slink - cycling is one of the BEST ways to recuperate your leg strength after ACL surg. In fact, your PT will demand it early and often! It will probably hurt a bit at first... I would highly recommend you jump on that stationary bike when comfortable to do so because your quad will atrophy a lot in just a short time.

The surgery is daunting but it really is much better than most make it out to be. I tore mine via TKD originally too (and re-injured stupidly a few years later, but #2 one's held up awesome and I am in better overall fitness now than I was while doing TKD). Don't hesitate to ask questions of your care professionals and find out what they think. And feel free to PM me or ask others here, think several of us have had the surgery.

Good luck with everything, and welcome to the re-engineered