How much?
I don't know...
But I have decided to weigh myself only once a year now...
I didn't lose any weight after my first full year of cycling - but I dropped two dress sizes.
Depending on the time of year I bike between 300-670km on the road a month and I eat fairly sensibly. I also do some time on a mountain bike and a spin bike...
To date I have completed 13275km on the road since October 2004. I have "lost" only 16kg. I want to lose at least 10 more, preferably 15 at most.
But I have def built muscle in my legs and upper arms... and by mass of course, muscle is denser/heavier.
So I haven't really answered your question, but I guess what I am trying to say is - don't stress about it anymore than just being curious.
You are fitter, feel better and your clothes are looser - you are doing just fine