I need a hand here, for things to check on my wife's bike. We just recently bought her a Trek 3700 (woman's). It's been working wonderfully, except recently it's started to make this steady clunking noise when it's being ridden. If you're the rider, you can feel it in the seat on your butt.
A couple of facts about it:
- It happens steadily, whether you're pedaling or not (something to do with the wheel I'd have to imagine, right?)
- It does not happen unless a person's weight is applied to the seat (free spinning the front wheel or pedaling the back without anyone on it produces nothing)
- I'm somewhat (read: very) ignorant, but it doesn't appear to be the chain being loose, as it seems as taut as the chain on my Trek which doesn't have them problem.
Watching the bike as she rides it, I can't see anything hitting the frame anywhere. Brakes are well aligned, chain is situated in place well, etc. But if someone has something specifically for me to look at, that would help a lot.