So I have a 2003 Kawasaki ninja 250 that doesn't ride smoothly. It has 8000 miles on it and was salvaged when I got it. A few months ago I had a slight crash on it. It got laid down on the chain side but seemed to not have much damage aside from bent clutch lever and pedal plus some road rash. About a month ago I noticed it seems to bounce as I ride. It's a rhythmic cycle of 3 quick bounces and a pause that speeds up as the bike speeds up, which makes me think it has to be something that's rotating, does that seem like a correct assumption? I lubed the chain thinking it could be a tight spot, then balanced my tires thinking that could be the problem. The tires definitely needed to be balanced and helped some but it's still noticeably there. Before I balanced the tires it was nearly equally noticeable at any speed but now it's much more noticeable at 45 mph rather than higher speeds. It's somewhat more noticeable at slower speeds than higher speeds. I'm thinking the next things I can try are replacing the chain and/or sprockets. A mechanic told me I need to replace them together is this true? I thought I would replace the chain only and see if that's the problem. I felt it for tight spots but there wasn't anything obvious to me. Does anyone have any other ideas of what it could be or what I might try? I'm also wondering if one or both of my wheels got bent in the crash but I find it odd that I didn't notice the bounce until a month or so after my accident. Granted I had to take some time off due to my torn acl but still.. Is there a cheap, easy way to check for a bent wheel? Any other suggestions? Thanks to the troopers who made it through this whole post and for any help or advice!!!