There is a steam powered motorcycle in the Musee Mechanique at Fisherman’s Wharf in San Francisco. You can see it for free. It was built by an individual who intended to go into production. He claimed to have reached 100mph which, if true, would have been a steam-powered speed record.
Unlike other steam motorcycles he solved the problem of how to monitor the water level by placing a sightglass down on the right side… a lot of steam bikes have all the gizmos up in front of you and look really awkward. I think at the end of the day the power-to-weight ratio of an external combustion engine is too low for a two-wheeled vehicle and that’s why they never really manifested themselves.