UPDATE: Not actually carbon fiber, just a carbon fiber hydrographic print on a steel YBN chain!
It looks like YBN is in the final stages of releasing a carbon fiber bike chain in 11 and 12 speed. Also available in hollow and non-hollow configurations. Initial feedback sounds fairly positive from testers. It looks like it might be possible to have an almost full carbon fiber bike especially with the recently released carbon ceramic disc rotors!
Who wants to be first to try one out?
