You want to ride your bike indoors? Do you live in a 500 room palace or something? How would you have space to ride your bike indoors. If you are serious about losing weight then biking and cycling is a good option. But you cant do it indoors. Get yourself a good bike and start cycling on the road. This is the most effective way to lose weight. Cycling uphill is also a good option and you will burn many more calories this way. Cycling can even be fun if you get some friends along and go for a long ride.