I have spent quite a bit of time recently getting my bike running as perfectly as I can for my forthcoming adventure. Part of this has been to try and get rid of all the irritating little noises (creaks and rattles) as these are likely to become very annoying on 10 days of consecutive riding. These are the things that I have found:
Gear cable adjusters: Both gear cables have in-line adjusters which I noticed when riding over bumpy ground rattled against each other, this was solved by slightly shortening the outer cable and re-routing so that they no longer touch each other.
Saddle: When pedalling hard I noticed that the saddle creaked, it took a while to track this down as it sounded like the sound was coming from lower down. My saddle was still the original Giant saddle that came with the bike, this has now been replaced with a Fizik Arione CX, no more creaking.
Pedals: When out of the saddle and climbing hills I noted that my chainset would click on the down stroke, I decided the best way to solve this was to torque everything to the correct settings, but I was unable to tighten the pedals enough with a standard spanner so I bought myself a workshop pedal spanner so I could get the pedals nice and tight, once I did the noise disappeared all together.
Headset: Again when out of the saddle and climbing the headset would click slightly, this was again simple a matter of tightening everything up to the right torque settings, noise gone!
Water bottle holders: These would rattle, never quite worked out why but changed both from Giant branded ones to Elite Custom Race bottle cages and the noise was gone.
So now my bike is pretty much silent apart from the usual chain on sprocket sound, but at least all the annoying creaks and rattles are no more…