This mike has a sturdy frame. It was easy to assemble. My son is slightly too short, even with the seat adjusted up. This will last a long time for my now 5-year-old. His birthday is today, and he loves it. Back story on why I decided on this bike. My son has some learning curves and could not figure out a regular bike with training wheels. So I got him a trike it makes it a little easier for him. I didn't think I would find a trike big enough for 5+ but I did and it's a awesome bike.