I've been trying to find a creaking noise that seems to be coming from the bottom bracket area, and I was wondering if there's some rule of thumb when it comes to replacing chain rings. My front shifts aren't as quick and positive as they used to be, and the large chain ring teeth seems to be slightly resembling hooks. Could this be the cause of the creaking It happens on both chain rings and only when I'm standing on the pedals.

I'll look at the BB, as well. I'm curious; how can I tell if I have a threaded or press-fit BB? It's a 2012 Madone 5.2.