Trimmer striking chain link fence

[HT2005]

I've noticed that when I ride my motorized bike, sometimes I hear a sound that can only be described as something like a trimmer string hitting a chain link fence. Have any of you had this same issue? It's happened about 4 times already in about 60 miles of riding. This is about 5 trips of riding.

[Norco John]

The ends of the pins on the chain rubbing on something? Chain slapping the chainguard?

[Cabinfever1977]

chain slapping the left clutch cover or fender.

[HT2005]

I think it might be the tensioner for the chain vibrating. Oh well, not a big deal. I just went out for a 7 mile ride and only happened once.