I’m running the 15t pinion with this motor on 6s and it’s been great. I run 1400/1600/1800 headspeed and it’s got plenty of power for big air flying and 3D. Motor comes down lukewarm and my flight times have improved. I get around 8 minutes at 1400 HS, 6 min at 1600 HS and about 4 min at 1800 HS. Using a 5200mah 6s.