I broke my PC 991 PowerLink on my morning ride. The chain had 2,500 miles on it and was removed only once for cleaning at approximately 1,500 miles. The existing PowerLink was reused. I always lube my chain with ProLink after every other ride and clean the chain with the Park chain cleaner.
I have not seen this situation discussed on the forums—I don’t know if it is normal or some kind of aberration.
I had to get a ride back home because I did not have a spare PowerLink or chain tool.
In the future I am riding with 2 spare PowerLinks.