As a youngster with a pretty good kick I once broke a 1" block chain in a sprint , Owen Mullholland witnessed the event , in fact he pushed me a couple miles with me just sitting with my feet on the pedals , so I wouldn't have to walk home .
I also broke two 3/32" road chains in sprints , but never broke a 1/2" track chain .
No conclusions , just an observation .
Jim McCoin
Fremont Ca