I also tore my acl skiing years ago, back in 1994. Went through a round of PT to get mobility back, but never got around to having surgery. And I was back on the ice figure skating just a couple of months after the accident. I have no problems cycling or hiking or running. Just get a bit achy in the knee if I do a lot of downhill skiing (which I rarely do anyway, I prefer xc) or a long steep downhill climb, but a few hours of rest and I'm good to go again.