under or over geared?

[suicideneil]

"99% accurate", sometimes it doesnt hold true though, so its just a case of stocking up on spurs & pinions until you find a ratio that gives you the speed/torque you want & runs cool too. As for finding the right gear ratio, I wish there was, but even BrianG's mighty calculator can only provide the ratio needed for a certain speed on a certain voltage etc etc, it cant tell you if the motor/esc/batteries will run hot or not- just too many other variables (weight being the largest).

[lutach]

Here is my situation. I'm doing a comparison of a few ESC. My current motor is an Aveox 1412/1y. The spur gear is 51T and I ran my truck for 8 minutes with the MGM 16016-3s and the MM. The ESCs were cool and warm and the batteries (7.4V 5000mAh wired in series) were cool. The Aveox was pretty hot after the 8 minutes. I have now put a 17T pinion to see what will happen. If it gets hot, I'll try a 15T. If the 15T gets hot I'll go with a 14T. I have noticed guys in the forum running spur gears in the 40s and pinions ranging from 12T (I'm not 100% sure) to 16T pinion and they have good temps. So I'll see which one works better and drop a line here. Other people should also add their information on this as well.