In this article, we aim to shed light on what the PAS (Pedal Assist System) is, why Delfast decided to integrate it into our electric bikes, and whether it's truly necessary for the modern e-bike experience.

Electric bikes represent a unique hybrid between human-powered bicycles and motorized scooters. Without the PAS system, an e-bike could function purely on pedal power like a traditional bike, or entirely rely on the electric motor, much like a scooter. Historically, the motor-assisted pedal was introduced as a fallback option when engines failed or proved insufficient—such as during steep climbs. Over time, advancements in motor technology eliminated the need for pedals on powerful e-bikes, shifting the focus towards lightweight, motor-driven solutions.

However, this evolution didn’t eliminate the value of pedals altogether. With the advent of sophisticated electronic controls that manage both the rotational speed and torque of electric motors, the PAS system now offers riders a seamless blend of human and machine power. This setup ensures smoother pedaling, extends battery life, and maximizes overall efficiency. As a result, e-bikes today stand as the most practical and energy-efficient personal transportation options available, promising a bright future ahead.

Modern e-bikes typically come equipped with multiple motor-speed control modes. While the standard accelerator handle remains popular, some e-bikes are also fitted with the PAS system, which activates the motor-wheel following pedal movements. This system was specifically designed to provide cyclists with additional support while riding. But is it essential to have?

Interestingly, the integration of PAS systems is mandatory across all European countries. This regulation ensures that e-bikes can seamlessly integrate into existing bicycle infrastructure without posing safety risks to other users. Several variations of the PAS system exist, with varying degrees of complexity and cost-effectiveness.

One of the simpler and more affordable designs employs a sensor that detects pedal rotation and interacts with a disk containing permanent magnets. Although this setup is easy to implement, it has a notable limitation: it lacks precise control over the motor's speed. Once the sensor detects pedal movement, the motor typically kicks in at full power, which can be disconcerting, especially when entering turns. Additionally, the motor may stop functioning temporarily if there’s a pause in pedaling. Consequently, many e-bikes equipped with this system also include an accelerator handle. These setups are commonly found on heavier e-bikes where the primary mode of propulsion is throttle-based, making the imprecise response less of an issue.

On the other hand, for riders who prefer to rely on pedal assistance rather than throttle, more advanced PAS systems are available. These models incorporate a torque sensor that measures the actual force applied during pedaling. This data is sent to the controller, enabling a more accurate coordination between the rider's pedaling cadence and the motor's output. Such systems allow riders to customize how much effort they want the motor to compensate for—say, 50%—and adjust accordingly. Popular brands offering these high-end PAS systems include Bosch, Shimano STEP, and BionX. These units often resemble conventional bicycle frames and can be retrofitted with minimal modifications.

These advanced PAS systems are particularly common in mountain e-bikes, which typically operate at speeds below 25-30 km/h. Their primary role here is subtle, unobtrusive support for the rider. Delving deeper into this topic reveals a growing variety of PAS configurations, underscoring the importance of harmonizing human and electric power in e-bikes. Manufacturers continue to explore optimal levels of motor assistance, whether partial or full, temporary or continuous, and the maximum allowable power before classifying an e-bike as a motorcycle.

Ultimately, the answers to these questions shape the distinct characteristics, designs, and legal status of e-bikes on public roads. So, to summarize, what exactly is PAS and why did Delfast opt for it? The PAS system helps prolong battery life by reducing peak loads, and given that batteries remain one of the costliest components of e-bikes, this benefit alone justifies its inclusion.