Two sidewall blowouts in three days...

[Travis]

I've just walked several km in 42 degree heat because my back tire
sidewall blew out... again. It happened two days ago as well.

On neither occasion did I hit anything, I was just riding along at a
moderate speed when suddenly there was a loud bang. I braked and the
tire was flat.

When it happened two days ago I just assumed it was a result of riding
around on dodgy threadbare tires, so after limping home I put on a
brand new tire (which was also a completely different brand) and set
off again.

Yesterday was fine, but today my (new) tire exploded again.

I swapped in a new tube, but only got 300m before I was rolling on
zero pressure, the tube had holed itself at the sidewall tear.

Since in all other respects I've not done anything differently in the
last three days to the previous year in which I've managed to avoid
explosive sidewall blowouts, I think I'll blame the heat. I've ridden
on hot days before, but I'm not sure if I've done such distances on
days as hot as this.

If its the heat, perhaps what happened was as my tires heated up their
pressure rose above their recommended pressure, and just popped from
overinflation.

If that's so, then I would avoid a repeat by not pumping up my tires
so high on really hot days.

I weigh 115kg, ride a standard skinny tired roadie, I've been
inflating my tires to 100psi for years with no problems.

But should I inflate them to 80psi on days like this?

Travis

 

[Duncan]

Can't help with your tyre woes, but in future, carry a small piece of
thin plastic in your repair kit (like laminating plastic sort of
thickness, I have heard that plastic dollar notes work, but I think
that's a bit thin).. you can place this betwixt tyre and tube and ride
quite successfully.

I used this technique just recently when a wayward rock damaged a
sidewall and the tube blew out through the hole..

 

[Bleve]

On Mar 7, 5:06 pm, "Travis" <[email protected]> wrote:
> I've just walked several km in 42 degree heat because my back tire
> sidewall blew out... again. It happened two days ago as well.

Heat shouldn't be a problem, your wheels will get a lot hotter on a
descent.


>
> On neither occasion did I hit anything, I was just riding along at a
> moderate speed when suddenly there was a loud bang. I braked and the
> tire was flat.

Was the tyre seated properly? Any obvious damage to your rim?


>
> When it happened two days ago I just assumed it was a result of riding
> around on dodgy threadbare tires, so after limping home I put on a
> brand new tire (which was also a completely different brand) and set
> off again.
>
> Yesterday was fine, but today my (new) tire exploded again.
>
> I swapped in a new tube, but only got 300m before I was rolling on
> zero pressure, the tube had holed itself at the sidewall tear.
>
> Since in all other respects I've not done anything differently in the
> last three days to the previous year in which I've managed to avoid
> explosive sidewall blowouts, I think I'll blame the heat. I've ridden
> on hot days before, but I'm not sure if I've done such distances on
> days as hot as this.

I've done 200km days in 40 degree heat, never had this problem.

> If its the heat, perhaps what happened was as my tires heated up their
> pressure rose above their recommended pressure, and just popped from
> overinflation.
>
> If that's so, then I would avoid a repeat by not pumping up my tires
> so high on really hot days.
>
> I weigh 115kg, ride a standard skinny tired roadie, I've been
> inflating my tires to 100psi for years with no problems.
>
> But should I inflate them to 80psi on days like this?

I wouldn't have thought so, but PV=nRT will let you figure out how
much the pressure will change (roughly)

 

[Donga]

On Mar 7, 4:06 pm, "Travis" <[email protected]> wrote:
> I've just walked several km in 42 degree heat because my back tire
> sidewall blew out... again. It happened two days ago as well.
>
> On neither occasion did I hit anything, I was just riding along at a
> moderate speed when suddenly there was a loud bang. I braked and the
> tire was flat.
>
> When it happened two days ago I just assumed it was a result of riding
> around on dodgy threadbare tires, so after limping home I put on a
> brand new tire (which was also a completely different brand) and set
> off again.
>
> Yesterday was fine, but today my (new) tire exploded again.
>
> I swapped in a new tube, but only got 300m before I was rolling on
> zero pressure, the tube had holed itself at the sidewall tear.
>
> Since in all other respects I've not done anything differently in the
> last three days to the previous year in which I've managed to avoid
> explosive sidewall blowouts, I think I'll blame the heat. I've ridden
> on hot days before, but I'm not sure if I've done such distances on
> days as hot as this.
>
> If its the heat, perhaps what happened was as my tires heated up their
> pressure rose above their recommended pressure, and just popped from
> overinflation.
>
> If that's so, then I would avoid a repeat by not pumping up my tires
> so high on really hot days.
>
> I weigh 115kg, ride a standard skinny tired roadie, I've been
> inflating my tires to 100psi for years with no problems.
>
> But should I inflate them to 80psi on days like this?
>
> Travis

Has the wheel been set off-centre and the tire rubbing on a stay, or
the brake block rubbing on the tire?

 

[monsterman]

I've just walked several km in 42 degree heat because my back tire
sidewall blew out... again. It happened two days ago as well.

On neither occasion did I hit anything, I was just riding along at a
moderate speed when suddenly there was a loud bang. I braked and the
tire was flat.

When it happened two days ago I just assumed it was a result of riding
around on dodgy threadbare tires, so after limping home I put on a
brand new tire (which was also a completely different brand) and set
off again.

Yesterday was fine, but today my (new) tire exploded again.

I swapped in a new tube, but only got 300m before I was rolling on
zero pressure, the tube had holed itself at the sidewall tear.

Since in all other respects I've not done anything differently in the
last three days to the previous year in which I've managed to avoid
explosive sidewall blowouts, I think I'll blame the heat. I've ridden
on hot days before, but I'm not sure if I've done such distances on
days as hot as this.

If its the heat, perhaps what happened was as my tires heated up their
pressure rose above their recommended pressure, and just popped from
overinflation.

If that's so, then I would avoid a repeat by not pumping up my tires
so high on really hot days.

I weigh 115kg, ride a standard skinny tired roadie, I've been
inflating my tires to 100psi for years with no problems.

But should I inflate them to 80psi on days like this?

Travis

I punctured my front on both Monday and Tuesday this week. And I checked the Tues tube carefully and it was not a pinch-flat. I cannot remember last time I punctured a front tire. Quite possibly as a kid 25 years ago. I think, like your recent events, my flats were just a case of "sh!t happens" Sometimes twice in a row

 

[DeF]

Travis wrote:
> I've just walked several km in 42 degree heat because my back tire
> sidewall blew out... again. It happened two days ago as well.
>
> On neither occasion did I hit anything, I was just riding along at a
> moderate speed when suddenly there was a loud bang. I braked and the
> tire was flat.
>
> When it happened two days ago I just assumed it was a result of riding
> around on dodgy threadbare tires, so after limping home I put on a
> brand new tire (which was also a completely different brand) and set
> off again.
>
> Yesterday was fine, but today my (new) tire exploded again.
>
> I swapped in a new tube, but only got 300m before I was rolling on
> zero pressure, the tube had holed itself at the sidewall tear.
>
> Since in all other respects I've not done anything differently in the
> last three days to the previous year in which I've managed to avoid
> explosive sidewall blowouts, I think I'll blame the heat. I've ridden
> on hot days before, but I'm not sure if I've done such distances on
> days as hot as this.
>
> If its the heat, perhaps what happened was as my tires heated up their
> pressure rose above their recommended pressure, and just popped from
> overinflation.
>
> If that's so, then I would avoid a repeat by not pumping up my tires
> so high on really hot days.
>
> I weigh 115kg, ride a standard skinny tired roadie, I've been
> inflating my tires to 100psi for years with no problems.
>
> But should I inflate them to 80psi on days like this?
>
> Travis
>

I've had two tire blowouts in the last year. I was able to explain
both of them.

1: Rear wheel of MTB commuter. Slick tires that had perished with
the help of over liberal application of chain lube. By pushing
my finger nail along the tire, I could scrape the rubber off.
Going down hill, about 35kph with 2.5yo in baby-seat. >BANG<
back is fishtailing around but I manage to bring it to a halt
without coming off.

2: Front wheel of my old tourer. Old tire with visible cracks due
to hardening. I also over inflated the tire - >BANG< 3km walk
home all barefoot with last km on gravel. Ouch.

I've also had a tube explode after putting on a new tire and not
checking proper tire seating. Small bit of tube was stuck under
the bead and rupture when pressure got to around 110psi.

You might just be having bad luck!

DeF.

--
e-mail: d.farrow@your finger.murdoch.edu.au
To reply, you'll have to remove your finger.

 

[Travis]

On Mar 7, 2:37 pm, "Bleve" <[email protected]> wrote:
> On Mar 7, 5:06 pm, "Travis" <[email protected]> wrote:
>
> > I've just walked several km in 42 degree heat because my back tire
> > sidewall blew out... again. It happened two days ago as well.
>
> Heat shouldn't be a problem, your wheels will get a lot hotter on a
> descent.

I take it therefore that you would advise me to always pump my tires
up to the same pressure, regardless of how hot it will be that day...

> > On neither occasion did I hit anything, I was just riding along at a
> > moderate speed when suddenly there was a loud bang. I braked and the
> > tire was flat.
>
> Was the tyre seated properly? Any obvious damage to your rim?

Yes. No.


> > If its the heat, perhaps what happened was as my tires heated up their
> > pressure rose above their recommended pressure, and just popped from
> > overinflation.
>
> > If that's so, then I would avoid a repeat by not pumping up my tires
> > so high on really hot days.
>
> > I weigh 115kg, ride a standard skinny tired roadie, I've been
> > inflating my tires to 100psi for years with no problems.
>
> > But should I inflate them to 80psi on days like this?
>
> I wouldn't have thought so, but PV=nRT will let you figure out how
> much the pressure will change (roughly)

Since V, n and R are all constant, P is proportional to T in Kelvins.

If tires are 100psi at 20C (293K) then at 50C (323K) pressure should
be around 10% higher (110PSI). The tire says it is rated to 130PSI,
to get to that pressure I'd need to be at a temperature 30% higher
than 293K, i.e. 381K or 108C. I know my tires probably got hot, but I
doubt they got that hot!

But to answer some of the other questions, no I can see no evidence of
any kind of damage or misalignment of the rim, wheels, brake pads or
anything else. I maintain the bike myself and everything looks to be
set up perfectly.

Maybe as one person suggested **** just happens! I will however see
if I can dig up a mylar sheet or something and pack it into my
emergency repair kit.

Travis

 

[rooman]

...not convinced on your ambient temp being primary cause..it is a factor ( sheesh 42C is not at all kind to tires or bodies) but...I would also check a few other items

• spoke protruding through rim into tube ( these when over tightened or adjusted can puncture tubes easily)
• rim tape too narrow and moved off centre allowing spoke hole edges to pinch tube on a random bump.
• 115kgs bodyweight and 100psi tire pressure is pushing it a bit.... pinch flat would be a probability...I know when I was over 110, I had the unwanted experience only too often of a puncture on my roadie tires when psi got below 105....I'm now 82kgs and I still keep the pressures up well over 110, usually 120 to 125 on 130psi rated tires.....(punctures.... ummm what are they...I hear people mention them....but I've forgotten what they are....)
• errant glass, fine sliver you may have missed and was still in tire.
• thorns
• puncture snakes
• you didnt really puncture, you just thought you did and took the wheel off to change it anyway...

good luck... its no fun no matter what the cause is...check pressures before every ride, especially after a layoff or rain...

 

[Travis]

On Mar 7, 3:56 pm, rooman <rooman.2n2...@no-
mx.forums.cyclingforums.com> wrote:
> ...not convinced on your ambient temp being primary cause..it is a
> factor ( sheesh 42C is not at all kind to tires or bodies) but...I
> would also check a few other items
>
> - spoke protruding through rim into tube ( these when over tightened
> or adjusted can puncture tubes easily)
> - rim tape too narrow and moved off centre allowing spoke hole edges
> to pinch tube on a random bump.
> - 115kgs bodyweight and 100psi tire pressure is pushing it a bit....
> pinch flat would be a probability...I know when I was over 110, I had
> the unwanted experience only too often of a puncture on my roadie
> tires when psi got below 105....I'm now 82kgs and I still keep the
> pressures up well over 110, usually 120 to 125 on 130psi rated
> tires.....(punctures.... ummm what are they...I hear people mention
> them....but I've forgotten what they are....)
> - errant glass, fine sliver you may have missed and was still in
> tire.
> - thorns
> - puncture snakes
> - you didnt really puncture, you just thought you did and took the
> wheel off to change it anyway...
>
> good luck... its no fun no matter what the cause is...check pressures
> before every ride, especially after a layoff or rain...

It was definitely a sidewall blowout... there is a bloody great big
hole in my sidewall! On my new tire it has propagated for some
distance. The tube is slit at that point.

I was riding on an apparently perfect surface, I backtracked today
looking for a rock or something but there was nothing. Just nice
smooth 1-year-old cycle path asphalt (both happened on the Roe Hwy
cycle path southeast of Murdoch Uni, though the incidents happened
about 4km apart).

I'm certain, based on careful inspection, that there is nothing wrong
with the rim, or any spokes, or the rim tape, or the brakes.

If its not the heat which did it, I don't know what it was!

Travis

 

[Boostland]

"Duncan" <[email protected]> wrote in message
news:[email protected]...
> Can't help with your tyre woes, but in future, carry a small piece of
> thin plastic in your repair kit (like laminating plastic sort of
> thickness, I have heard that plastic dollar notes work, but I think
> that's a bit thin).. you can place this betwixt tyre and tube and ride
> quite successfully.
>
> I used this technique just recently when a wayward rock damaged a
> sidewall and the tube blew out through the hole..
>

I carry bits of old tubulars and some bits of Zefal rim tape that I can use
to fix just about any sized cut.

My friend had a new Lithion tyre blow out the kevlar bead the other week and
he thought he was stuck, lucky I had my racing tubulars on and had my 2
spare tyres I carry.
I told him to put a tubular inside his clincher, it was a tight fit but it
worked perfectly and he was able to ride the 35 km home with no problems.

 

[Travis]

On Mar 7, 4:56 pm, rooman <rooman.2n2...@no-
mx.forums.cyclingforums.com> wrote:

> - 115kgs bodyweight and 100psi tire pressure is pushing it a bit....
> pinch flat would be a probability...I know when I was over 110, I had
> the unwanted experience only too often of a puncture on my roadie
> tires when psi got below 105....I'm now 82kgs and I still keep the
> pressures up well over 110, usually 120 to 125 on 130psi rated
> tires.....(punctures.... ummm what are they...I hear people mention
> them....but I've forgotten what they are....)

Ok, I'll bite... on 130psi rated tires how much pressure should I put
into them?

Travis

 

[rooman]

On Mar 7, 4:56 pm, rooman <rooman.2n2...@no-
mx.forums.cyclingforums.com> wrote:

> - 115kgs bodyweight and 100psi tire pressure is pushing it a bit....
> pinch flat would be a probability...I know when I was over 110, I had
> the unwanted experience only too often of a puncture on my roadie
> tires when psi got below 105....I'm now 82kgs and I still keep the
> pressures up well over 110, usually 120 to 125 on 130psi rated
> tires.....(punctures.... ummm what are they...I hear people mention
> them....but I've forgotten what they are....)

Ok, I'll bite... on 130psi rated tires how much pressure should I put
into them?

Travis

not over 130psi...

 

[Bugbear]

On Mar 7, 5:44 pm, "Travis" <[email protected]> wrote:
> It was definitely a sidewall blowout... there is a bloody great big
> hole in my sidewall! On my new tire it has propagated for some
> distance. The tube is slit at that point.
>
> I was riding on an apparently perfect surface, I backtracked today
> looking for a rock or something but there was nothing. Just nice
> smooth 1-year-old cycle path asphalt (both happened on the Roe Hwy
> cycle path southeast of Murdoch Uni, though the incidents happened
> about 4km apart).
>
> I'm certain, based on careful inspection, that there is nothing wrong
> with the rim, or any spokes, or the rim tape, or the brakes.
>
> If its not the heat which did it, I don't know what it was!
>
> Travis- Hide quoted text -
>
> - Show quoted text -
I know your pain, at least as far as riding in yesterday's heat. Roe
Hwy path isn't that clean though. There are several spots that I saw
yesterday that were littered with small rocks, and twigs.

At least the bogans haven't set to the path and spread broken glass
around (yet)...

 

[Bleve]

On Mar 8, 2:42 pm, "Travis" <[email protected]> wrote:
> On Mar 7, 4:56 pm, rooman <rooman.2n2...@no-
>
> mx.forums.cyclingforums.com> wrote:
> > - 115kgs bodyweight and 100psi tire pressure is pushing it a bit....
> > pinch flat would be a probability...I know when I was over 110, I had
> > the unwanted experience only too often of a puncture on my roadie
> > tires when psi got below 105....I'm now 82kgs and I still keep the
> > pressures up well over 110, usually 120 to 125 on 130psi rated
> > tires.....(punctures.... ummm what are they...I hear people mention
> > them....but I've forgotten what they are....)
>
> Ok, I'll bite... on 130psi rated tires how much pressure should I put
> into them?

There's some maths to determine 'ideal' pressures based on weight,
tyre size etc (it was published in one of the rags a few years ago
from memory), but I'd generally, at your weight, be running
100-120psi, on a 700x23 tyre, in the dry.

 

[rooman]

On Mar 8, 2:42 pm, "Travis" <[email protected]> wrote:
> On Mar 7, 4:56 pm, rooman <rooman.2n2...@no-
>
> mx.forums.cyclingforums.com> wrote:
> > - 115kgs bodyweight and 100psi tire pressure is pushing it a bit....
> > pinch flat would be a probability...I know when I was over 110, I had
> > the unwanted experience only too often of a puncture on my roadie
> > tires when psi got below 105....I'm now 82kgs and I still keep the
> > pressures up well over 110, usually 120 to 125 on 130psi rated
> > tires.....(punctures.... ummm what are they...I hear people mention
> > them....but I've forgotten what they are....)
>
> Ok, I'll bite... on 130psi rated tires how much pressure should I put
> into them?

There's some maths to determine 'ideal' pressures based on weight,
tyre size etc (it was published in one of the rags a few years ago
from memory), but I'd generally, at your weight, be running
100-120psi, on a 700x23 tyre, in the dry.

Jobst Brandt has some info here that may assist some of you:

http://yarchive.net/bike/tire_pressure.html

 

[TimC]

On 2007-03-07, Donga (aka Bruce)
was almost, but not quite, entirely unlike tea:
> On Mar 7, 4:06 pm, "Travis" <[email protected]> wrote:
>> I've just walked several km in 42 degree heat because my back tire
>> sidewall blew out... again. It happened two days ago as well.
....
> Has the wheel been set off-centre and the tire rubbing on a stay, or
> the brake block rubbing on the tire?

Broken stay that only flexes when you sit on the seat and can't peer
back to see what is rubbing?

--
TimC
You must realize that the computer has it in for you. The irrefutable
proof of this is that the computer always does what you tell it to do.

 

[TimC]

On 2007-03-07, DeF (aka Bruce)
was almost, but not quite, entirely unlike tea:
> 1: Rear wheel of MTB commuter. Slick tires that had perished with
> the help of over liberal application of chain lube. By pushing
> my finger nail along the tire, I could scrape the rubber off.
> Going down hill, about 35kph with 2.5yo in baby-seat. >BANG<
> back is fishtailing around but I manage to bring it to a halt
> without coming off.

And the 2.5Gyr (woah! I've been doing astronomy too long!) old was
all "daddy! Do that again!". And you were "bugger off!" in slightly
less polite terms.

> 2: Front wheel of my old tourer. Old tire with visible cracks due
> to hardening. I also over inflated the tire - >BANG< 3km walk
> home all barefoot with last km on gravel. Ouch.

How are the blisters healing? Why yes, I have done similar to that.
No, I don't know why I thought it a good idea to walk the 2km to the
beach barefooted on a 30 something degree day in a town where
footpaths were deemed unnecessary. I made it 3/4 of the way one way
before deciding to continue just to cool my feet down. Oh god, sand
can be like sandpaper! Heh.

The stupidity of youth.

--
TimC
Is it because do me reconcile my life that I say perhaps your plans
could have caused this that you are going through all this that you
came to me? --emacs doctor to TimC

 

[DeF]

TimC wrote:
> On 2007-03-07, DeF (aka Bruce)
> was almost, but not quite, entirely unlike tea:
>> 1: Rear wheel of MTB commuter. Slick tires that had perished with
>> the help of over liberal application of chain lube. By pushing
>> my finger nail along the tire, I could scrape the rubber off.
>> Going down hill, about 35kph with 2.5yo in baby-seat. >BANG<
>> back is fishtailing around but I manage to bring it to a halt
>> without coming off.
>
> And the 2.5Gyr (woah! I've been doing astronomy too long!) old was
> all "daddy! Do that again!". And you were "bugger off!" in slightly
> less polite terms.

Well, he used to say to me "go faster, go faster" all the time,
especially when we where going up hill. But when the tire blew,
he didn't do or say anything. Just sat there quietly, not in the
least perturbed. Meanwhile, my HR was getting up there.... He
was the same when I had a nose-to-nose altercation with a cage driver
after he'd undertaken me as I was turning right.

>
>> 2: Front wheel of my old tourer. Old tire with visible cracks due
>> to hardening. I also over inflated the tire - >BANG< 3km walk
>> home all barefoot with last km on gravel. Ouch.
>
> How are the blisters healing? Why yes, I have done similar to that.
> No, I don't know why I thought it a good idea to walk the 2km to the
> beach barefooted on a 30 something degree day in a town where
> footpaths were deemed unnecessary. I made it 3/4 of the way one way
> before deciding to continue just to cool my feet down. Oh god, sand
> can be like sandpaper! Heh.
>
> The stupidity of youth.

Well, the hair might be going gray but I've managed to hold on to
the stupidity aspect....

>

DeF.

--
e-mail: d.farrow@your finger.murdoch.edu.au
To reply, you'll have to remove your finger.