I'm having a chain issue and not exactly sure where to go from here. If i bounce on the rear the upper section of chain will slacken and hit the chain stay.. Anytime i ratchet the pedals while pumping the suspension the same thing happens which causes the chain to drop off the chain ring eventually. I can weight the rear while stationary and back pedal and the chain basically just slackens without moving. Everything seems to be spinning freely and suspension is tight. Just installed brand new chain and cassette hoping it would solve the issue and it has not. I'm leaning toward maybe the wheel bearings binding slightly, any suggestions aside from buying a new bike which will definitely solve my issue?