MAHLE Smartbike Systems X20 TCS Bottom Bracket - PF46-30 With Torque/Cadence SensorMAHLE Smartbike Systems X20 TCS Bottom Bracket PF46 30 With Torque Cadence Sensor. MAHLE TCS (torque and cadence sensor) bottom bracket helps riders conserve battery by measuring the power input from the rider and adjusting the support from the motor accordingly. Torque accuracy of approx. 95% (+ 5% of tolerance) Torque signal refreshing each 5ms Cadence signal of 40 pulses per revolution