Oh, yes, I still bike---I get in about 120 -160 miles a week in during the summer and fall months. Since I had my BTKR in November, the only cycling I did was on a stationary bike. To be honest, it took me about three to four weeks to get a full rotation while sitting on the saddle---I am not sure as to how long it would have taken me to do it standing up.
I really didn't get on a real bike until about the end of March, as the weather can be pretty nasty for a while here on the Southern Shores of Lake Erie. By the time I got on a real bike, I was pretty close to be completely healed.
I would imagine that your quads are still very tight and the muscle may be a bit weak, so it may take some time to loosen up the quads---as well as to strengthen both the quads and the hammies. That may take some time, as stamina and strength are normally the last to be attained completely. How tight are your quads and hamstrings?
Even when I got on the bike being close to about 89%---it took me some time to build up my stamina and build up the miles. Now, centuries are not a problem.