I know from experience that 9-to-11-year old children can handle 30-km bike rides, subject to a few constraints:
- Regular hydration and nutrition are critical—even more so than for adults.
- It is crucial to practice 10 km and 20 km bike rides many times before tackling 30 km rides.
- Kids dislike riding for the sake of riding. There must be some objective, such as a playground or a pizza lunch at a destination point 15-km away.
- Are 30-km rides useful for the development of preteens and teens? If not, are they downright somehow harmful?
- Will the benefits be seen in other activities, such as increased stamina in tennis and football?
- Are longer rides of 60-80 km—tackled in small increments—within the ability of preteens and teens?