Hi...I have cruised the forums and gotten a lot of useful info out of them, but I have encountered my first problem and can't find a solution or info about it.

I have been riding about 3 months now and just over the past 2 weeks, I have been hearing a popping sound at the bottom of the downstroke ONLY on the left side. When I am reaching the bottom of the downstroke on the left pedal, I will hear 2 pops (or creaks), but this is only while under pressure going up a hill or such. Switching to an easier gear solves the problem, but once I have to start putting pressure, or weight, back on the left side, the 2 pops start again. This is again only on the left side.

The LBS tightened the crank arm because it was a little loose and this seemed to make the problem slightly better, but it is not gone. It used to be silent with no noise whatsoever.

Could someone help a new cyclist out and perhaps give me a clue to what might be wrong and if it is something I can fix? Much thanks in advance!