FSE60 is single speed auto clutch. CRF50 has gears and auto clutch so I imagine the top speed would be higher on the CRF. There are 4 other kids that ride with my son with CRF50s. They hardly get out of 2nd gear on any trail or track. FSE60 has no problems keeping up. One thing to consider is the heavier suspension on the CRF50. With tall boy bars bigger kids and adults can ride them. The FSE60 and YCF50 are more scale suspension to kids.