Rubiks Cubes have been around since the early 80’s, and Unicycles have been around since, well, the invention of the wheel as far as I can tell. And in that time every possible new idea around either one has been done. Until now that is!
Although there are a lot of people that can ride a unicycle, relatively few can ride an inverticycle (Probably around 20-30 people in the UK). Solving the standard 3x3x3 Rubiks Cube isn’t that rare. However, if you drew a Venn Diagram of people that could do both, it would be a very very slim slither of overlap. If you add to it the people that have done both, and have video evidence for it, I believe that will give you an intersection with one person in it. Me!
I will be getting in touch with Guinness shortly to see if there is any kind of category for this record