That is mentioned in the article: > All of that is working, too, with independent tests showing properly race-prepped drivetrains to be as much as 98% efficien

That is mentioned in the article: > All of that is working, too, with independent tests showing properly race-prepped drivetrains to be as much as 98% efficient. > That elusive 2% > As good as chain optimization has become, there comes a point where there’s no more optimizing left to do, and there are no other options but to rethink the system. Though, not as in any modern drivetrain but high-end competition drivetrains. At least I imagine it would be with really expensive solutions like Ceramic Speed bearings everywhere.