I love skiing! But I’ve never tried a ski bike. The video above features extreme ski biking; this guy is really good! However you don’t have to use ski bikes in this fashion. For those with certain disabilities, ski bikes are an excellent way to make skiing accessible and safe. For those who need helpers for extra safety, the bikes can be controlled by a trailing skier. They can be further adapted to have a sled-like seat accompanied by two skis that can be used like poles for balance and turning.
To me this qualifies as a remarkable use of a bike.