|Source: Wet Leather Biker-|
Rocker leather jeans? They look more like cowboy leather jeans that cowboys and other westerners wear, including cowgirls when they're are their horses, ranches, and involved in other western activities.
With the chain wallet that the man is wearing in the photo and video, those are very common with biker men and to some extent biker women. Who wear chain wallets both with their leather and denim jeans and they're out on their bikes. For obvious reasons and style is one of them, but to protect their wallets when they're on the road, as well as around other bikers and people involved in biker culture.
Leather jeans of course are very common in rock and roll culture. People in that community can thank Jim Morrison from The Doors for that. But leather jeans, leather jackets, leather boots, and other leather clothing, have been a big part of rock culture at least since the early 1980s with the heavy metal wave, if not the late 1970s. Jim Morrison from the late 1960s was really the first famous rocker to wear a leather suit that included black leather jeans, black leather jacket and black cowboy boots.