Good question, during the mid to late-80's Mavic's hard-annodizing was just a little too hard. This lead to really brittle rims and clincher rims that would blow out with little forewarning. This was caused by the pressure exerted by the tire on the rim bead. It wasn't as much of a problem with the road rims, but I've seen this happen to both MA-40's and Open-4's. Thought I did never see it happen to a "T" series rim. The second sidewall blowout problem I've seen happened the sew-up rims like the ones described earlier. What would happen is the "hill" parts of the rim would wear and since the "valley" sections never showed wear, and added to the brittleness of the rims would cause parts of the "hills" to break out of the rim leaving holes in the breaking surface. I've been wary of their rims for a long time, though I've had fine luck with them myself beyond 280's and 330's being too light for my riding. I try to use Wolber or Weinmann for my classic bikes and Sun for moderns. I'm sure other industry folk have similar stories, since I'm sure it wasn't just a Seattle thing. enjoy, Brandon"monkeyman"Ives
"Nobody can do everything, but if everybody did something everything would get done." Gil Scott-Heron
On Mon, 9 Jul 2001 Sid_Smith@baxter.com wrote:
> Monkeyman, Have you been mounting Wilderness AT's on your wheelsets?
> What's with the "exploding rims"?
> re: the wear pattern, I have the same pattern that showed up on a set of
> Open 4CD's after a long ride in the rain on some insanely steep hills
> (well, we were riding home from a hillclimb race!) Nothing further amiss
> with the wheels in over 3,000 mi since. On the same wheelset a year
> earlier I did pop a spoke (DT doublebutted), I was boneheaded enough to
> turn a corner and jump out of the saddle into a steep hill in way too large
> a gear. Naturally I popped a drive side spoke, rear wheel. I've learned
> to avoid such manuevers, my wheels thank me.
> My rimsets are mostly Mavic; Open 4, Reflex, SUP Open Pro, GL330, Paris
> Roubaix; there are a few superlight sets with Fiamme Ergals (usually 36
> spoke). I'd think that Ergals would be about as fragile as you get, but so
> far no troubles.
> Pleased to contibute,
> Sid, in sunny Chicago contemplating my after work ride, Smith