Jeff Wills

Yep, could have been worse. Mine let go with a bang:
http://home.comcast.net/~jeff_wills/rites2005/pages/rites042.htm

Fortunately it was on the straight & level and I was able to walk the bike to downtown Gresham and wait for my wife to ride home and fetch the van. Nowadays I replace the rim before it gets too worn.

Jeff
------------------------------------------------------------

> Message: 26
> Date: Mon, 4 Apr 2011 08:48:54 -0700
> From: John Fortes
> To: obra
> Subject: Re: [OBRA Chat] Rim brake surface splitting
> Message-ID:
> Content-Type: text/plain; charset="iso-8859-1"
>
> Thanks a bunch for all the replies. This was my first post to the list in
> my several years of following. You all are awesome. We were going down
> hill on surfer springs road in Corvallis area and I blazed by him while he
> was still descending. Someone else in our group was able to come to a stop
> on the hill and make sure he was OK. He ended up getting a ride home with
> his family. I don't believe that he crashed which is a miracle. It could
> have been much worse.

Dan H

That looks like plain old brake pad wear. Every time the brakes touch
the rim a little bit of it wears away until it gets so thin it blows
out. I have examples on hand to show customers. Wet weather riding
accelerates the wear which is why we have training wheels and race day
wheels.
BTW, rim blow outs never happen at a convenient time.
If the braking surface is starting to get concave, it's time to think
about replacing the rim. They don't last forever. Most newer rims have
a wear indicator in the form of a hole that appears or a a groove that
dissapears.
That faure goes to maintainamce. As a race mechanic, I'm constantly
amazed at the neglected and worn out stuff people will race on. It not
only could ruin your day but also the day of anyone caught up in the
wreck it could cause. That's why all forms of motor racing have safety
inspections.
Take care of your stuff folks. The skin you save might be mine!

Dan Houghton
Southwest Bicycle, LLC
3605 SW Multnomah Blvd
503-246-0333
www.swbicycle.com

On Apr 3, 2011, at 8:42 PM, John Fortes wrote:

> A guy further back on my group ride today had to drop out due to the
> rim splitting right at the brake surface. He emailed me this photo
> (link below). I have my theories but haven't had a chance to get a
> look at what his bike and brake pads look like. Have any of you
> seen this? Any ideas of the cause? Thanks OBRA family!
>
> https://picasaweb.google.com/lh/photo/lfT_Z0nWXD8YvBrhumG5DQ?feat=directlink
> _______________________________________________
> OBRA mailing list
> obra@list.obra.org
> http://list.obra.org/mailman/listinfo/obra
> Unsubscribe: obra-unsubscribe@list.obra.org

John Bravard

Disc brakes in the rain are the way to go.

>
> On 4/3/2011 8:42 PM, John Fortes wrote:
>>
>> A guy further back on my group ride today had to drop out due to the rim splitting right at the brake surface. He emailed me this photo (link below). I have my theories but haven't had a chance to get a look at what his bike and brake pads look like. Have any of you seen this? Any ideas of the cause? Thanks OBRA family!
>>
>> https://picasaweb.google.com/lh/photo/lfT_Z0nWXD8YvBrhumG5DQ?feat=directlink
>>
>> _______________________________________________
>> OBRA mailing list
>> obra@list.obra.org
>> http://list.obra.org/mailman/listinfo/obra
>> Unsubscribe: obra-unsubscribe@list.obra.org
>
> _______________________________________________
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> obra@list.obra.org
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> Unsubscribe: obra-unsubscribe@list.obra.org

Rick Johnson

Time to replace is generally before you get to this point -

Rick Johnson
Bend Oregon

On 4/3/2011 8:42 PM, John Fortes wrote:
> A guy further back on my group ride today had to drop out due to the
> rim splitting right at the brake surface. He emailed me this photo
> (link below). I have my theories but haven't had a chance to get a
> look at what his bike and brake pads look like. Have any of you seen
> this? Any ideas of the cause? Thanks OBRA family!
>
> https://picasaweb.google.com/lh/photo/lfT_Z0nWXD8YvBrhumG5DQ?feat=directlink
>
>
> _______________________________________________
> OBRA mailing list
> obra@list.obra.org
> http://list.obra.org/mailman/listinfo/obra
> Unsubscribe: obra-unsubscribe@list.obra.org

John Fortes

Thanks a bunch for all the replies. This was my first post to the list in
my several years of following. You all are awesome. We were going down
hill on surfer springs road in Corvallis area and I blazed by him while he
was still descending. Someone else in our group was able to come to a stop
on the hill and make sure he was OK. He ended up getting a ride home with
his family. I don't believe that he crashed which is a miracle. It could
have been much worse.

-
John

On Mon, Apr 4, 2011 at 8:29 AM, NW Cyclist wrote:

> Appears the rim is worn out. All rims will wear out eventaully, and this
> is a potentailly very dangerous situation, imagine if you'd bee going 40 mph
> down a hill and the rim failed...not good. There have been several stories
> of rim failures on the OBRA list, so he is not alone.
>
> There is a very simple preventive maintenance measure that you can
> perform to extend the life of your rims: Inspect the brake pads for tiny
> rocks, pieces of metal, etc that may have embedded in the brake pad surface
> and remove them, I use a small screwdriver or the corner of a utility
> knife. Once embedded in the brake surface, these items will greatly
> accelerate the rate of rim wear. Sometimes I use a 320 grit sand paper and
> lightly brush brake-pad surface, the tiny pieces of rock or metal will show
> up much better so you can pick them out.
>
> On Mon, Apr 4, 2011 at 6:24 AM, wrote:
>
>> Looks like wear; the brake pads slowly wear away the aluminum on the rim
>> (this is significantly accelerated when the bike is ridden in wet
>> conditions). Pretty much all modern rims will have some kind of
>> wear-indicator on the braking surface (in most cases a dot machined into the
>> sidewall). Once this wear indicator disappears, the rim has become so worn
>> and so thin that it's time to replace the rim. Also, in many cases, even
>> without a wear indicator, a dangerously worn rim can be indentified by the
>> sidewalls bowing outward slightly as they approach the tire (oft refered to
>> as a "death valley").
>>
>> --
>> Aaron "Rambo" Harrison
>>
>> ----- Original Message -----
>> From: "John Fortes"
>> To: obra@list.obra.org
>> Sent: Sunday, April 3, 2011 8:42:58 PM
>> Subject: [OBRA Chat] Rim brake surface splitting
>>
>>
>>
>> A guy further back on my group ride today had to drop out due to the rim
>> splitting right at the brake surface. He emailed me this photo (link
>> below). I have my theories but haven't had a chance to get a look at what
>> his bike and brake pads look like. Have any of you seen this? Any ideas of
>> the cause? Thanks OBRA family!
>>
>>
>>
>> https://picasaweb.google.com/lh/photo/lfT_Z0nWXD8YvBrhumG5DQ?feat=directlink
>> _______________________________________________
>> OBRA mailing list
>> obra@list.obra.org
>> http://list.obra.org/mailman/listinfo/obra
>> Unsubscribe: obra-unsubscribe@list.obra.org
>> _______________________________________________
>> OBRA mailing list
>> obra@list.obra.org
>> http://list.obra.org/mailman/listinfo/obra
>> Unsubscribe: obra-unsubscribe@list.obra.org
>>
>
>

NW Cyclist

Appears the rim is worn out. All rims will wear out eventaully, and this is
a potentailly very dangerous situation, imagine if you'd bee going 40 mph
down a hill and the rim failed...not good. There have been several stories
of rim failures on the OBRA list, so he is not alone.

There is a very simple preventive maintenance measure that you can
perform to extend the life of your rims: Inspect the brake pads for tiny
rocks, pieces of metal, etc that may have embedded in the brake pad surface
and remove them, I use a small screwdriver or the corner of a utility
knife. Once embedded in the brake surface, these items will greatly
accelerate the rate of rim wear. Sometimes I use a 320 grit sand paper and
lightly brush brake-pad surface, the tiny pieces of rock or metal will show
up much better so you can pick them out.

On Mon, Apr 4, 2011 at 6:24 AM, wrote:

> Looks like wear; the brake pads slowly wear away the aluminum on the rim
> (this is significantly accelerated when the bike is ridden in wet
> conditions). Pretty much all modern rims will have some kind of
> wear-indicator on the braking surface (in most cases a dot machined into the
> sidewall). Once this wear indicator disappears, the rim has become so worn
> and so thin that it's time to replace the rim. Also, in many cases, even
> without a wear indicator, a dangerously worn rim can be indentified by the
> sidewalls bowing outward slightly as they approach the tire (oft refered to
> as a "death valley").
>
> --
> Aaron "Rambo" Harrison
>
> ----- Original Message -----
> From: "John Fortes"
> To: obra@list.obra.org
> Sent: Sunday, April 3, 2011 8:42:58 PM
> Subject: [OBRA Chat] Rim brake surface splitting
>
>
>
> A guy further back on my group ride today had to drop out due to the rim
> splitting right at the brake surface. He emailed me this photo (link
> below). I have my theories but haven't had a chance to get a look at what
> his bike and brake pads look like. Have any of you seen this? Any ideas of
> the cause? Thanks OBRA family!
>
>
>
> https://picasaweb.google.com/lh/photo/lfT_Z0nWXD8YvBrhumG5DQ?feat=directlink
> _______________________________________________
> OBRA mailing list
> obra@list.obra.org
> http://list.obra.org/mailman/listinfo/obra
> Unsubscribe: obra-unsubscribe@list.obra.org
> _______________________________________________
> OBRA mailing list
> obra@list.obra.org
> http://list.obra.org/mailman/listinfo/obra
> Unsubscribe: obra-unsubscribe@list.obra.org
>

john

Rim wear is accelerated (obviously) not by wet conditions alone but be road
grit, carried by the water..

I have found that Kool stop pads with their little scraper nose, do a better
job at getting the water/grit off the rim and from being captured under the
pad...

in lieu of kool stop I have cut pad so it leads with a 'V' ,
that seperates the water/grit around the pad..

This is also the reason for "training" wheels / rims. 32 or 36 h box
section rims use to be ~ $10 a rim. Simply tape the new rim (same erd) to
the old wheel/rim and transfer the spokes/nipples across. usually about a
30 minute process... less if you only do the transfer and take to bike
shop for final tension and true.

On Mon, Apr 4, 2011 at 6:24 AM, wrote:

> Looks like wear; the brake pads slowly wear away the aluminum on the rim
> (this is significantly accelerated when the bike is ridden in wet
> conditions). Pretty much all modern rims will have some kind of
> wear-indicator on the braking surface (in most cases a dot machined into the
> sidewall). Once this wear indicator disappears, the rim has become so worn
> and so thin that it's time to replace the rim. Also, in many cases, even
> without a wear indicator, a dangerously worn rim can be indentified by the
> sidewalls bowing outward slightly as they approach the tire (oft refered to
> as a "death valley").
>
> --
> Aaron "Rambo" Harrison
>
> ----- Original Message -----
> From: "John Fortes"
> To: obra@list.obra.org
> Sent: Sunday, April 3, 2011 8:42:58 PM
> Subject: [OBRA Chat] Rim brake surface splitting
>
>
>
> A guy further back on my group ride today had to drop out due to the rim
> splitting right at the brake surface. He emailed me this photo (link
> below). I have my theories but haven't had a chance to get a look at what
> his bike and brake pads look like. Have any of you seen this? Any ideas of
> the cause? Thanks OBRA family!
>
>
>
> https://picasaweb.google.com/lh/photo/lfT_Z0nWXD8YvBrhumG5DQ?feat=directlink
> _______________________________________________
> OBRA mailing list
> obra@list.obra.org
> http://list.obra.org/mailman/listinfo/obra
> Unsubscribe: obra-unsubscribe@list.obra.org
> _______________________________________________
> OBRA mailing list
> obra@list.obra.org
>

rambobikeman@frontier.com

Looks like wear; the brake pads slowly wear away the aluminum on the rim (this is significantly accelerated when the bike is ridden in wet conditions). Pretty much all modern rims will have some kind of wear-indicator on the braking surface (in most cases a dot machined into the sidewall). Once this wear indicator disappears, the rim has become so worn and so thin that it's time to replace the rim. Also, in many cases, even without a wear indicator, a dangerously worn rim can be indentified by the sidewalls bowing outward slightly as they approach the tire (oft refered to as a "death valley").

--
Aaron "Rambo" Harrison

----- Original Message -----
From: "John Fortes"
To: obra@list.obra.org
Sent: Sunday, April 3, 2011 8:42:58 PM
Subject: [OBRA Chat] Rim brake surface splitting

A guy further back on my group ride today had to drop out due to the rim splitting right at the brake surface.  He emailed me this photo (link below).  I have my theories but haven't had a chance to get a look at what his bike and brake pads look like.  Have any of you seen this?  Any ideas of the cause?  Thanks OBRA family!

https://picasaweb.google.com/lh/photo/lfT_Z0nWXD8YvBrhumG5DQ?feat=directlink
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OBRA mailing list
obra@list.obra.org
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Unsubscribe: obra-unsubscribe@list.obra.org

Kevin

Worn out rims, due to brake wear. Pads wear out, and in time so do the rims.
Many rims have a built in recessed marking to indicate when rims get too thin
and are no longer safe to ride.

Kevin

+++++++++++++++++++++++++++++++++++++++++++++++++++++
What is happening in Kevin's corner of the bike world?
http://the-whir-of-spokes-in-air.blogspot.com
+++++++++++++++++++++++++++++++++++++++++++++++++++++

________________________________
From: John Fortes
To: obra@list.obra.org
Sent: Sun, April 3, 2011 8:42:58 PM
Subject: [OBRA Chat] Rim brake surface splitting

A guy further back on my group ride today had to drop out due to the rim
splitting right at the brake surface. He emailed me this photo (link below). I
have my theories but haven't had a chance to get a look at what his bike and
brake pads look like. Have any of you seen this? Any ideas of the cause?
Thanks OBRA family!

https://picasaweb.google.com/lh/photo/lfT_Z0nWXD8YvBrhumG5DQ?feat=directlink

John Fortes

A guy further back on my group ride today had to drop out due to the rim
splitting right at the brake surface. He emailed me this photo (link
below). I have my theories but haven't had a chance to get a look at what
his bike and brake pads look like. Have any of you seen this? Any ideas of
the cause? Thanks OBRA family!

https://picasaweb.google.com/lh/photo/lfT_Z0nWXD8YvBrhumG5DQ?feat=directlink