The most competitive event in tandem road racing (?), is in the quadrennial Paralympics, that follows the Summer Olympics in the same location. The road race is to take place on September 8th.
The B designation indicates tandem with a visually impaired stoker and sighted pilot. There are B men's and women's teams, but no mixed teams.
Of course, the visual impairment doesn't affect wattage, and so it will be interesting to see what these teams can do. Also, to see how with high-level racing what bikes are used, and how they are equipped.