Use the included Kid & Cargo(TM) Carrier to ride with up to 2 kid passengers. Customize your ride further with additional accessories in our Kid & Cargo(TM) system - turn your bike into an all-weather champion, a grocery workhorse, and more. Designed with you in mind. The differing wheel sizes - a 24" front wheel and 20" back wheel - create a lower center of gravity for increased stability and enhanced efficiency for an altogether smoother ride with cargo in tow. The intelligent torque pedaling sensor system is responsive and matches your pedaling effort. This delivers a more natural riding experience, ensures seamless acceleration, and conserves battery life so you can make the most of all your adventures.