Remember Marv Levy? He was the head coach of the Buffalo Bills during their four Superbowl runs during the 1990's. I recall reading an article about him that laid out his workout routine. At 73 he was running many miles per week despite arthritic knees. He claimed that the running helped address his symptoms, keeping everything at bay. In my personal case, I only have aches and pains when I'm not working out with regularity and with some serious effort. My knees and back hurt when on not putting in hard bikes, runs, swims and weight lifting. Bone-on-bone is a different thing and YMMV depending upon the state of your OA and degeneration. But I find that hard biking is not only impact free - except when you wipe out - but that it really greases up the joints and serves to make me feel great. Give it a shot an see how it feels.