https://www.openstreetmap.org/way/242819311/history

mtb:scale=-1
on way/242819311/history

maybe mtb:scale=1- was intended? Or mtb:scale=0 (extremely easy, so easy it got negative)

or maybe bikes are anyway banned there?

ancient edit so author does not remember (as expected, maybe I should have not bothered them) https://www.openstreetmap.org/changeset/27730995