Bam! Rims blow out this morning

[Claire]

Yesterday, I got out the bike to ride to work, and the rear tire was
flat. Not having much spare time, I took the bus instead of dealing
with it.

This morning, I made sure I had the time. I pulled off the wheel and
then the tire and tube, and then did the morning meditation of feeling
for what might be poking through the tire. I pulled out various tiny
pieces of glass, gravel, and wire, but nothing seemed to have
penetrated all the way through. I did a more cursory review of the
tube, and didn't find anything obvious.

Since at this point I was running low on time, I decided to set the
tube aside for later repair and grab another tube. I put the new tube
and tire on, and pumped it up. I had just reached the rated pressure of
105 when I heard bam!. I thought, "oh ****, I didn't have the tube
seated properly". I found another yet another tube to put on the bike,
but upon examination, became clear that the rims had blown out in two
places.

Do you think that the rim blew out with the initial "bam!", and I just
didn't notice it? I was in such a tizzy about being increasingly late
for work, it's certainly possible. And was the initial flat because
there was something wrong with the rims in the first place?

And then -- I had this wheel built and put on about a year ago. So,
although there was some wear on the rims, it wasn't a deep groove.
There's probably only about 3500 - 4000 miles on the wheel. Was this
blow-out a fault of the wheel builder? I'm going to call him this
morning and have a talk with him, anyway.

I'm sure glad, if the rims were going to blow out, they did so in my
hands in the garage, as opposed to while I was screaming down Kamber
Road at 45 mph in this morning's pouring rain. I'm also glad that the
ride I'm leading this weekend is a tandem ride, and I'm not dependent
on this bike as a ride leader.

Warm Regards,


Claire Petersky
Home of the meditative cyclist:
http://home.earthlink.net/~cpetersky/Welcome.htm
Personal page: http://www.geocities.com/cpetersky/

I'm doing the Big Climb for my friend Dena! See:
http://www.active.com/donations/campaign_public.cfm?key=cpetersky

 

[Peter]

Claire wrote:
> Yesterday, I got out the bike to ride to work, and the rear tire was
> flat. ...
> I did a more cursory review of the tube, and didn't find anything obvious.

Did you find the hole in the tube? Was it a small pinhole, a longer
gash, twin "snakebites"? And where was it located - under the tread,
by the sidewall, or along the rim side of the tube?
>
> Since at this point I was running low on time, I decided to set the
> tube aside for later repair and grab another tube. I put the new tube
> and tire on, and pumped it up. I had just reached the rated pressure of
> 105 when I heard bam!. I thought, "oh ****, I didn't have the tube
> seated properly". I found another yet another tube to put on the bike,
> but upon examination, became clear that the rims had blown out in two
> places.
>
> Do you think that the rim blew out with the initial "bam!", and I just
> didn't notice it?

Presumably the rim failed and therefore no longer properly held the
tire bead in place. That let part of the tube escape the confines of
the rim and tire resulting in rapid expansion and rupture of the tube.

> I was in such a tizzy about being increasingly late
> for work, it's certainly possible. And was the initial flat because
> there was something wrong with the rims in the first place?

The hole in the tube might yield some clues.
>
> And then -- I had this wheel built and put on about a year ago. So,
> although there was some wear on the rims, it wasn't a deep groove.
> There's probably only about 3500 - 4000 miles on the wheel. Was this
> blow-out a fault of the wheel builder?

There may have been a defect in the rim, but I can't think of anything
the wheel builder would be likely to do that would result in premature
rim failure. Were there signs that a piece of grit may have created
a particularly bad scratch on the rim braking surface?

 

[[email protected]]

Claire Petersky writes:

> Since at this point I was running low on time, I decided to set the
> tube aside for later repair and grab another tube. I put the new
> tube and tire on, and pumped it up. I had just reached the rated
> pressure of 105 when I heard bam!. I thought, "oh ****, I didn't
> have the tube seated properly". I found another yet another tube to
> put on the bike, but upon examination, became clear that the rims
> had blown out in two places.

> Do you think that the rim blew out with the initial "bam!", and I
> just didn't notice it? I was in such a tizzy about being
> increasingly late for work, it's certainly possible. And was the
> initial flat because there was something wrong with the rims in the
> first place?

I am unclear on what you mean by "the rim had blown out." What
failed? How was this apparent? What is equally unclear is whether
this rim failure was the cause of the initial flat and how that was
not apparent when you first patched the tire.

> And then -- I had this wheel built and put on about a year ago. So,
> although there was some wear on the rims, it wasn't a deep groove.
> There's probably only about 3500 - 4000 miles on the wheel. Was
> this blow-out a fault of the wheel builder? I'm going to call him
> this morning and have a talk with him, anyway.

Wait a minute! When did this occur? You say "And then..." meaning
subsequently, but a year ago? This is less clear as it unfolds.

> I'm sure glad, if the rims were going to blow out, they did so in my
> hands in the garage, as opposed to while I was screaming down Kamber
> Road at 45 mph in this morning's pouring rain. I'm also glad that
> the ride I'm leading this weekend is a tandem ride, and I'm not
> dependent on this bike as a ride leader.

I think there is a present, past, and future tense problem here as well.
Pleas clarify.

Jobst Brandt
[email protected]

 

[Zog The Undeniable]

Claire wrote:
> Yesterday, I got out the bike to ride to work, and the rear tire was
> flat. Not having much spare time, I took the bus instead of dealing
> with it.
>
> This morning, I made sure I had the time. I pulled off the wheel and
> then the tire and tube, and then did the morning meditation of feeling
> for what might be poking through the tire. I pulled out various tiny
> pieces of glass, gravel, and wire, but nothing seemed to have
> penetrated all the way through. I did a more cursory review of the
> tube, and didn't find anything obvious.
>
> Since at this point I was running low on time, I decided to set the
> tube aside for later repair and grab another tube. I put the new tube
> and tire on, and pumped it up. I had just reached the rated pressure of
> 105 when I heard bam!. I thought, "oh ****, I didn't have the tube
> seated properly". I found another yet another tube to put on the bike,
> but upon examination, became clear that the rims had blown out in two
> places.
>
> Do you think that the rim blew out with the initial "bam!", and I just
> didn't notice it? I was in such a tizzy about being increasingly late
> for work, it's certainly possible. And was the initial flat because
> there was something wrong with the rims in the first place?
>
> And then -- I had this wheel built and put on about a year ago. So,
> although there was some wear on the rims, it wasn't a deep groove.
> There's probably only about 3500 - 4000 miles on the wheel. Was this
> blow-out a fault of the wheel builder? I'm going to call him this
> morning and have a talk with him, anyway.
>
> I'm sure glad, if the rims were going to blow out, they did so in my
> hands in the garage, as opposed to while I was screaming down Kamber
> Road at 45 mph in this morning's pouring rain. I'm also glad that the
> ride I'm leading this weekend is a tandem ride, and I'm not dependent
> on this bike as a ride leader.

Well, they usually go when being inflated as this is when they hit their
highest pressure (excluding long descents while braking).

Can you post a link to a photo of the damage? It could be worn out
sidewalls from braking, or it could be cracking due to hard anodising.

 

[Sandy]

<[email protected]> a écrit dans le message de :
news:[email protected]...
>
>> And then -- I had this wheel built and put on about a year ago.
>
> Wait a minute! When did this occur? You say "And then..." meaning
> subsequently, but a year ago? This is less clear as it unfolds.

You lack of mastery of common conversational English is apparent here. The
meaning of "and then" would be clear to you, were that not an inadequacy on
your part. Pedantry is not a virtue.

> I think there is a present, past, and future tense problem here as well.

You are predicting, describing the past, and commenting on the current
status of the author's syntax ? You are completely unclear here, in your
own syntax and grammar. Is your glass house well ventilated by fast moving
pebbles ?

> Pleas clarify.

Finally, don't take former politicos too seriously - there IS a time to put
an "e" on the end of some words, such as "pleasE". But not potato.

Relying on your excellent good humour, and that you remain silent on
subjects you have inadequately grasped.
--
Bonne route,

Sandy
Verneuil-sur-Seine FR

 

[Mike Latondresse]

"Claire" <[email protected]> wrote in
news:[email protected]:

>
> And then -- I had this wheel built and put on about a year ago.
> So, although there was some wear on the rims, it wasn't a deep
> groove. There's probably only about 3500 - 4000 miles on the
> wheel. Was this blow-out a fault of the wheel builder? I'm going
> to call him this morning and have a talk with him, anyway.
>
Claire, that is more than the mileage I usually get out of a rim before
it starts to bulge....the Pacific NW rainy season really wears them
away.

 

[[email protected]]

Mike Latondresse wrote:
> "Claire" <[email protected]> wrote in
> news:[email protected]:
>
> >
> > And then -- I had this wheel built and put on about a year ago.
> > So, although there was some wear on the rims, it wasn't a deep
> > groove. There's probably only about 3500 - 4000 miles on the
> > wheel. Was this blow-out a fault of the wheel builder? I'm going
> > to call him this morning and have a talk with him, anyway.
> >
> Claire, that is more than the mileage I usually get out of a rim
before
> it starts to bulge....the Pacific NW rainy season really wears them
> away.

Moreover, it would be helpful to know what kind of rim it was to begin
with. (Syntactically speaking- tell us what kind of rim it is. I'll
presume that the rim did not magically morph through years of use.
Hmmm... alliteration, too.)

I have a Sun CR-18 rim that has survived many more miles than that,
including several Pacific Northwest winters. However, my winter mileage
has dropped lately due to my lack of employment.

Jeff

 

[Sheldon Brown]

Claire wrote:

> Do you think that the rim blew out with the initial "bam!", and I just
> didn't notice it?

Yes.

> I was in such a tizzy about being increasingly late
> for work, it's certainly possible. And was the initial flat because
> there was something wrong with the rims in the first place?

Sounds like it was worn out. Usually they give you warning by bulging
out a bit in one section, which you'll feel as a pulsing/grab when you
use the brake.

> And then -- I had this wheel built and put on about a year ago. So,
> although there was some wear on the rims, it wasn't a deep groove.
> There's probably only about 3500 - 4000 miles on the wheel. Was this
> blow-out a fault of the wheel builder?

Absolutely not! Nothing a wheelbuilder could or would do would cause
this. It's caused by wear from the brake shoes. Some brake shoes are
much worse for this than others. I particularly recommend Kool Stop
salmon for this reason (also because of superior braking and longevity.)

Sheldon "Not The Wheelbuilder's Fault" Brown
+--------------------------------------------------------------+
| The holy passion of Friendship is of so sweet and steady |
| and loyal and enduring a nature that it will last through |
| a whole lifetime, if not asked to lend money. --Mark Twain |
+--------------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

 

[Frank Miles]

In article <[email protected]>,
Claire <[email protected]> wrote:

[snip sordid flat story]

> I found another yet another tube to put on the bike,
>but upon examination, became clear that the rims had blown out in two
>places.

Ahhh... the _rim_? It wasn't the tire unseating, and the rim blowing
out from the gap? Guess we'll have to assume that is the case. Presumably
this is the 'sidewall' of the rim, where the brake shoes (slowly) wear
down the wall thickness.

>Do you think that the rim blew out with the initial "bam!", and I just
>didn't notice it? I was in such a tizzy about being increasingly late
>for work, it's certainly possible. And was the initial flat because
>there was something wrong with the rims in the first place?

It seems unlikely. Once the sidewall is compromised, the wheel rapidly
loses its "trueness". In fact, rims usually seem to become less true
as the sidewall gets really thin (perhaps due to my imperfect spoke tension
matching).

>And then -- I had this wheel built and put on about a year ago. So,
>although there was some wear on the rims, it wasn't a deep groove.
>There's probably only about 3500 - 4000 miles on the wheel. Was this
>blow-out a fault of the wheel builder? I'm going to call him this
>morning and have a talk with him, anyway.

The wheel-builder didn't do anything wrong. You've been commuting in
our wet gritty weather, which wears rims down fast. One thing I've
learned to do is to periodically take a stout thumbnail -- or perhaps
a not-too-sharp slotted screwdriver to places in the rim sidewall that
might be closes to wearing through (especially if there are gouges)
and see if I can dent or press the nail/screwdriver through the wall
of the rim. And yes, I have detected rims getting too thin this way.
I've occasionally hack-sawed the rims after removing the spokes, and
confirmed how thin they were becoming.

It does seem that 3500-4500 is quite low for this to occur.
If you (or your husband) are interested, you might cut the rim apart
to see if this was really what was going on. Were these bleeding-edge
lightweight rims? If so, you might get heavier rims if you're going to
be using them in nasty gritty wet riding. Someone else recommended
the Sun CR-18; I'd second that.

>I'm sure glad, if the rims were going to blow out, they did so in my
>hands in the garage, as opposed to while I was screaming down Kamber
>Road at 45 mph in this morning's pouring rain.

Yes! And exactly why checking is a Good Idea.

[snip]

-frank
--

 

[Werehatrack]

On 4 Feb 2005 09:08:57 -0800, "Claire" <[email protected]> may have
said:
> I had just reached the rated pressure of
>105 when I heard bam!. I thought, "oh ****, I didn't have the tube
>seated properly". I found another yet another tube to put on the bike,
>but upon examination, became clear that the rims had blown out in two
>places.

As in, lateral separation of the flange from the rest of the rim,
presumably? This is almost always the result of cumulative wear from
the brakes.

>Do you think that the rim blew out with the initial "bam!", and I just
>didn't notice it?

Likely.

>I was in such a tizzy about being increasingly late
>for work, it's certainly possible. And was the initial flat because
>there was something wrong with the rims in the first place?

Hard to say. Maybe. Were both failures on the flange which was away
from you when you were working with the tube? If so, then it's
possible that you missed the fault.

>And then -- I had this wheel built and put on about a year ago. So,
>although there was some wear on the rims, it wasn't a deep groove.
>There's probably only about 3500 - 4000 miles on the wheel. Was this
>blow-out a fault of the wheel builder? I'm going to call him this
>morning and have a talk with him, anyway.

The wheelbuilder might have commented on the condition of the rim at
the time if it seemed excessively worn, but there's nothing that he
could have done to prevent a wear-based failure...or to cause one, for
that matter.

Had the rim begun to split while the bike was last being ridden, there
would have been a pulsation in the brakes as the pads hit the bulge.
Since I assume that you'd have mentioned this if it was present, it is
further assumed that no pulsation was present, ergo the rim failed
when pumped. As you posit, the fact that it occurred in the garage
and not on a fast commute run is a mitzvah.

--
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.

 

[Matt O'Toole]

Frank Miles wrote:

> The wheel-builder didn't do anything wrong. You've been commuting in
> our wet gritty weather, which wears rims down fast.

Yup.

> One thing I've
> learned to do is to periodically take a stout thumbnail -- or perhaps
> a not-too-sharp slotted screwdriver to places in the rim sidewall that
> might be closes to wearing through (especially if there are gouges)
> and see if I can dent or press the nail/screwdriver through the wall
> of the rim. And yes, I have detected rims getting too thin this way.
> I've occasionally hack-sawed the rims after removing the spokes, and
> confirmed how thin they were becoming.

A better way is to measure the rim with a pair of calipers. Most rim
manufacturers give a spec for minimum sidewall thickness, determined by
measuring total width. If not, sometimes you can find the overall dimensions on
the web or in a brochure. In general, 0.5mm sidewall thickness is getting too
thin.

Many newer rims have a wear dimple somewhere in the sidewall. I believe this is
required by German law.

> It does seem that 3500-4500 is quite low for this to occur.
> If you (or your husband) are interested, you might cut the rim apart
> to see if this was really what was going on. Were these bleeding-edge
> lightweight rims? If so, you might get heavier rims if you're going
> to
> be using them in nasty gritty wet riding. Someone else recommended
> the Sun CR-18; I'd second that.

It's not unusual for MTB rims to wear at such rates. I know riders who went
through them every six months, before disk brakes came out.

Good brake pads really do make a difference. Shimano pads machine your rims
like a lathe. Avoid them at all costs if you ride in wet conditions. Kool-Stop
are much, much better.

The upside to rim replacement is that the stouter ones tend to be cheaper.

>> I'm sure glad, if the rims were going to blow out, they did so in my
>> hands in the garage, as opposed to while I was screaming down Kamber
>> Road at 45 mph in this morning's pouring rain.

> Yes! And exactly why checking is a Good Idea.

Absolutely.

To all the professional mechanics out there -- how many of you check this as
part of a standard tune up?

Matt O.

 

[Marvin]

Matt O'Toole wrote:
> Frank Miles wrote:
>

> Many newer rims have a wear dimple somewhere in the sidewall. I
believe this is
> required by German law.
>
> > It does seem that 3500-4500 is quite low for this to occur.

Depends so heavily on conditions and use you can hardly say. It's
certainly low-normal though.

> >> I'm sure glad, if the rims were going to blow out, they did so in
my
> >> hands in the garage, as opposed to while I was screaming down
Kamber
> >> Road at 45 mph in this morning's pouring rain.
>
> > Yes! And exactly why checking is a Good Idea.
>
> Absolutely.
>
> To all the professional mechanics out there -- how many of you check
this as
> part of a standard tune up?
>
> Matt O.

Certainly do, lightweight rims are pretty much regarded as consumables
these days. Usually it's more obvious to check whether the rim surface
is getting concave and/or heavily scored. The other, more advanced
symptom is a slight bulge in the rim which you can check for by
spinning the wheel and looking at both brake block clearances at once
(or riding the bike and finding the brakes grab).

I have to admit to having mistaken bulging rims for untrue wheels
before and been briefly confused as to how the wheel trued itself when
I let the tyre down. Must've happened on National Brainfade Day

 

[Mike Jacoubowsky/Chain Reaction Bicycles]

> Since at this point I was running low on time, I decided to set the
> tube aside for later repair and grab another tube. I put the new tube
> and tire on, and pumped it up. I had just reached the rated pressure of
> 105 when I heard bam!. I thought, "oh ****, I didn't have the tube
> seated properly". I found another yet another tube to put on the bike,
> but upon examination, became clear that the rims had blown out in two
> places.
>
> Do you think that the rim blew out with the initial "bam!", and I just
> didn't notice it? I was in such a tizzy about being increasingly late
> for work, it's certainly possible. And was the initial flat because
> there was something wrong with the rims in the first place?

Claire: This is your commute bike, correct? One that you probably ride when
the weather's not always pleasant? The reason I ask is because we often see
"exploding" rims on commute bikes, and virtually never on bikes ridden
recreationally. The reason is because commute bikes are more likely to be
ridden when the weather's bad, which means you're grinding down the
sidewalls as your brakes & rims pick up guck from the roadway. It's
literally like putting a file or nasty sandpaper to your rims, every time
you brake. And on a commute bike, you might be using your brakes quite a bit
more, because you're often in traffic (and taking the most-direct route,
rather than the scenic option that avoids most stop signs, stop lights and
other traffic-related reasons for using your brakes).

There's nothing wrong with the way your wheel(s) was built, and nothing,
short of disc brakes, that will eliminate the issue. You do, however, want
to avoid really light rims because they'll have a thinner sidewall (which
gets worn out more readily). Also, many newer rims now have wear indicators
built into them... basically, little carved-out spots which indicate, when
the rim is worn down to the bottom of them, that it's time to replace.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
IMBA, BikesBelong, NBDA member

"Claire" <[email protected]> wrote in message
news:[email protected]...
> Yesterday, I got out the bike to ride to work, and the rear tire was
> flat. Not having much spare time, I took the bus instead of dealing
> with it.
>
> This morning, I made sure I had the time. I pulled off the wheel and
> then the tire and tube, and then did the morning meditation of feeling
> for what might be poking through the tire. I pulled out various tiny
> pieces of glass, gravel, and wire, but nothing seemed to have
> penetrated all the way through. I did a more cursory review of the
> tube, and didn't find anything obvious.
>
> Since at this point I was running low on time, I decided to set the
> tube aside for later repair and grab another tube. I put the new tube
> and tire on, and pumped it up. I had just reached the rated pressure of
> 105 when I heard bam!. I thought, "oh ****, I didn't have the tube
> seated properly". I found another yet another tube to put on the bike,
> but upon examination, became clear that the rims had blown out in two
> places.
>
> Do you think that the rim blew out with the initial "bam!", and I just
> didn't notice it? I was in such a tizzy about being increasingly late
> for work, it's certainly possible. And was the initial flat because
> there was something wrong with the rims in the first place?
>
> And then -- I had this wheel built and put on about a year ago. So,
> although there was some wear on the rims, it wasn't a deep groove.
> There's probably only about 3500 - 4000 miles on the wheel. Was this
> blow-out a fault of the wheel builder? I'm going to call him this
> morning and have a talk with him, anyway.
>
> I'm sure glad, if the rims were going to blow out, they did so in my
> hands in the garage, as opposed to while I was screaming down Kamber
> Road at 45 mph in this morning's pouring rain. I'm also glad that the
> ride I'm leading this weekend is a tandem ride, and I'm not dependent
> on this bike as a ride leader.
>
> Warm Regards,
>
>
> Claire Petersky
> Home of the meditative cyclist:
> http://home.earthlink.net/~cpetersky/Welcome.htm
> Personal page: http://www.geocities.com/cpetersky/
>
> I'm doing the Big Climb for my friend Dena! See:
> http://www.active.com/donations/campaign_public.cfm?key=cpetersky
>

 

[Mike Latondresse]

[email protected] wrote in
news:[email protected]:

>
> Mike Latondresse wrote:
>> Claire, that is more than the mileage I usually get out of a rim
> before
>> it starts to bulge....the Pacific NW rainy season really wears
>> them away.
>
> Moreover, it would be helpful to know what kind of rim it was to
> begin with. (Syntactically speaking- tell us what kind of rim it
> is. I'll presume that the rim did not magically morph through
> years of use. Hmmm... alliteration, too.)

It has been a variety of rims over the years from the absolutely
cheapest Campy ones to Muscova 80 which went last fall. Interestingly
looking at it all the give in the rim was on one side.
>
> I have a Sun CR-18 rim that has survived many more miles than
> that, including several Pacific Northwest winters. However, my
> winter mileage has dropped lately due to my lack of employment.
>
I commute just a hair over 40k/day and it was the front wheel on my
fixie, my only brake however most of the others were on a bike with 2
brakes.

 

[Tom Sherman]

Sandy wrote:

> ...Pedantry is not a virtue....

Yes it is.

--
Tom Sherman - Earth

 

[Claire Petersky]

"Peter" <[email protected]> wrote in message
news:[email protected]...

> Did you find the hole in the tube? Was it a small pinhole, a longer
> gash, twin "snakebites"? And where was it located - under the tread,
> by the sidewall, or along the rim side of the tube?

I have not looked more closely for the hole in the original tube. It was not
readily apparent.

> Were there signs that a piece of grit may have created
> a particularly bad scratch on the rim braking surface?

No.


--
Warm Regards,

Claire Petersky
Home of the meditative cyclist:
http://home.earthlink.net/~cpetersky/Welcome.htm
Personal page: http://www.geocities.com/cpetersky/

I'm doing the Big Climb for my friend Dena! See:
http://www.active.com/donations/campaign_public.cfm?key=cpetersky

 

[Claire Petersky]

<[email protected]> wrote in message
news:[email protected]...

> I think there is a present, past, and future tense problem here as well.

Approximately one year ago, entire wheel replaced.
One day ago, upon return from a long trip, I notice that the rear tire is
flat.
This morning, I replaced the tube, and the rims blew out.


--
Warm Regards,

Claire Petersky
Home of the meditative cyclist:
http://home.earthlink.net/~cpetersky/Welcome.htm
Personal page: http://www.geocities.com/cpetersky/

I'm doing the Big Climb for my friend Dena! See:
http://www.active.com/donations/campaign_public.cfm?key=cpetersky

 

[Claire Petersky]

"Zog The Undeniable" <[email protected]> wrote in message
news:4203b9ac.0@entanet...

> Can you post a link to a photo of the damage? It could be worn out
> sidewalls from braking, or it could be cracking due to hard anodising.

Photos here: http://www.geocities.com/cpetersky/rims.html

Sorry the pictures are not ideal. I will put up perhaps better ones later,
but I have many pressing demands on me this evening. Thank you for your
interest and advice.


--
Warm Regards,

Claire Petersky
Home of the meditative cyclist:
http://home.earthlink.net/~cpetersky/Welcome.htm
Personal page: http://www.geocities.com/cpetersky/

I'm doing the Big Climb for my friend Dena! See:
http://www.active.com/donations/campaign_public.cfm?key=cpetersky

 

[[email protected]]

Claire Petersky writes:

>> Can you post a link to a photo of the damage? It could be worn out
>> sidewalls from braking, or it could be cracking due to hard anodizing.

Photos here: http://www.geocities.com/cpetersky/rims.html

> Sorry the pictures are not ideal. I will put up perhaps better ones
> later, but I have many pressing demands on me this evening. Thank
> you for your interest and advice.

That helps, but from what I see, this is not a mere weak (worn) rim
failure but one of bottoming the rim on the road with a soft tire.
Since it didn't occur as an explosion while riding (the initial flat)
I believe it was a chafing failure of the tube running in the damaged
rim. This is the kind of flaw that causes a bang as you noticed when
fully inflating the tire as you described.

The reason I suspect this scenario is that the bend in the rim bead is
too short and has a severe outward curl to have occurred from tire
pressure. It looks like a crack induced by a snake bite ding in the
rim. A pressure failure would separate the bead over a long segment
without curling the rim edge.

Jobst Brandt
[email protected]

 

[Mark Hickey]

"Claire Petersky" <[email protected]> wrote:

><[email protected]> wrote in message
>news:[email protected]...
>
>> I think there is a present, past, and future tense problem here as well.
>
>Approximately one year ago, entire wheel replaced.
>One day ago, upon return from a long trip, I notice that the rear tire is
>flat.
>This morning, I replaced the tube, and the rims blew out.

Ahhhhh, but what about tomorrow?

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $695 ti frame