How do PAS Levels work? Cadence and Torque Sensors?
PAS Stands for Pedal Assist System
The PAS levels correspond to how much help the motor will give you while pedaling.
We will look at a bike with 5 PAS levels, the most common amount on Biktrix bikes. However this explanation still fits if your bike has more levels or fewer.
If you are at PAS level 1 of 5 you are using ⅕ of the motors available help. Level 2 you are using ⅖ of the available help, level 3 using ⅗ of it, level 4 is ⅘ and at level 5 you are using all of the motors available power and assistance to help you.
The main benefits of PAS is that you can get power from the motor without having to use a throttle - just pedaling will be enough.
Pedal assist systems are classified into two categories based on different sensors used: Cadence and Torque sensors. Biktrix bikes use each of these and some models use both.
Measures IF you are pedaling or not pedaling.
Sends the controller a signal of on or off (1 or 0) but nothing in between.
Turns the motor on when you pedal and off when you are not pedaling.
Must control boost level and speed by adjusting PAS level not by strength of pedaling.
If you pedal faster than the motor is spinning the motor will work against your efforts.
Measures the force you apply when pedaling and uses that force to determine how much electric power the motor assists with.
Sends the controller a number BETWEEN 0 and 1 corresponding to how much force you are pedaling with.
Amplifies your pedal input - when you pedal harder the motor will work harder while if you pedal lighter the motor will produce less power.
You adjust the assist level through a combination of how hard you pedal and the PAS setting you are using on the bike.
How do the Biktrix DUO bikes work with two batteries?
The Duo bikes are equipped with a dualizer. This dualizer switches from battery 1 to battery 2 constantly, depending on the battery's charge. So actually, the bike is only drawing from only one battery at a time, but the dualizer switches from battery 1 to battery 2 and back.
As only one battery is really connected to the bike and display at a time, the display will only show the charge of the battery the dualizer is currently drawing from. Therefore, the changes between the batteries will probably not be noticed by the rider.
The dualizer switches between the batteries based on the charge. If the charge of battery 1 is lower than battery 2, the dualizer switches to battery 2. The bike is now drawing from battery 2. If the charge of battery 2 is lower than battery 1, the dualizer switches again. And so on...
So you might wonder how does the Dualizer works with two batteries of different voltages ie a 48V Hidden battery and a 52V Range extender. It essentially acts as a switch that allows for a full circuit between one of the batteries and the motor while isolating the other battery from the circuit. Thus you aren't running these two batteries of different voltages simultaneously through the bike but instead, it is a switching system to ensure each battery is isolated from each other but still able to power the bike.