Some bikes are engineered for thrill-seeking twenty-somethings — not for riders managing joint pain and rising insurance costs. From the supercharged Kawasaki Z H2 that punishes your spine with 200 horsepower, to the deceptively stylish CB 650R that forces your aging body into a contorted crouch, these eight Japanese naked bikes are mechanical masterpieces your over-45 frame might deeply regret. Let’s watch the video and see which models you should steer clear of…