I kept, shows no circular scar
> around the rest of the sidewall, which you'd expect if the pad were
> attacking the sidewall.
>
> 4) Of course the damaged sidewall is missing material--it exploded.
>
> So experience, logic, and investigation all show that you must be
> mistaken and merely raising a straw man, a terrible habit on RBT. I
> _know_ beyond a shadow of a doubt that the pad was not touching.
>
> A glance at the brake pad proves that I'm--
>
> Er, never mind what it proves.
>
> If you don't tell anyone, no one will know how far I moved the right
> front brake pad down a few minutes ago, before I took this picture:
>
> http://i18.tinypic.com/6jojdvm.jpg
>
> Well, they won't know unless they notice that mark above the nut on
> the caliper arm, which shows how the pad was set too high for decades
> and how far down I just moved it.
>
> D'oh!
>
> Despite scarcely any braking, the pad finally wore down enough against
> the rim so that the unworn part began acting as a lathe on a faint
> bulge on the sidewall, without leaving a circular scar on the rest of
> the sidewall.
>
> Here's undamaged side of the tire:
>
> http://i12.tinypic.com/6ynsxds.jpg
>
> The thin, regularly spaced white diagonals on the sidewall aren't
> brake pad damage.
>
> Here's the damaged side:
>
> http://i9.tinypic.com/8amp2tz.jpg
>
> The less regular, thicker white marks from about 10 to 2 o'clock show
> where the brake pad was shaving the tire wherever the sidewall bulged
> a tiny bit.
>
> Thanks for the lesson in just how dumb I can be and why we shouldn't
> trust so many posts that insist that such-and-so couldn't possibly
> have happened.
>
> By coincidence, I read "The Car Guys" last night:
>
> Dear Tom and Ray: I have a 2002 Daewoo wagon. I have owned it since it
> was new and have adequately maintained it, and it has just under
> 50,000 miles on it. Recently my husband checked the oil and added a
> half-quart. Before long, I could see white smoke coming from the back
> of the car. By the time I parked, the car was smoking profusely. I
> opened the hood to find the oil cap missing and oil coating the inside
> of the engine compartment and dripping on the driveway.
>
> I know beyond a shadow of a doubt that my husband put the cap back on
> properly. He tells me that the oil cap shot off. What happened? When I
> brought it in to the service station (the same guys who have fixed and
> serviced it for years), they told me that oil caps are not under any
> pressure and will not "shoot off."
>
> What do you think? - Leslie
>
> Tom: Well, Leslie, we know beyond a shadow of a doubt that your
> husband did not put the cap back on properly.
>
> http://www.denverpost.com/search/ci_7492031
>
> Now I feel guilty for snickering at Leslie and her husband.
>
> I checked the other three pads. They're okay, but Andrew Muzi may not
> hire me as a summer intern at Yellow Jersey.

Not a damning tale. You learned about centerpull brake pad creep without
cosing my company a new tire?
Woo hoo it's like being shot at and missed!
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

[Mike Jacoubowsky]

> It had been pumped up a week earlier to its usual 90 psi and ridden
> gently several times, literally by a little old lady, but it decided
> after its last ride that life was just too hard:
(From your original post)

> 1) I didn't notice anything wrong with the brakes when I fixed the
> tire.
(Your most-recent post)

Carl: The tire obviously was bad, but I'm surprised that it ever held onto
the rim in the first place. Those rims had no hook for the tire's bead, and
generally weren't safe past about 70psi or so.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com


<carlfogel@comcast.net> wrote in message
news:hfa6k35cddiv1dks1il9v1melao8tbvs1t@4ax.com...
> On Tue, 20 Nov 2007 09:32:32 -0800 (PST), Orin <orin.eman@gmail.com>
> wrote:
>
>>On Nov 19, 1:52 pm, carlfo...@comcast.net wrote:
>>> A Nashbar 27" tire from the previous century passed away, probably
>>> none too quietly, while sitting in the garage.
>>>
>>> It had been pumped up a week earlier to its usual 90 psi and ridden
>>> gently several times, literally by a little old lady, but it decided
>>> after its last ride that life was just too hard:
>>>
>>> http://i12.tinypic.com/6wooh39.jpg
>>
>>Brake pad looks like it's not parallel to the rim and rubbing on the
>>tire, though it could be the camera angle.
>>
>>> http://i10.tinypic.com/85cwkur.jpg
>>
>>Look at the sidewall nearest the rim to the right of the 'hole'. No
>>rubber left on the cords.
>>
>>I'd check the brake pads as well.
>>
>>Orin
>
> Dear Orin,
>
> Oh, don't be silly. I know beyond a shadow of a doubt that it must be
> the camera angle.
>
> 1) I didn't notice anything wrong with the brakes when I fixed the
> tire.
>
> 2) The brake pads have never been adjusted in thirty years or so, as
> far as I can tell, much less replaced, so the brake pads couldn't be
> misaligned--the tires would have burst long ago.
>
> 3) A quick look at the tire, which I kept, shows no circular scar
> around the rest of the sidewall, which you'd expect if the pad were
> attacking the sidewall.
>
> 4) Of course the damaged sidewall is missing material--it exploded.
>
> So experience, logic, and investigation all show that you must be
> mistaken and merely raising a straw man, a terrible habit on RBT. I
> _know_ beyond a shadow of a doubt that the pad was not touching.
>
> A glance at the brake pad proves that I'm--
>
> Er, never mind what it proves.
>
> If you don't tell anyone, no one will know how far I moved the right
> front brake pad down a few minutes ago, before I took this picture:
>
> http://i18.tinypic.com/6jojdvm.jpg
>
> Well, they won't know unless they notice that mark above the nut on
> the caliper arm, which shows how the pad was set too high for decades
> and how far down I just moved it.
>
> D'oh!
>
> Despite scarcely any braking, the pad finally wore down enough against
> the rim so that the unworn part began acting as a lathe on a faint
> bulge on the sidewall, without leaving a circular scar on the rest of
> the sidewall.
>
> Here's undamaged side of the tire:
>
> http://i12.tinypic.com/6ynsxds.jpg
>
> The thin, regularly spaced white diagonals on the sidewall aren't
> brake pad damage.
>
> Here's the damaged side:
>
> http://i9.tinypic.com/8amp2tz.jpg
>
> The less regular, thicker white marks from about 10 to 2 o'clock show
> where the brake pad was shaving the tire wherever the sidewall bulged
> a tiny bit.
>
> Thanks for the lesson in just how dumb I can be and why we shouldn't
> trust so many posts that insist that such-and-so couldn't possibly
> have happened.
>
> By coincidence, I read "The Car Guys" last night:
>
> Dear Tom and Ray: I have a 2002 Daewoo wagon. I have owned it since it
> was new and have adequately maintained it, and it has just under
> 50,000 miles on it. Recently my husband checked the oil and added a
> half-quart. Before long, I could see white smoke coming from the back
> of the car. By the time I parked, the car was smoking profusely. I
> opened the hood to find the oil cap missing and oil coating the inside
> of the engine compartment and dripping on the driveway.
>
> I know beyond a shadow of a doubt that my husband put the cap back on
> properly. He tells me that the oil cap shot off. What happened? When I
> brought it in to the service station (the same guys who have fixed and
> serviced it for years), they told me that oil caps are not under any
> pressure and will not "shoot off."
>
> What do you think? - Leslie
>
> Tom: Well, Leslie, we know beyond a shadow of a doubt that your
> husband did not put the cap back on properly.
>
> http://www.denverpost.com/search/ci_7492031
>
> Now I feel guilty for snickering at Leslie and her husband.
>
> I checked the other three pads. They're okay, but Andrew Muzi may not
> hire me as a summer intern at Yellow Jersey.
>
> Cheers,
>
> Carl Fogel

[Orin]

On Nov 20, 11:40 am, carlfo...@comcast.net wrote:
>
> If you don't tell anyone, no one will know how far I moved the right
> front brake pad down a few minutes ago, before I took this picture:
>
> http://i18.tinypic.com/6jojdvm.jpg

Ah, much better camera angle ;)

Orin.

[Werehatrack]

On Tue, 20 Nov 2007 14:18:51 -0600, A Muzi <am@yellowjersey.org> may
have said:

>carlfogel@comcast.net wrote:
>> I checked the other three pads. They're okay, but Andrew Muzi may not
>> hire me as a summer intern at Yellow Jersey.
>
>Not a damning tale. You learned about centerpull brake pad creep without
>cosing my company a new tire?
>Woo hoo it's like being shot at and missed!

At that range, he'd have needed *really good* aim.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

[Werehatrack]

On 20 Nov 2007 23:49:35 GMT, jobst.brandt@stanfordalumni.org may have
said:

>Besides, "dry rot" does not occur dry. It is only discovered when
>dry. It's got to be soggy wet to have bacterial activity. Ancient
>organic materials are found in the Sahara with no dry rot. Don't be
>"mum" about that either. Tutankhamen knows!

Eh, dry rot in wood can occur without it having to be sodden. I've
had to replace enough of it in places where it couldn't have been
actually wet. Of course, we're talking about wood in a climate where
the humidity seldom falls below 35%.

Gumwall "dry rot" is a misnomer IMO. I'm pretty sure it's actually a
UV- and ozone-driven degradation of the rubber that's involved. The
gum rubber gets hard, dark, slightly more transparent than when fresh,
and brittle. When such a tire is pressurized with the gum in that
state, the rubber shatters and the cords are no longer constrained to
remain in patterned layers; blowout follows.

In a different material, I have had the urethane shells of dead-blow
hammers literally fragment into tiny pieces while sitting in a drawer
of a tool box, and the butyrate handles of many of my screwdriver
handles have fallen apart while exududing an oily residue that smelled
of acetic acid. Others have developed a white, biologic-looking
coating (on clear plastic whose composition I havent' tried to
establish) but have remained sound for over a decade after the stuff
first began to appear. The latter phenomenon is transferable; if an
afflicted handle is placed among previously unafflicted ones of the
same material, the others soon develop the same problem; this leads me
to believe that a plastic-eating fungus (or some other microbe) is
involved, but it's too small to discern with either of my microscopes.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

[A Muzi]

> jobst.brandt@stanfordalumni.org may have said:
>> Besides, "dry rot" does not occur dry. It is only discovered when
>> dry. It's got to be soggy wet to have bacterial activity. Ancient
>> organic materials are found in the Sahara with no dry rot. Don't be
>> "mum" about that either. Tutankhamen knows!

Werehatrack wrote:
> Eh, dry rot in wood can occur without it having to be sodden. I've
> had to replace enough of it in places where it couldn't have been
> actually wet. Of course, we're talking about wood in a climate where
> the humidity seldom falls below 35%.
>
> Gumwall "dry rot" is a misnomer IMO. I'm pretty sure it's actually a
> UV- and ozone-driven degradation of the rubber that's involved. The
> gum rubber gets hard, dark, slightly more transparent than when fresh,
> and brittle. When such a tire is pressurized with the gum in that
> state, the rubber shatters and the cords are no longer constrained to
> remain in patterned layers; blowout follows.
>
> In a different material, I have had the urethane shells of dead-blow
> hammers literally fragment into tiny pieces while sitting in a drawer
> of a tool box, and the butyrate handles of many of my screwdriver
> handles have fallen apart while exududing an oily residue that smelled
> of acetic acid. Others have developed a white, biologic-looking
> coating (on clear plastic whose composition I havent' tried to
> establish) but have remained sound for over a decade after the stuff
> first began to appear. The latter phenomenon is transferable; if an
> afflicted handle is placed among previously unafflicted ones of the
> same material, the others soon develop the same problem; this leads me
> to believe that a plastic-eating fungus (or some other microbe) is
> involved, but it's too small to discern with either of my microscopes.

I agree that the dry rot fungus doesn't affect nylon tires.

We discussed degradation (UV, ozone, outgassing etc) of polymers and
epoxies here, to death, a month or two ago. Much agree these materials
are not stable over multiple decades, most are perfectly useful over a
5~10 year 'life'.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

[jobst.brandt@stanfordalumni.org]

Were's the hatrack writes:

>> Besides, "dry rot" does not occur dry. It is only discovered when
>> dry. It's got to be soggy wet to have bacterial activity. Ancient
>> organic materials are found in the Sahara with no dry rot. Don't
>> be "mum" about that either. Tutankhamen knows!

> Eh, dry rot in wood can occur without it having to be sodden. I've
> had to replace enough of it in places where it couldn't have been
> actually wet. Of course, we're talking about wood in a climate
> where the humidity seldom falls below 35%.

Dry rot is not dry! It is only dry when discovered and that occurs
most often at time of failure when the fibrous elements are dry and
most brittle.

> Gumwall "dry rot" is a misnomer IMO. I'm pretty sure it's actually a
> UV- and ozone-driven degradation of the rubber that's involved. The
> gum rubber gets hard, dark, slightly more transparent than when fresh,
> and brittle. When such a tire is pressurized with the gum in that
> state, the rubber shatters and the cords are no longer constrained to
> remain in patterned layers; blowout follows.

I'm not ready to quibble about the various causes of bicycle tire
failures. I am not sure the materials (cords and tread rubber) are as
good as those used for cars. My Continentals have fraying sidewalls
and cracking tread rubber with less than a year old. To make up for
that, they seem to wear slowly for the mileage.

Jobst Brandt

[r15757@aol.com]

On Nov 20, 10:13 pm, jobst.bra...@stanfordalumni.org wrote:

> I'm not ready to quibble about the various causes of bicycle tire
> failures. I am not sure the materials (cords and tread rubber) are as
> good as those used for cars. My Continentals have fraying sidewalls
> and cracking tread rubber with less than a year old. To make up for
> that, they seem to wear slowly for the mileage.

But the sidewall will fail with many miles still left on the tread!
Continentals have become notorious for that. Maybe they started making
the flimsiest sidewalls in tire history to help market those more
expensive tires with bizarre exoskeletans holding the sidewalls in.
They can go straight to hell with that crap.

I'm really liking the Vittorias lately.

Robert

[carlfogel@comcast.net]

On Wed, 21 Nov 2007 16:37:26 GMT, "Mike Jacoubowsky"
<mikej1@ix.netcom.com> wrote:

>> A 10-speed with quick-releases and shiny fenders. The down-tube says
>> "Super Sport"--my guess is around 1972 or so.
>
>I was going to mention that it was a SuperSport, assuming the rims were
>stock. The SuperSport was the least-expensive Schwinn model to have aluminum
>rims at the time. Nice frame; instead of being butt-welded gas pipe tubing
>(Varsity, Continental, Suburban) it was brazed ChromeMoly.
>
>--Mike-- Chain Reaction Bicycles
>www.ChainReactionBicycles.com

Dear Mike,

Yes, it's stock as far as I can tell, except for a silly seat, a
wicker basket, some replaced cables, and the tires.

The red brake pads are original, and show hardly any wear. I doubt
that it's been ridden two hundred miles a year.

Cheers,

Carl Fogel

[carlfogel@comcast.net]

On Wed, 21 Nov 2007 17:14:07 GMT, "Mike Jacoubowsky"
<mikej1@ix.netcom.com> wrote:

>> It had been pumped up a week earlier to its usual 90 psi and ridden
>> gently several times, literally by a little old lady, but it decided
>> after its last ride that life was just too hard:
>(From your original post)
>
>> 1) I didn't notice anything wrong with the brakes when I fixed the
>> tire.
>(Your most-recent post)
>
>Carl: The tire obviously was bad, but I'm surprised that it ever held onto
>the rim in the first place. Those rims had no hook for the tire's bead, and
>generally weren't safe past about 70psi or so.
>
>--Mike-- Chain Reaction Bicycles
>www.ChainReactionBicycles.com

Dear Mike,

The rider is about a hundred pounds and just rides slowly and gently
around my neighborhood, never shifting gears, so the tires have a
better chance of staying on the rims than usual.

I don't know what the original tires from Schwinn were rated for, but
the replacement tires from Nashbar were pre-2000 and have been pumped
to about 90 psi since then.

But what you say makes sense, so I'll probably go back and discreetly
lower the tire pressures, fore and aft.

Cheers,

Carl Fogel

[Mike Jacoubowsky]

> Yes, it's stock as far as I can tell, except for a silly seat, a
> wicker basket, some replaced cables, and the tires.

I would love to have a practical use for a bike with a wicker basket. Not
imitation, but the real thing. They look great on certain types of bikes.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com


<carlfogel@comcast.net> wrote in message
news:pp09k3183go4kcsbae29d6dli7lb2u1oqv@4ax.com...
> On Wed, 21 Nov 2007 16:37:26 GMT, "Mike Jacoubowsky"
> <mikej1@ix.netcom.com> wrote:
>
>>> A 10-speed with quick-releases and shiny fenders. The down-tube says
>>> "Super Sport"--my guess is around 1972 or so.
>>
>>I was going to mention that it was a SuperSport, assuming the rims were
>>stock. The SuperSport was the least-expensive Schwinn model to have
>>aluminum
>>rims at the time. Nice frame; instead of being butt-welded gas pipe tubing
>>(Varsity, Continental, Suburban) it was brazed ChromeMoly.
>>
>>--Mike-- Chain Reaction Bicycles
>>www.ChainReactionBicycles.com
>
> Dear Mike,
>
> Yes, it's stock as far as I can tell, except for a silly seat, a
> wicker basket, some replaced cables, and the tires.
>
> The red brake pads are original, and show hardly any wear. I doubt
> that it's been ridden two hundred miles a year.
>
> Cheers,
>
> Carl Fogel

[Michael]

carlfogel@comcast.net wrote:
>
> On Wed, 21 Nov 2007 16:37:26 GMT, "Mike Jacoubowsky"
> <mikej1@ix.netcom.com> wrote:
>
> >> A 10-speed with quick-releases and shiny fenders. The down-tube says
> >> "Super Sport"--my guess is around 1972 or so.
> >
> >I was going to mention that it was a SuperSport, assuming the rims were
> >stock. The SuperSport was the least-expensive Schwinn model to have aluminum
> >rims at the time. Nice frame; instead of being butt-welded gas pipe tubing
> >(Varsity, Continental, Suburban) it was brazed ChromeMoly.
> >
> >--Mike-- Chain Reaction Bicycles
> >www.ChainReactionBicycles.com
>
> Dear Mike,
>
> Yes, it's stock as far as I can tell, except for a silly seat, a
> wicker basket, some replaced cables, and the tires.
>
> The red brake pads are original, and show hardly any wear. I doubt
> that it's been ridden two hundred miles a year.
>
> Cheers,
>
> Carl Fogel


My World Voyager appears to have the same pads. They are original, not very
worn, with tons of life left. They are very hard and, as you might guess, they
are inefficient brakes! Compared to, e.g. KoolStop, these red blocks are
granite. Not sure how much the *age* of the rubber factors in. Just another
part of her way of being that I accept.


---
Michael

[Mike Jacoubowsky]

> I don't know what the original tires from Schwinn were rated for, but
> the replacement tires from Nashbar were pre-2000 and have been pumped
> to about 90 psi since then.
>
> But what you say makes sense, so I'll probably go back and discreetly
> lower the tire pressures, fore and aft.

That wouldn't be a bad idea. It's really dumb to have high PSI ratings on
27" tires, because there are *very* few 27" rims that have the required
"hook" for higher pressures. In virtually every application (old bikes),
60-70 PSI is about the max you can safely inflate to. And even then you have
to be careful about how they're mounted since, without a hook, the tire can
mis-position itself fairly easily. Sometimes they got around that by having
a very tight fit. Tire "irons" weren't just for motorcycle and car tires;
you sometimes needed something quite gnarly for older 27" steel rim. And
then you'd have an impossible time trying to get it to mount correctly
without a sunken spot that you couldn't get out.

Anyway, many bike shops can confirm the meaninglessness of tire pressure
limits on 27" tires, based upon the large number that come back with a
customer claiming the tire defective because it blew off the rim at the
pressure listed on the sidewall. It's something that I try to tell everyone
buying 27" tires.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com


<carlfogel@comcast.net> wrote in message
news:1219k3pm4pvgjot1d4h71r7m7jha490r7d@4ax.com...
> On Wed, 21 Nov 2007 17:14:07 GMT, "Mike Jacoubowsky"
> <mikej1@ix.netcom.com> wrote:
>
>>> It had been pumped up a week earlier to its usual 90 psi and ridden
>>> gently several times, literally by a little old lady, but it decided
>>> after its last ride that life was just too hard:
>>(From your original post)
>>
>>> 1) I didn't notice anything wrong with the brakes when I fixed the
>>> tire.
>>(Your most-recent post)
>>
>>Carl: The tire obviously was bad, but I'm surprised that it ever held onto
>>the rim in the first place. Those rims had no hook for the tire's bead,
>>and
>>generally weren't safe past about 70psi or so.
>>
>>--Mike-- Chain Reaction Bicycles
>>www.ChainReactionBicycles.com
>
> Dear Mike,
>
> The rider is about a hundred pounds and just rides slowly and gently
> around my neighborhood, never shifting gears, so the tires have a
> better chance of staying on the rims than usual.
>
> I don't know what the original tires from Schwinn were rated for, but
> the replacement tires from Nashbar were pre-2000 and have been pumped
> to about 90 psi since then.
>
> But what you say makes sense, so I'll probably go back and discreetly
> lower the tire pressures, fore and aft.
>
> Cheers,
>
> Carl Fogel

[Mark]

Mike Jacoubowsky wrote:
> It's really dumb to have high PSI ratings on
> 27" tires, because there are *very* few 27" rims that have the required
> "hook" for higher pressures. In virtually every application (old bikes),
> 60-70 PSI is about the max you can safely inflate to.

Huh? Just about all the aluminum 27" rims sold in the 80s had the
hooks. I know, now I'm stuck with a garage full of 'em and slim
pickings for tires. Even the straight-side (hookless) rims worked
nicely with the 85 psi "HP" tires of the 70's - though those had wire
beads; perhaps you're thinking of folding-bead tires. The hookless
Araya steel rim was a staple in entry-level 70's bikes, standard with
those 85 psi tires. IIRC, the Arayas fit tires far better than the
Schwinn steel rims of the era.

Any more, you're right, though, that there are few 27" rims with hooks,
b/c there are few 27" rims. At the rate the industry is going, I
sometimes worry that soon there will be very few /rims/ at all available
for purchase without a goofy hub already laced to them.

And even then you have
> to be careful about how they're mounted since, without a hook, the tire can
> mis-position itself fairly easily.

Agreed, esp. those Schwinn steel rims, which always seemed to have
sizing issues.

Sometimes they got around that by having
> a very tight fit. Tire "irons" weren't just for motorcycle and car tires;
> you sometimes needed something quite gnarly for older 27" steel rim. And
> then you'd have an impossible time trying to get it to mount correctly
> without a sunken spot that you couldn't get out.

With many brands of the era, yup. Though I recall the Japanese steel,
matched to Japanese rubber, fit quite nicely. I wrenched briefly in a
Raleigh shop at the time and hated trying to seat the stuff they sold,
but the Japanese stuff I grew up with didn't seem to have that problem.

> Anyway, many bike shops can confirm the meaninglessness of tire pressure
> limits on 27" tires, based upon the large number that come back with a
> customer claiming the tire defective because it blew off the rim at the
> pressure listed on the sidewall. It's something that I try to tell everyone
> buying 27" tires.

It's bizarre (IMHO) to see this attributed to the size. Cheap rims or
cheap rubber, which 27" now tends to be, but it ain't the size that's
the problem.

Mark J.

[Mike Jacoubowsky]

> Mike Jacoubowsky wrote:
>> It's really dumb to have high PSI ratings on 27" tires, because there are
>> *very* few 27" rims that have the required "hook" for higher pressures.
>> In virtually every application (old bikes), 60-70 PSI is about the max
>> you can safely inflate to.
>
> Huh? Just about all the aluminum 27" rims sold in the 80s had the hooks.
> I know, now I'm stuck with a garage full of 'em and slim pickings for
> tires. Even the straight-side (hookless) rims worked nicely with the 85
> psi "HP" tires of the 70's - though those had wire beads; perhaps you're
> thinking of folding-bead tires. The hookless Araya steel rim was a staple
> in entry-level 70's bikes, standard with those 85 psi tires. IIRC, the
> Arayas fit tires far better than the Schwinn steel rims of the era.

Oh sure, SuperChampion had some very nice rims that were available in 27"
(the Mod 58, for example). But for every 25 27" tires we sell, perhaps ONE
(and probably less) goes to a customer with a nice rim. The rest are all
going onto really junky stuff (old Firenzes and such).

> Any more, you're right, though, that there are few 27" rims with hooks,
> b/c there are few 27" rims. At the rate the industry is going, I
> sometimes worry that soon there will be very few /rims/ at all available
> for purchase without a goofy hub already laced to them.

We're pretty much already there. Not too many choices these days. Simply a
matter of the small size of that market.

> And even then you have
>> to be careful about how they're mounted since, without a hook, the tire
>> can mis-position itself fairly easily.
>
> Agreed, esp. those Schwinn steel rims, which always seemed to have sizing
> issues.
>
> Sometimes they got around that by having
>> a very tight fit. Tire "irons" weren't just for motorcycle and car tires;
>> you sometimes needed something quite gnarly for older 27" steel rim. And
>> then you'd have an impossible time trying to get it to mount correctly
>> without a sunken spot that you couldn't get out.
>
> With many brands of the era, yup. Though I recall the Japanese steel,
> matched to Japanese rubber, fit quite nicely. I wrenched briefly in a
> Raleigh shop at the time and hated trying to seat the stuff they sold, but
> the Japanese stuff I grew up with didn't seem to have that problem.

My first impression of a japanese bike was extremely favorable. The Cal
Clipper. I'd been trying to make entry-level ($130 at the time) Gitanes &
Merciers build up OK, having nightmares with chainrings (pretty much had to
"true" every single one, and look for bent teeth too), wheel issues and
frame alignment. Then we bring in this $90 Cal Clipper from a local
distributor. My gosh, the darned thing built in half the time and shifted &
braked twice as well! And the frame was perfect.

>> Anyway, many bike shops can confirm the meaninglessness of tire pressure
>> limits on 27" tires, based upon the large number that come back with a
>> customer claiming the tire defective because it blew off the rim at the
>> pressure listed on the sidewall. It's something that I try to tell
>> everyone buying 27" tires.
>
> It's bizarre (IMHO) to see this attributed to the size. Cheap rims or
> cheap rubber, which 27" now tends to be, but it ain't the size that's the
> problem.

Well, it's the size that makes it the problem. 27" lost out in the
marketplace, so what you come across, as a bike shop owner, are nearly
always problems. But I do understand your point.
>
> Mark J.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com