Mountain riding and rim life

I was surprised to see the first replacement set of rims I had to buy
for my bike last only a year and a half (after the original ones that
came with it lasted ten years).

My original set were Ritchey Vantage (on a Bridgestone MTB). When a
mechanic pointed out the cupping wear in the rim (from braking) and said
the strength was significantly compromised, I bought a pair of Mavic
517's (silver, not anodized). That was in the spring of 2003.

After my braking became very herky jerky this fall, I was amazed when a
mechanic pointed out that my rear rim had significant cupping wear
(front had a lot of wear, too) and was actually beginning to weaken and
flair ever so slightly outward in spots (hence the grabby brakes).

(He related that if the rim failed bad enough, it could crease, split,
start to fly apart and chew my leg to bits. ô¿Ô¬ !!)

That was only a year and a half after putting them on my bike. Not
wanting to continue with Mavics, I shopped around, but I concluded that
Mavics really are good rims, so I now have a new set of 717 (the very
same as 517's as far as I can tell - just a new model number).

So now I'm wondering ............... Last year, I changed the amount of
mountain riding that I do significantly. I mean, that's about the only
place I ride anymore (steep mountain rides). So, a question to other
mountain riders out there; does the increased braking required in
mountain riding (and it is *significantly* more than riding on flats or
even on hills) actually cause accelerated rim wear - to that magnitude
(10 years vs. 1½ years)? How often do any of you find yourself needing
new rims? Any recommendations for a longer lasting rim?

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Chuck Anderson • Boulder, CO
http://www.CycleTourist.com
Integrity is obvious.
The lack of it is common.
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