Split rim

Quoted message said:

On the ride home from work my rear brakes were rubbing against the rim.
I was going to straighten out the wheel when I got home, but no amount
of truing is going to fix this:
http://www.magma.ca/~ronmck/photo/split-rim.jpg

Anybody have this happen before? The rim is a Mavic T261 with maybe
22000 km of road use on it.

Very common on wheels used for commuting, particularly in the rain. The
sidewalls simply get worn away to the point they can no longer withstand the
pressure from the tube and blow out. Many newer rims now have embedded wear
indicators in the sidewalls; when the rim is worn to the bottom of the
indicator, time to replace.

--Mike Jacoubowsky
Chain Reaction Bicycles
www.ChainReaction.com
Redwood City & Los Altos, CA USA

"Ron McKinnon" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Well this is a first for me.

On the ride home from work my rear brakes were rubbing against the rim.
I was going to straighten out the wheel when I got home, but no amount
of truing is going to fix this:
http://www.magma.ca/~ronmck/photo/split-rim.jpg

Anybody have this happen before? The rim is a Mavic T261 with maybe
22000 km of road use on it.

I don't recall hitting any big bumps lately. I patched a flat last
Thursday but the rim seemed fine then.

Oh well, time for a new wheel. Pity it couldn't have lasted another
month though. I would have had all winter to make a new one. Now I'll
have to rush to get those last few weeks of riding in.

Cheers.
Ron.

A few weeks ago a spoke broke on the rear wheel of my MTB, which caused the
wheel, probably fairly warped to begin with, to flop back and forth, which
caused the rear brake to hang up on the rim, which took some forceful
banging on with a large rock to break loose, before I could limp home.

Anyway, the LBS sold me a 'double-walled' wheel, which they said should
prevent wheel-warping in future.

rms

Ron McKinnon said:

Well this is a first for me.

On the ride home from work my rear brakes were rubbing against the rim.
I was going to straighten out the wheel when I got home, but no amount
of truing is going to fix this:
http://www.magma.ca/~ronmck/photo/split-rim.jpg

Anybody have this happen before? The rim is a Mavic T261 with maybe
22000 km of road use on it.

I don't recall hitting any big bumps lately. I patched a flat last
Thursday but the rim seemed fine then.

Oh well, time for a new wheel. Pity it couldn't have lasted another
month though. I would have had all winter to make a new one. Now I'll
have to rush to get those last few weeks of riding in.

Cheers.
Ron.

You're lucky -- you made it home -- in one piece... Seriously, if you
put enough miles on a bike in the rain the rims will eventually fail
(2200km isn't a surprisingly short amount). You want to check old rims
periodically because they can fail in a much less benign manner. If you
lay a straightedge along the brake track (radial direction) you can see
how concave the sidewall is, which give you some idea of how worn they
are. Typical rim walls are 1.5mm new, 0.5mm when getting ready to go. If
you don't have a caliper or rim wear indicators, use a straightedge and
be conservative -- particularly on a front wheel.

Ron McKinnon said:

Well this is a first for me.

On the ride home from work my rear brakes were rubbing against the rim.
I was going to straighten out the wheel when I got home, but no amount
of truing is going to fix this:
http://www.magma.ca/~ronmck/photo/split-rim.jpg

Anybody have this happen before? The rim is a Mavic T261 with maybe
22000 km of road use on it.

I don't recall hitting any big bumps lately. I patched a flat last
Thursday but the rim seemed fine then.

Doesn't look like the result of an impact, but rather just wearing out
due to the braking surface becoming too thin. Does the braking surface
have a distinct concave feel to it indicating that the surface has been
worn down by the brake pads? Here's a picture of a rim I recently
replaced since I was no longer comfortable with the thickness of the
rim sidewall. Note the gap between the rim sidewall and the hex wrench
held up against it:
http://home.comcast.net/~prathman/RimWear.jpg

That rim had about five times the mileage of yours, but the critical
factor is the amount of braking that's been done, especially in wet
conditions where abrasive particles get between the pads and the rim
sidewall surface.

Ron McKinnon said:

Well this is a first for me.

On the ride home from work my rear brakes were rubbing against the rim.
I was going to straighten out the wheel when I got home, but no amount
of truing is going to fix this:
http://www.magma.ca/~ronmck/photo/split-rim.jpg

Anybody have this happen before? The rim is a Mavic T261 with maybe
22000 km of road use on it.

I don't recall hitting any big bumps lately. I patched a flat last
Thursday but the rim seemed fine then.

Not being able to see the outside wall of the rim, it's just a guess,
but I would expect this to be an indication that the braking surfaces
are so worn that the rim needed to be replaced anyway. IMO, that's
the single biggest drawback of the aluminum rim with conventional
brakes; it wears out.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Ron McKinnon said:

Well this is a first for me.

On the ride home from work my rear brakes were rubbing against the rim.
I was going to straighten out the wheel when I got home, but no amount
of truing is going to fix this:
http://www.magma.ca/~ronmck/photo/split-rim.jpg

Anybody have this happen before? The rim is a Mavic T261 with maybe
22000 km of road use on it.

Sure, brakes made rim sidewall so thin, tire pressure made it split-

Quoted message said:

I don't recall hitting any big bumps lately. I patched a flat last
Thursday but the rim seemed fine then.

Oh well, time for a new wheel. Pity it couldn't have lasted another
month though. I would have had all winter to make a new one. Now I'll
have to rush to get those last few weeks of riding in.

Cheers.
Ron.

"Ron McKinnon" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Well this is a first for me.

On the ride home from work my rear brakes were rubbing against the rim.
I was going to straighten out the wheel when I got home, but no amount
of truing is going to fix this:
http://www.magma.ca/~ronmck/photo/split-rim.jpg

Anybody have this happen before? The rim is a Mavic T261 with maybe
22000 km of road use on it.

Like this?

http://www.geocities.com/cpetersky/rim2.JPG

That was with a Mavic MA3, "A high quality and affordable classic rim",
after about 4000 miles on it. Everyone on RBT said this is what happens when
you commute in the PNW in the rain.

--
Warm Regards,

Claire Petersky
http://www.bicyclemeditations.org/
See the books I've set free at: http://bookcrossing.com/referral/Cpetersky

Quoted message said:

http://www.geocities.com/cpetersky/rim2.JPG

That was with a Mavic MA3, "A high quality and affordable classic rim",
after about 4000 miles on it. Everyone on RBT said this is what happens
when you commute in the PNW in the rain.

"Everyone" is right.

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

"Claire Petersky" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"Ron McKinnon" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Well this is a first for me.

On the ride home from work my rear brakes were rubbing against the rim.
I was going to straighten out the wheel when I got home, but no amount
of truing is going to fix this:
http://www.magma.ca/~ronmck/photo/split-rim.jpg

Anybody have this happen before? The rim is a Mavic T261 with maybe
22000 km of road use on it.

Like this?

http://www.geocities.com/cpetersky/rim2.JPG

That was with a Mavic MA3, "A high quality and affordable classic rim",
after about 4000 miles on it. Everyone on RBT said this is what happens
when you commute in the PNW in the rain.

--
Warm Regards,

Claire Petersky
http://www.bicyclemeditations.org/
See the books I've set free at: http://bookcrossing.com/referral/Cpetersky

In rec.bicycles.misc Claire Petersky said:

Like this?

http://www.geocities.com/cpetersky/rim2.JPG

Oooh, nasty. Which reminds me, I need to get a spring caliper or
something so I can measure how much braking track I have left. My front
wheel is starting to look really concave along there.

Quoted message said:

That was with a Mavic MA3, "A high quality and affordable classic rim",
after about 4000 miles on it. Everyone on RBT said this is what happens when
you commute in the PNW in the rain.

:-/ Pretty much. 4000 miles does seem like a really short lifespan
though. I've gotten about 8000 from my Alex Adventurer so far. I
already have another identical rim to swap onto the wheel when the time
comes.

I've considered moving to a front disc brake setup, but I'd have to get
a new dynohub wheel built with the disc version of my hub, in addition
to the brake and fork, which seems like too much hassle to me.

--
Dane Buson - [email hidden]
"I didn't know it was impossible when I did it."

peter said:

Doesn't look like the result of an impact, but rather just wearing out
due to the braking surface becoming too thin. Does the braking surface
have a distinct concave feel to it indicating that the surface has been
worn down by the brake pads? Here's a picture of a rim I recently
replaced since I was no longer comfortable with the thickness of the
rim sidewall. Note the gap between the rim sidewall and the hex wrench
held up against it:
http://home.comcast.net/~prathman/RimWear.jpg

I think you're probably right. In the past my rims needed replacing
prior to the edge wearing due to other factors such as warping. This
was a solidly-build wheel that lasted longer, and hence it probably
wore through as you said.

Thanks everyone for the info. I'll keep a closer eye on wear from now
on.

Ron McKinnon said:

Well this is a first for me.

On the ride home from work my rear brakes were rubbing against the rim.
I was going to straighten out the wheel when I got home, but no amount
of truing is going to fix this:
http://www.magma.ca/~ronmck/photo/split-rim.jpg

Anybody have this happen before? The rim is a Mavic T261 with maybe
22000 km of road use on it.

Yep. Mine let go with a bang:
http://home.pacifier.com/~jwills/rites2005/pages/rites042.htm

The sidewall looks pretty concave. It was time for a new rim anyway.

Jeff

Jeff Wills said:

Quoted message said:

Well this is a first for me.

Quoted message said:

Quoted message said:

On the ride home from work my rear brakes were rubbing against the
rim. I was going to straighten out the wheel when I got home, but
no amount of truing is going to fix this:

http://www.magma.ca/~ronmck/photo/split-rim.jpg

Quoted message said:

Quoted message said:

Anybody have this happen before? The rim is a Mavic T261 with
maybe 22000 km of road use on it.

Quoted message said:

Yep. Mine let go with a bang:

http://home.pacifier.com/~jwills/rites2005/pages/rites042.htm

Quoted message said:

The sidewall looks pretty concave. It was time for a new rim anyway.

Before you throw the rim in the aluminum recycle bin, how about sawing
a 2-3 inch section out of it where it didn't break, sand paper the
ends smooth and show us a picture with a metal ruler in the
foreground... or measure the wall thickness at cross section where the
sidewall failure occurred, but a picture just the same.

Jobst Brandt

Quoted message said:

http://home.pacifier.com/~jwills/rites2005/pages/rites042.htm

Quoted message said:

The sidewall looks pretty concave. It was time for a new rim anyway.

Before you throw the rim in the aluminum recycle bin, how about sawing
a 2-3 inch section out of it where it didn't break, sand paper the
ends smooth and show us a picture with a metal ruler in the
foreground... or measure the wall thickness at cross section where the
sidewall failure occurred, but a picture just the same.

Sorry, Jobst- next time I'll remember.

Jeff

In article <[email hidden]>,

Quoted message said:

Before you throw the rim in the aluminum recycle bin, how about sawing
a 2-3 inch section out of it where it didn't break, sand paper the
ends smooth and show us a picture with a metal ruler in the
foreground... or measure the wall thickness at cross section where the
sidewall failure occurred, but a picture just the same.

Perhaps something like this: http://tinyurl.com/wtvqa

This rim didn't fail, but I decided I had gotten my money's worth from
it and didn't relish the prospect of a sudden failure on the road. A
post-mortem showed that the wall at its thinnest was about 0.5 mm thick.

--
Bill Bushnell
http://pobox.com/~bushnell/

Ron McKinnon said:

http://www.magma.ca/~ronmck/photo/split-rim.jpg

Anybody have this happen before? The rim is a Mavic T261 with maybe
22000 km of road use on it.

That was a common failure for Mavic 261 rims, even with much lower
mileage. They were made from unusually brittle alloy and had unusually
thin sidewalls.

Chalo

Bill Bushnell said:

Quoted message said:

Before you throw the rim in the aluminum recycle bin, how about
sawing a 2-3 inch section out of it where it didn't break, sand
paper the ends smooth and show us a picture with a metal ruler in
the foreground... or measure the wall thickness at cross section
where the sidewall failure occurred, but a picture just the same.

Quoted message said:

Perhaps something like this:

http://tinyurl.com/wtvqa

Quoted message said:

This rim didn't fail, but I decided I had gotten my money's worth
from it and didn't relish the prospect of a sudden failure on the
road. A postmortem showed that the wall at its thinnest was about
0.5 mm thick.

Next time sand the ends smooth so that the wall thickness is readily
visible. I have rims like that and measured the bead-to-bead width
and found it to be unchanged from a new rim. I also was down to 0.5mm
but no failure.

Jobst Brandt

Ron McKinnon said:

On the ride home from work my rear brakes were rubbing against the rim.
I was going to straighten out the wheel when I got home, but no amount
of truing is going to fix this:
http://www.magma.ca/~ronmck/photo/split-rim.jpg

Anybody have this happen before? The rim is a Mavic T261 with maybe
22000 km of road use on it.

Was this a typo? 22,000 km (14,000 or so miles) sounds like it's time
for an honorable rim retirement. If, as some have read it, it was
only 2,200 km, that seems awfully low to me.

Pat

Email address works as is.

Patrick Lamb said:

Ron McKinnon said:

On the ride home from work my rear brakes were rubbing against the rim.
I was going to straighten out the wheel when I got home, but no amount
of truing is going to fix this:
http://www.magma.ca/~ronmck/photo/split-rim.jpg

Anybody have this happen before? The rim is a Mavic T261 with maybe
22000 km of road use on it.

Was this a typo? 22,000 km (14,000 or so miles) sounds like it's time
for an honorable rim retirement. If, as some have read it, it was
only 2,200 km, that seems awfully low to me.

Pat

Email address works as is.

Dear Pat,

Rim life can vary considerably according to conditions.

My daily 15-mile ride involves almost no braking, so I've never worn
out a rim in over 100,000 miles.

I'm pretty sure that most posters are like you and brake far more
often and in far worse conditions, so your rims lead lives that are
nasty, brutish, and short.

Some posters have mentioned wearing out rims in what seems awfully low
to you (and flabbergasting to me). Here's a link to a post from a
fellow who wore out a rim in two 6-7 month seasons of Maine mtb
riding, 2-3 rides per week, 2-3 hours per ride:

http://groups.google.com/group/rec.bicycles.tech/msg/de7fd7b0c6dd27f3

His figures work out to 200 to 550 hours of mtb riding, which is
getting down near the 2,200 km figure that we both find startling, but
I gather that severe braking in muddy conditions can do such terrible
things to rims.

Cheers,

Carl Fogel

Patrick Lamb said:

Was this a typo? 22,000 km (14,000 or so miles) sounds like it's time
for an honorable rim retirement. If, as some have read it, it was
only 2,200 km, that seems awfully low to me.

Pat

No, no typo. By contrast, my racing bike (the busted rim was on my
touring bike) which gets mostly fair-weather riding shows no
appreciable signs of wear at the rims.