I've put about 15 miles on my new Trek 7.3 FX since I got it on Friday. I have what I'm sure is a very Noob question: many times when I shift gears, especially the rear, I get a loud clanking or grinding type sound from the gears that persists until I shift again. Sometimes it takes two or three tries to get into a smooth, quiet gear.
Is it possible that my rear derailer needs an adjustment already? I read through Sheldon Brown's column on the topic but am very reluctant to make any adjustments until I know what's causing the noise. My fear is that my uber-Clyde size (370 lbs.) is putting pressure on the drivetrain and causing the noise. I will not be able to get the bike back to the LBS until next weekend, and am not sure if I should be riding it in the meantime. I apologize if this is a common question - I'm just worried about my new bike. Any thoughts?