Decathlon Btwin 100 Frosty Blue Hybrid Bike 16" Kids 3'7" to 4'0" | 4-to-6-year-old kids who are beginning to learn to ride a bike. A simple 16" bike for kids aged 4 to 6, with a simple chain guard, reflectors, and a bell. The bike comes with easy-to-grip handlebars, a comfortable saddle, and pedals that are appropriately sized for small feet. These features are designed to make the learning process enjoyable and frustration-free.