Im also having this problem on my 2007 Fuji Crosstown 2.0 Hybrid. The bike was originally bought as a commuter, but I got layed off back in Oct. Since then I've joined a bike club, and am putting a lot of miles on it weekly. I'm also a Clyde. I weigh about 300 lbs. (dropping quickly though). I used to play football in high school, and also have very strong legs. This causes me have a tendency to over torque instead od spinning going up the grades. Is this really bad for the gears? I try spinning, but I just feel more comfortabe in a higher gear, and using a little more leg power when climbing. Is this a bad habit I need to try to get myself out of? Spinning in a lower gear just doesn't feel comfortable. Also, I haven't made the transition to clipless pedals, and still use platforms. I'm also getting that clanking noise when climbing, and downshifting. I usually stay in the saddle when climbing, but my legs are now strong enough again where I'm starting to stand on the pedals while starting a climb. I was on a 40 mi. ride yesterday, and a few times when I stood up on the pedals the clanking was so bad it sounded like the steel frame was going to split in two?? Does anyone think this problem might just be a RD adjustment, or have I over torqued where the cassette might be bad? I looked at the chainring, and it seems fine. No wear, and the teeth look good. I plan on taking it to my LBS for a tune-up (I get free lifetime tune-ups), but they're closed today for Presidents Day, and they're still on winter hours, and will be closed tomorrow too.

I'm not sure exactly what you mean by a clanking noise but I'll offer this anyway.

If you tend to mash on the pedals instead of spin, especially at your weight, you will tend to wear out chains quicker than the average cyclist. If you don't replace the chain before it gets worn too badly, you'll likely cause very quick wear of the teeth on the cassette. Eventually, when the wear gets bad enough you'll find that whenever you try to apply a lot of force that the chain slips on the cassette. This generally will only occur in the gears most often used or in the really small cogs (11 or 12 tooth).

If you are not experiencing slippage, then you likely do not have a cassette problem yet though that doesn't mean your chain isn't worn out. A worn chain, however, should not cause any clanking noises. An out-of-adjustment rear derailler is a far more likely source of noise. Deraillers go out of adjustment with use as the housing liner, pivots, and ratchets break in/wear. The fix is usually a simple adjustment to the cable tension for the rear derailler assuming the limits screws were set properly to begin with.

Thanks. I'll take it to the LBS on Wed. and have them look at it. I'm hoping its just a RD adjustment. On a further note, the bike is not even a year old, and I have only approximately 2,000 miles on it. Most of it has been put on within the last 2 months, in the cold and snowy conditions.

Have you relubed your chain during those 2000 wet miles? If not, you likely have a few stiff links which will create noise all by themselves in addition to making shifting sluggish.

Yeah, just lubed a couple days ago actually. Finish Line Cross Country Wet.