Using the Merida Matts J20 Lite is easy. Just hop on and start pedaling! The single - speed gearing means you don't have to worry about shifting. When you want to stop, use the front v - brake by gently squeezing the child - friendly lever or the rear coaster brake by pedaling backward. For kids around 7 - 9 years old and 111 - 130cm tall, this bike is a perfect fit. As for maintenance, keep the bike clean. After riding in the rain or on a muddy path, wash it with a gentle stream of water and dry it thoroughly. Check the brakes regularly to make sure they're working well. If you notice any loose parts, tighten them or take the bike to a professional. Also, store the bike in a dry place to prevent rust. With proper care, this bike will serve your child for a long time.