I used the LoseIt iPhone app to drop 20lbs and keep it off. Cycling alone will not make you lose weight, you need to monitor what you eat. The app is basically a calorie counter, in which you enter your start weight, goal weight, desired weight lose per week, the food you eat and the exercise you do.

It's kind of scary how little one can eat to maintain weight. I'm currently 167 and my "goal weight" is always 165. I can have 2,100 calories a day. That goes quickly. I've never cut things out of my diet, but I do limit them. If I want to eat cookies, I'll only eat two or three. That satisfies the urge, but is still "ok" for losing weight.