Friday, June 27, 2008

Problems can be opportunities!

Grace has found a new riding buddy in the form of another woman mountain bike racer, and they've been riding like crazy! They're getting along great, and having a bunch of fun. Just the other day, they went out and rode High Rocks (aka Ralph Stover) and found some new, technical trails. Riding some of these trails, Grace breaks a spoke in her rear wheel. When she tells me about this, I'm a little worried that she's getting into freeriding, something you don't necessarily want to do on an 18lb bike!

Well, turns out the broken spoke wasn't caused by her abuse, but instead by a mistake of mine... when we first got the wheels, her chain overshifted the big cog and wound up between the cassette and the spokes, which chewed up the spokes. The spoke that broke was one of those, and broke at the spot where the chain had chewed it up. So that's good news. Looking at the spokes, I realize I could just replace the damaged spokes, but what's the fun in that?

A little bit of research later, and an email to Larry at Bike Tools Etc., and I decided on the Sapim CX-Ray aero spokes. Aero spokes are ovalized to help them slice through the air, but on a mountain bike, the speeds aren't high enough for that to really be a benefit. No, the real reason for using the CX-Rays is that they are supposed to be incredibly strong, despite being among the lightest spokes out there. I guess the forming process which turns them into an aero spoke strengthens the metal. Either way, they've got a great rep, and will save almost 90 grams over the spokes I pulled out of the wheel!

When I rebuild the wheel, I'm also going to replace the Stan's rubber NoTubes strip with a valve stem and 3M Kapton tape, which should save about 50 grams. I also have a pair of new Kenda Klimax tires ready to go, which I fully expect won't get the Grace seal of approval, as they're only 345g and really have no real tread to speak of. Still, that's another 100g and it's at least worth a try!

With those changes, if I were to do them to the front wheel as well... we're nearing sub 18lbs on her bike... and aside from the Klimax tires, it should still be perfectly usable and reliable, not just a scale queen.

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