Originally posted by Ex Finn. Interesting, why would one need a chain breaker for a bicycle chain? Usually the sprockets wear out first and that is the time for a new chain replacement also.
Very occasionally, the chain can break, or the chain can get wedged between the frame and the chain rings. Sometimes, that will mangle a link making riding impossible. In cases like that, the chain can be mended on the roadside and you can continue riding and not be stranded an needing a ride in the middle of nowhere. In all the years I've ridden road bikes, that has happened to me twice. But that's twice too many.