Well I just got the bad news from my doctor last Friday: Stage 4 arthritis (bone-on-bone) requiring total knee replacement on my right knee at age 61. Did a twenty-one mile ride yesterday after a cortisone shot and it felt fine but there was still slight pain at times, not in my knee but up and down my lower leg feeling like a mild electric shock. Not too bad, I can handle that.
More bad news is that I can't seem to ride a conventional bike at all anymore. It appears that my whole lower leg is now bowed from the bad knee and I simply can't bend it enough to pedal and I even have trouble getting my leg over the top tube. Thankfully my father gave me his Trek Pure (an Electra Townie copy) a few years ago that he wasn't riding anymore and I can ride that one. That one is ok for now but I'm looking into getting a suitable recumbent if I want to ride faster and father.