To smoke weed. Riding being the act of getting high or smoking, and Bikes being the weed. Regular adjectives are used do describe the quality of the bikes. Originated in Conifer, Colorado.
Dude, Zach, Lets go Ride Bikes after class.
-Can we ride at your house?
Yeh sure But I dont have very many bikes, or any good bikes.
-Ok ill bring my bikes.