Missing O-Ring

[NAKID]

I am pretty good about chain maintenance, usually cleaning and lubing about once a week (~300-350 miles). I have a little over 11K miles on the bike now and noticed a missing o-ring during my last cleaning. I use Motorex degreaser and Road Chain Lube, as well as a chain brush and terry cloth towel. I check the tension after cleaning and lubing and have adjusted the chain only twice.

Am I missing something? What could cause the o-rings to fail?

[DarkMonster620]

Pic?

[stopintime]

I'm surprised they last as long as they do.

Sometimes, with a low sun from the side, I see the shadow of the chain movement and it's violent - even at steady throttle - up, down and probably sideways.

I usually replace my chains around 8-9,000 miles and have only seen a small handful of partially broken O/X-rings. 104 links x two rings x ~10 chains = 2080 rings. ~5 partially broken against 2075 survivors. 

I'd say your experience is within "normal".

[Speeddog]

Exposure, FOD, etc.

The grease will escape from that pin in short order.
And then the pin will wear out very quickly.

Plan on replacing the driveline *real* soon.
11k out of the OEM driveline is average.

[Blackout]

I bought a low quality chain (supposedly x-ring) that lost several rings after the first ride. Returned it for refund.