First time on this bike, second time in my experience: this time the chain broke while riding at -10C [that would be 18 Fahrenheit degrees below freezing for the Celcius challenged]. Second time in my experience. This time we had a series of ghost shifts into the granny first and then, just before we crested a hill (maximum power...) wheee! no resistance...., and no propulsion. My theory is that the outboard side of the link broke first, and then it would flex at a certain point in the cycle, causing the ghost shifts.
Happily I carry a chain breaker and quick links. Did wind up late for church.
Whipperman Connex. Just about 2000 miles on this one, no sign of stretching as of last week. That's double our usual mileage with other chains. And it was less than twice the price. Might have lasted longer if we hadn't ridden through the winter.