Another forum that may helpful with dieting tips as well http://forums.menshealth.com/eve/, I'd particularily refer to success stories for tips on what works. Although there is also a cycling forum.

Although I think your calorie intake is high for someone that is trying to lose weight. There is also another aspect that I haven't seen mentioned.

If you weren't excercising before, you probably don't have alot of muscle mass. Muscle weighs more than fat, so you could initially be losing body fat, but not weight. In the long run, the added muscle will be beneficial to your weight loss. Due to the fact that muscle burns more energy than fat, even at rest, there is a 3:1 calorie/per hour burn ratio when comaring muscle to fat. The more muscle mass, the more calories needed to sustain your energy level and if the calories aren't being provided by your diet, than your body will burn stored fat for the needed calories.

I encourage anyone that is cycling to lose weight to also compliment that with some core excercises. The added stregnth in the core will benefit your riding and the added muscle to area other than your legs will further benefit your metabolic level allowing you to burn more calories.

Where did your protein come from? Losing weight doesn't always mean losing fat, if your protein level was insufficient, you lost muscle mass as well, since your body would leach the protein stored in your muscles to compensate for the lack of protein in your diet.

There isn't a credible nutritionist in the world that would tell you losing that much weight that fast is healthy.