After taking a long bike ride yesterday, i had dull achy chest pain and back pain and its not going away. what are possible causes?

Muscles: If the pain has been constant then more than likely you are having muscle aches. Poor positioning on the bike can cause this, this is amplified by long rides. Also not being in shape enough to complete the long ride without feeling beat could also be a part. If the pain has been coming and going away completely, and gets worse with activity then see a doctor today.