Thursday, June 08, 2006

Clang, clink, clunk

Blue Clouds overhead


So, I had my bike in a million or so pieces on Tuesday night for a good solid cleaning. You could eat off the rear cassette when I was done with it (it didn't really want to go back together, but I won out in the end). It took about 3 hours to fully clean the bike, but afterwards, it was gleaming and changing gears like never before.

That brings us to tonight... this has happened before (twice), but I thought it was due to needing adjustments, anyway, my bike has a NASTY habit of making EARTH SHATTERING CLANKING noises on very steep climbs. The noise is bad enough itself, but at the time, it also causes the chaing to slip (jump, skip, whatever) and negate forward momentum (not to mention put fear into me that something is about to snap). So, I made certain that my bike was adjusted perfectly today, and started the climb up Sycamore... 1/4 of the way up, it began the clank, clink, clunk trick. Only on the top of my pedal stroke, and only every 10 or so revolutions (clearly there is a link in the chain that is screwing up with a tooth on the chainring). I shifted down to my lowest gear (by this time I was stopped due to the 24% grade), and returned to the bottom of the hill to start over.
I began (again) to climb, making sure that everything was in alignment, and I was in my easiest gear (usually I am in the middle chainring and middle cog to start). I got about 1/3 of the way up before the clanking began - it was at this point that children ran in terror from the blue smoke that begin to erupt from my mouth... 25% grade, and I lost all momentum (in fact, the last clunk screwed me up so much that I began to go backwards down the hill). Clearly, there is a problem... I will have to investigate.

I didn't get to finish the ride up the hill (out of fear of ruining the drivetrain), but I did get the full GPS report of the hill. Here is the elevation and grade diagrams (click the pics to get a bigger view).


Elevation



Grade



Summary
So, it appears that Sycamore isn't as 'burly' a hill as it was touted to be. It has sections in the mid 20s for grade, but the average over the 0.6 mile climb is about 14% (those sections of 24% and 25% are rough though). I need to try that hill in the 'Dirty Dozen' that has a 30+% grade (just for kicks).

- VG

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