I have an '04 Specialized Expedition Sport. The last couple days of riding have introduced a very annoying clicking sound. It sounds like the left pedal is hitting on something whenever it's at its apex. I've looked and it's not even close to hitting anything. This didn't happen for the first week I rode the bike, just in the last couple of rides. No clicking when coasting or at any other point in the pedals travels other than the apex of the crank rotation. What should I be looking for?
Thanks in advance.