ok so as a gym rat, really there are three steps to get six pack abs and they are in order of importance
1. change the way you see food, eat less, eat more often, eat healthier, if it calories from fat are greater than 10-15% of the total calories you should avoid it
2. cardio, and not this bullshit light jog for ten min crap, im talking 30 min a day 5 times a week work out a good sweat kind of cardio
3. ab exercise, at this point in the process the exercise is really just to get the abs to pop, its the first two that are all that maters,
as far as riding, too often people who ride arnt really getting the cardio they need, ie they go too easy, distance doesnt matter intensity does, try biking hills for thirty minutes