🔋 Sensorless
A brushless motor without a position sensor — the ESC estimates rotor position. Simpler and cheaper, but can cough or stutter at very low speed.
What it actually does
A sensorless brushless motor has no position sensor, so the ESC works out where the rotor is by reading the electrical feedback from the motor itself. That makes the whole system simpler, cheaper and one less cable to break — which is why most ready-to-run bashers use it.
In practice
The trade-off appears at very low speed, where there is little feedback to read. Starting from a standstill can feel slightly notchy or hesitant, particularly under load such as a steep climb. Once moving, sensorless power delivery is smooth.
Worth knowing
That low-speed cogging is why sensorless is a poor fit for technical crawling, where precise creeping control matters more than outright speed.