Congrats on the improving fitness. I would suggest that in addition to your BMI, you also keep track of your bodyfat percentage. A simple $12 caliper will give you a decent approximation. The reason I suggest this is that the BMI, while useful, is not an accurate tool. For example, if in one year you lose 10 pounds of fat but gain 10 pounds of muscle, your BMI stays the same even though your bodyfat percentage has changed significantly with a big improvement in fitness. There are a couple of new BMI calculators out that add additional points of information, usually measurements of waist, thigh, chest or some other combination, in an attempt to circumvent this weakness in the previous BMI tools.
Not trying to rain on your parade. On the contrary, if you have been cycling a lot, you have probably gained some muscle in addition to losing fat and thus your improvements would be even greater than indicated by your BMI.