Just got my bike from REI a bit less than two weeks ago and I'm encountering this strange creaking-like noise (probably not specific to the model as stated in the title) when I'm pedaling just a bit hard.
This happens when I'm on the larger front chain ring and in the 3 smallest rear cogs. (Oddly, it doesn't happen in any other gearing combinations). Also, this is not reproducible without load (i.e., if we're trying to replicate this on a bike repair stand... it won't happen). It would surely happen if someone were to sit in the bike and ride it around on those gear combinations.