I had ACL replaced in Feb after a complete tear along with partial rupture to medial.
They had me up and walking the day after the op but you'll not be able to go anywhere near a bike for at least 8 -10 weeks. Not because it hurts but because the graft won't have healed and you risk tearing it again, it's a much more complex operation second time around. I got an absolute roasting from my physio for doing three easy miles on the towpath after 9 weeks.
Top tips from me – get a good physio, attend regularly and take their advice. Mine worked for Celtic FC and had managed a fair few ACL recoveries so knew what he was talking about.
Exercise it, stretch it but it's important to also follow RICE principles.
Be prepared for slow progress, I hit a real low when I couldn't bend it past 80degrees 7 weeks post op.
It's really important not to put it under too much stress until the graft is properly healed.
Ten months down the line I am back on the bike,doing decent mileages and not having any major issues, it does click and swell. Rest and Ice cures both of these. I also find that if I don't exercise it / ride the bike for two weeks the clicking can get worse as the ligaments loosen up.
On the plus side the surgeon did say that due to be being a keen cyclist prior to the injury my knee was in pretty good shape so the recovery prognosis is good.
Sorry for the really long post but I remember trawling the net before my op and struggling to find decent advice / info. Drop me a line if you need any more, happy to help a fellow ACL sufferer.
oh, one other plus point. The post op pain killers are ace!
G