It's winter, so my 4-year old has only pedaled this around the snowy driveway thus far. The 2.1 inch tires are basically fat tires relative to his little body, so he was stoked about riding in snow. He's even more stoked about opening day the bike park. He is an advanced trail rider for his age, yet only has a 15" inseam. He started riding lift-served downhill trails this past summer. At 3 he started building his own jumps in the driveway. Two major problems we've encountered with other bikes: no suspension and rim brakes that heat up and fail. Consequently he developed a fear of not be able to stop and got tired of having teeth rattled out of his head. He would get the dreaded claw hands from too much white knuckling. While other companies ignore the fact that many 3- and 4-year olds can indeed rip, Prevelo gets it. I'd love to write another review after we've done some hot laps in the park.