Hitech,
I am 10 and 11 months out and I often sit on the recliner and let the knees rattle away like a metronome...I'm stopping that BTW, it might damage them. Road-biking, I am up to 15 pretty hilly miles at average of 17 mph clipped in and totally enjoying it, they make a fair amount of noise biking too. Hurt a bit after the ride that 1st night, but man, I can hike, do stairs, walk miles at a real good clip....it's amazing.