Pedal Assist – what is it and how does it work?

Pedal Assist is common to e-bikes
Pedal Assist is an operating mode on e-bikes designed to turn on the e-bike motor to help you pedal. Most e-bikes have a pedal-assist feature built in that lets you activate the motor by pedaling instead of using a twist or thumb throttle.  The advantage is simple.  Instead of twisting or pressing a throttle to activate your e-bike motor, just start pedaling and the motor will power up automatically.

To operate, Pedal Assist electric bike needs to sense that you’re pedaling, by using one of (or a combination of) two kinds of sensors – a speed sensor or a torque sensor.  The e-bike manufacturer installs the speed sensor, like the torque sensor, in the bottom bracket of the bike – the axle or shaft that connects the two pedals and allows them to rotate; the sensor can also be found inside the motor for “mid-drive” e-bikes. The speed sensor detects some forward pedal rotation or a certain rotational speed and activates the motor to power your ride. A setting on the e-bike display determines how much power the motor uses to assist your pedaling. The torque sensor detects the force of your pedaling before activating the motor.  Again, a setting on the e-bike display determines how much power the motor will use to assist you. A lot of pedal force, like when you’re pedaling up a hill, will produce more motor power than a little force like when you’re pedaling downhill.

Speed Sensors versus Torque Sensors
Simplicity and predictability are the advantages of speed sensor Pedal Assist.  You know that as soon as you start pedaling, the motor will power up, and you can set how much motor power you want to assist you while pedaling.  The amount of motor power is easy to control through the display.  With speed sensor Pedal Assist, the motor can overpower your pedaling.  In this case, you pedal, but you feel that you’re not adding any power to the ride – the motor is doing all the work.  If you want to contribute leg power and get exercise, you must downshift or lower the power level on your display control.

Torque sensors guarantee you’ll have physical exercise on your e-bike.  The torque sensor only activates the motor as long as you’re putting pressure on the pedals.  So, you have to gauge the level of power assist on how much exercise you want to get from pedaling.  Unless you have a throttle to override the torque sensor, there’s no free ride where the motor does all the work for you.

Luxmea Electric bike products come with both a speed sensor Pedal Assist and a thumb throttle override by default. Riding off-road can be challenging – sudden steep rises, rock crawling, transitions from hard surfaces to soft surface — all require attention to control.  The throttle and speed sensor make it easy to adjust motor power on the fly so you can keep you mind focused on the obstacles ahead.