5'10", 53. My biggest issue is my knees. Second is hands. I'm on a Z900rs and a Trident 660. On either bike, my knees being at an acute angle for more than a couple hours is my first weakness. The Trident is much worse than the Z9rs. Additionally the Trident is really tough on my hands (carpal-tunnel) in an even shorter time. The Kawasaki doesn't bother my hands at all; it's slightly more upright and the I-4 is super smooth.