epa doesn't rate motorcycles, at least not that I'm aware of. In fact, there are very few regulations when it comes to motorcycles at all which is why aptera is making their car a 3 wheeled vehicle, since it is considered a motorcycle.
Yeah, EPA doesn't rate cycles. Only cars and light trucks. I know Harley publishes ratings for their bikes, but with the following disclaimer:
Estimated from fuel economy tests on a sample motorcycle from the corresponding family conducted by Harley-Davidson under ideal laboratory conditions. Not all motorcycle models undergo fuel economy testing. Fuel economy and mileage may vary among motorcycle models within a family. Your mileage may vary depending on your personal riding habits, weather conditions, trip length, vehicle condition and vehicle configuration and other conditions. Break-in mileage may vary.