Typically when kids outgrow Bmx bikes and want to rided around etc... and not just dirt riding. They will move to a mountain bike. Like the Trek you posted. How old is he and how tall? My boy is 12 and I gave him my MTB and he loves it. Regular 26" Rims. Adult size but he just lowers the seat height. He stills rides his bmx but for just playing around a bit. Big difference being on a mtb.