Castle Creations motor and ESC combo recommendations for the Rlaarlo ROG1:

Micro X2 w/1007-6350kv - 16T pinion / 59T spur on 2s = ~40MPH
Micro X2 w/1010-4400kv* - 19T pinion / 59T spur on 3s = ~50MPH
Copperhead 10 w/1010-5600kv* - 19T pinion / 59T spur on 3s = ~65MPH

*1010 installation may require modifications to fit

Note: All speed estimates are with stock tire diameter, high quality batteries and appropriately sized battery connectors.
Always monitor ESC, motor and battery temperatures on new setups or when changing gearing or batteries.