A balance bike is a great way to teach kids balance and start them on their way to riding a “real” bike. While benefits can include learning how to steer without having to pedal at the same time, the bikes themselves can cost upwards of $150. For the price of materials (less if you use recycled parts) and a little bit of design work (the software is free), you can design and build a custom balance bike.
Before you start, download and install Autodesk 123D Design (it’s totally free). 123D Design makes it easy to manipulate all kinds of shapes and create viable designs using numerous materials. For a general tour of the interface and commands, see these short tutorials: