Participatory design methods face challenges when designing for a widespread youth community. In such projects, it is not enough to design in collaboration with a few selected individuals; one must also strive to understand the community at a deeper level and incorporate its values and practices into the design solution. We report on our process of designing with, and for, an identified youth group: the Parkour and Freerunning community. We show how the successful design relied not only on employing methods of participatory observation and participatory design, but also on acquiring an understanding of the practice as a "fun community", valuing play over achievement and competition.