
Back in 1999, Shimano was granted a US patent for “Multiple Sprocket Assembly for Bicycle,” and in the patent summary they wrote,
The present invention is directed to a bicycle drive mechanism which includes a large number of freewheel sprockets, for example, ten or more and preferably fourteen freewheel sprockets.
Emphasis added. Even the sketches in the patent document show a cassette with 14 sprockets. The largest sprockets seem to float over the spokes, giving the back of the cassette a reverse conical shape seemingly to account for the need for additional clearance. The patent conceives of a special chain to make this possible as well, so it’s not exactly a simple solution.
The patent is set to expire in September of 2019, so could Shimano be working on a drivetrain that jumps 2 gears past SRAM Eagle? Or have they already given up on trying to make this system work?