If someone is DTR, it means that they are excited to do basically anything. This is especially true of situations of craziness, ridiculousness, randomness, and spontaneity.
DTR can be a lifestyle. It can also be a mood.
me - "Hey, we're not doing anything... Wanna go light some stuff on fire?"
friend - "Sure, man! I'm down to ride!"
me - "Later we can go climb some buildings and point laser pointers at drunk people!"
friend - "Totally DTR."
If someone is "Down to Ride" he have always lust to go with his Bicycle, no matter if the temperataur is below zero, bad weather or if it`s night. "There`s no bad weather. Only bad cloth...." is something he could say, or "Eh man, whats up? Don`t be lazy, get up and go biking!!"
Man, he is definitely down to ride...
I´m down to ride