When your rider is ready for a real bike, Trek makes superb, sturdy bikes that will easily last through multiple children. I’m not a particular fan of cartoon characters plastered over bikes, and I love that Trek bikes look and are made like grown-up bikes. The Jet 20 is geared for kids 6 and older depending on height and ability. It features 20″ wheels, the option of either coaster or hand brakes (one of my fav features) and cool extras like a kickstand, fenders, plates, pads. The bike has a lightweight aluminium frame that means I can hoist it up on our bike rack, and a construction that will last through everything from neighborhood rides to off-road adventures AND still be passed down to younger brothers. The Jet 20 comes in blue or green though girls may prefer the color selection of the similarly designed Mystic 20. Like all Trek bikes, the Jet 20 has a lifetime warranty.