Wednesday, August 30, 2006

The new road bike is slowly but surely being sorted out. Last Saturday I took the bike out for a 50 mile ride with the road triathlon crew. Not fifteen miles into the ride I got a flat. First ride, first flat. Not a good omen. The rest of the ride was uneventful, though I suffered mightily on the return. I passed a number of riders coming out of Nicasio, and as I slogged through the final hills I prayed that I wouldn't get overtaken. (I didn't.)

I noticed some shifting problems on the ride, so I took the bike into the shop last night. I thought the problem was a sticky link. The mechanic thought it was a problem with cable tension, so he fiddled around with the rear derailleur tension screw for quite a while. Once he was satisfied everything was working properly he gave it to a second mechanic for a quick QC. The second mechanic quickly realized what the real problem was: a bad cassette.

When I bought the bike I asked for a larger rear cog in the back to replace the standard 12-23 cassette. For those unfamiliar with bicycle drivetrains, "12-23" refers to the number of teeth on the smallest and largest cogs on the cassette. Larger cogs (or smaller chainrings in the front) reduce the effort required to turn the rear wheel. Moving to a larger cog is similar to downshifting in a car. In both cases the new gear combination allows the rider (or driver) to climb hills more easily.

In the rush to get the bike out of the shop, the mechanic had replaced the 12-23 cassette with a 12-25 cassette. Unfortunately, he installed a nine-speed cassette instead of a ten-speed cassette. Since my rear derailleur is designed to move between ten gears and not nine, the bike was never going to shift properly with the nine-speed cassette.

In the end I got a shiny new 12-27 ten-speed cassette. I thanked the mechanic for his help and rushed out the door to go for a quick ride in the fading light.

I bought a used pair of Crank Brothers Eggbeater pedals from my friend Robbie. They're compact and lightweight, and I thought they might work well with the road bike. Now I've never had a problem with pedals falling off the bike. I'm not even sure how that would happen, since if anything the act of pedaling ought to tighten the pedals. But last night off they came. Five times.

By the fifth time I gave up. I threw the recalcitrant pedal in the Camelback and practiced one-legged drills all the way across the Golden Gate Bridge and back to the car.

0 Comments:

Post a Comment

<< Home