I have spinal stenosis at the lower neck. I could get maybe 10 minutes of riding in on my upright when the arms starting going numb, forcing me to stop for awhile and give my arms time to recover. Also the pain in the neck was forcing me to constantly look down instead of out in front of me. Nearly nailed a kid in a stroller on a bike/walking path when I didn't see it in front of me until the last second. All that's in the past the minute I got my Sun EZ-Sport a few years ago! Now kicking myself for waiting so long to make the switch.