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Mavic 217 rim failure.
My ride is a Cannondale M700, mostly tuned to street/commute riding.
After two pair of bad wheels[1], got a pair built at Bicycle Works, here
in Napa, CA. With ~750 miles on 'em, the build was great (Bob stands
behind his work, and I'd recommend him).
Day after a 36 miler, I'm 2.2 miles from home, on flat surface streets,
just rounded a corner, ~17 MPH, as there's a loud "pop" similar to spoke
breakage and feel the rim rubbing my pads. Rear wheel.
Dismount, check for broken/loose spokes. None.
Hrm. What's this?
The rim itself has blown out, tearing within the sidewall. ASII art
cross-section of damage:
\ /
\ /
| /
| /
\ /
\__________/
Note that the rim sidewall's actually blown out, not deformed at the
top. The damaged region is about 3-4" in length. There's no visible
rim scoring indicating abrasive damage. The bike shop confirms that the
rims don't feel "grooved" or otherwise worn. I'll try getting pics at
some point if possible.
The wheel is a Mavic 217, ~26" diam, 17mm wide, hard-anodized. This was
apparently discontinued around 1997.
I picked up the wheels, new, October, 2003. Didn't ride much for most
of a year, they've got < 800mi total, most in the past few weeks.
Tires are slicks, Road Warrior 26x1.25, rated to 85 PSI. Yes, I
overinflate to ~95-100 PSI. My own out-of-fighting-trim weight is 260.
My riding is wholly on-road. Recent rides in the 20-50 mi range,
through Napa valley. No off road. Minimal bad weather. Precautions on
any foreseen impacts (debris, chuckholes, curbs, speed bumps).
So, back to Bicycle Works. They say they'll to work out a deal with
Mavic. In fairness, the wheel is out of warranty (one year, passed Oct.
2004), but has clearly failed at about 10% of anticipated life.
Word back is Mavic asked "did it have slicks" and is rejecting any
replacement on the grounds that the rim is rated to 85 PSI, and my
95-100 is beyond its design strength. Which I feel is pretty damne
bogus (more below). Long discussion with Bob, who respects not wanting
to deal with companies who shaft their customers, but really can't
recommend a comperable quality product in the price range.
So:
- Is anyone else seeing catastrophic rim failure similar to this?
Googling both Web and Usenet shows no clear pattern. Which would
tend to support the idea that this was a chance manufacture defect.
- Any recommendations for dealing with Mavic? I'm itching to get back
in the saddle, and have a new wheel on order, but would appreciate a
break on the ~$70 for a new rim. Particularly as I'm going with
Mavic, despite strong misgivings.
- Any alternate rim recommendations? I'm on a serious budget, so
nothing fancy -- comperable pricing to what I've got. I've had
serial bad luck with wheels. I'm also pretty conservative from a
materials standpoint.
- Any comments on overpressure issues? Experience pro or con?
More on pressure: I really can't believe I'm the only guy who'se
running high pressure, particularly on slicks, on a bike. It's a cheap
and effective performance enhancement, and it's something I've done for
years (decades) with no adverse effects in the past. I find the
prospect of a 90% lifetime reduction for a 16% pressure increase rather
frightening -- the dynamic pressure load on wheels has to be
considerably higher under normal riding with various road and debris
impacts, and I'd really hate to think I'm putting my life on the line
for a < 20% engineering tolerance.
I'm shooting a copy of this posting to Mavic to see what they have to
say.
Peace.
- ---------------------
Notes:
1. Mike's Bikes, Palo Alto and San Rafael (California) stores. Both
were wibbly within weeks of purchase. The set from San Rafael
required tuning within the first 20 miles, when I realized that the
hub was loose within the rear wheel. Been a long-time (30 years)
Mike's customer, the shop's _definitely gone downhill. Both wheels
ate spokes, typically 1-3 needing replacement after a ride.
- --
Karsten M. Self <[email hidden]> http://kmself.home.netcom.com/
What Part of "Gestalt" don't you understand?
Jeff Waugh: Can't see the trees for the trees...
- http://zgp.org/pipermail/linux-elitists/2004-January/008588.html
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