I wonder if anyone can suggest any reason why I might be getting a regular clicking (two to each crank revolution, at the same place each time) from the crank/BB area of my bike. I understand these things can be difficult to diagnose, but just hoping I can be guided down the most likely paths.
I recently took the bike to a shop and they said the only thing they could do was replace the free wheel, which I found odd as the sound is unmistakably coming from the front end of the drive train. I can't spot anything visually wrong as I turn the crank, but the clicking only happens in the second chainring, not the first or third. I've had a good look at this chainring and it doesn't look excessively worn, although there is the odd tooth that is clearly much more pointed that the rest, to the point of resembling knives. Also the chain runs clear of the front derailleur, so I'm guessing that can't play a part in this.
Could it be that the chainring just needs replacing? Any other suggestions gratefully received! Thanks.