Bicycle riding is the good exercise. If you want to buy a bicycle for your kids, you can purchase them from the stores from www.amazon.com. Some children riding the bicycles for fun with friends as the videos. Some parents like it as they think that will make their children be brave in the future but some do not like it as they think there might be the serious accident. If you do not like it you should forbid your kids in advance.
The following free streaming videos are from www.youtube.com