Of all the different blind bags in the new Series 19 LEGO CMF, the Mountain Biker Minifigure is the easiest to find. It’ is so easy to feel for the large blue bike frame. But also inside the bag are 2 black tires, and a minifigure in a second plastic bag.
I might be wrong, but I also think this is the first time a mountain bike has been produced in LEGO.
The Mountain Biker Minifigure from the LEGO CMF Series 19 appears in these sets:
71025 The LEGO Series 19 CMF (Complete Series of 16 Complete Minifigure Sets) (Release date 2019)