Worn-out Rims (related to "6 or 8 inches front disk?)

[Carl Fogel]

I see that the usual suspects are talking
about worn-out rims in the current thread
about "6 or 8 inches front disk?"

Since disk brakes rarely wear out rims,
perhaps anyone with pictures or details
about brake pads wearing out rims, how
the rims fail, and so forth might followup
here.

I have room on an otherwise useless web
site to post some emailed pictures of
failing rims, the grislier the better.

You all know who you are:

Tim McNamara
David Damerell
Jose Rizal
Pete Cresswell
Jobst Brandt
A. Muzi
Simon Brooke
Mike Latondresse
Matt O'Toole
Zog The Undeniable

Hopefully,

Carl Fogel

[Dion Dock]

It's fairly easy to wear out rims if you ride in the wet. My wife has worn
out 2-3 rims on her road bike, including at least one front. I seem to
destroy wheels (or buy new ones) before this happens.

The rim will actually bulge outward towards the top (the braking surface
becomes concave) when the tire is inflated. This is because the aluminum is
so thin, the air pressure actually causes it to bend. This is the opposite
of what most people expect: the rim does not get worn down and look like
parenthesis: )(. It looks more like this: \-/.

I've seen one failure of a front rim due to wear. The whole braking surface
broke away leaving a separate "hoop" of rim. I don't know how the rider
kept herself from crashing but she did.

Sorry, no pictures, this was before digital cameras were cheap and
plentiful.

-Dion

"Carl Fogel" <carl...@comcast.net> wrote in message
news:8bbde8fc.03110...@posting.google.com...

[Larry Silkaitis]

I have a worn out front rim from the mountain bike I ride to work. I rid in
lots of rain and grit. I noticed it when the brakes would rub the rim when
turning and getting off the seat when going up a hill. When I examined the
rim, it had worn through 180 degrees on one side and about 270 degrees on
the other side. I only run about 35 psig in the tyres.

Larry Silkaitis

"Carl Fogel" <carl...@comcast.net> wrote in message
news:8bbde8fc.03110...@posting.google.com...

[Carl Fogel]

carl...@comcast.net (Carl Fogel) wrote in message news:<8bbde8fc.03110...@posting.google.com>...

[snip original plea for failed-rim details and photos]

From: un smowler <unsm...@yahoo.com>
To: carl...@comcast.net
Subject: Worn Out Rims
Date: Tue, 11 Nov 2003 18:53:25 -0800 (PST)

Carl: I've been reading some of the RBT threads for
lunchtime diversion recently. I was surprised that
folks with much more cycling experience than mine
had never seen worn out rims before. Attached are
photos of a completely depreciated Mavic 221 rim.
Its life was just over 2 seasons of mountain biking
in southern Maine. For me a season is 6-7 months,
2 to 3 rides/week, 2-3 hours/ride. It's about typical
rim life for me, only the failure mode is unusual.
Usually I replace rims when they've gotten a major
ding, which becomes easier and easier to do as the
rim wears. This one somehow never got that abuse.
It failed while I was trying to seat a studded tire,
at about 60 psi. As an outcome, I have gotten a bit
quicker to replace rims when they start to flare out,
and keep ear protectors handy by the floor pump!

Feel free to quote me when you post the pics. Dave D

Dear Dave,

Here are your pictures of the failed rim:

http://home.comcast.net/~carlfogel/download/rim.jpg
http://home.comcast.net/~carlfogel/download/rimdetail.jpg

Thanks!

Carl Fogel