I'm not sure what all of you are talking about. If you change your calorie intake and or output by 3500 calories a week, you should lose 1 lb a week. That assumes your weight was stable before. That is 500 calories a day. Riding 10 miles at a 15 mph pace should burn about 500 calories, depending on your weight.
As long as you are not cutting down on other activites or eating more, the weight should start coming off soon.
50 miles a day is overboard unless you are trying to become a professional or training for some specific event. Studies have indicated that 1 hour of vigorous exercise a day is ideal for cardiovascular health.