Seeing a few posts on tires. My bike has the original 25 year old tires. I notice when I push the bike around the back tire/ suspension bounces slightly. I also notice when I slow down rapidly from 60km/h my suspension bounces a bit. I'm assuming it's my old tires that have sat for many years. My father thinks the rear axle is slightly bent but it seems to spin true. They aren't cracked bad I've only rode about 2 hours on it, will they ballence themselves out? Should I replace?