well guys here is the real skinny about knee replacement I just fininished knee surgery I had it 5 weeks ago have finished physical theray and back on my mountain bike now guys I was the one in a million guyson e ther other extreme it will hurt for weeks sleeping is the worse especially if you are a side sleeper can not put pressure on the side of the knee lots and lots of swelling and you may have to sleep in a chair for weeks riding a bike maybe 3 to 4 months so there is alot of different things can happen I was in super athletic shape a hiker and biker so if you are not in good good physical shape your recovery will be longer so we are all different not a negative person my advice be prepared for the worst and if it falls short that would be great do not listen to others you are different from them good luck I hope this helped you prepare