We've taken Ying Ying biking a couple of times now. She rides in a trailer attached to her dad's bike. The first time we went out, we used a helmet that had been passed down to us. It didn't work very well because it has a pointy, aerodynamic back which caused it to come down over her eyes anytime she rested her head on the seatback. This is her new helmet - smooth all the way around. It worked great!