You weren't running at a caloric deficit if you didn't lose weight. You are probably underestimating your caloric intake (very common), and probably overestimating caloric expenditure; biking doesn't actually burn that many calories per unit of distance. If you actually ran a 1500 calorie deficit for 2 months, or any significant deficit for that matter, you would have lost a very noticeable amount of weight. There are 3500 calories in a pound of fat, so at your claimed rate you would have lost ~25-35lbs in that 2 month span. Weight loss (and weight gain) is not complicated and does not require keeping track of a lot of factors. Take in fewer calories than you burn, you lose weight. Take in more, you gain weight. Roughly equal intake and outtake, you stay the same. That's really is all there is to it.