Let's delve deeper into this topic. The use of traditional bicycle frames for long-range electric bikes with high-speed capabilities has proven to be a challenging task. It’s akin to integrating a gasoline engine into a horse-drawn cart; while Carl Benz managed to accomplish this, the design had to be robust, as evidenced by Bertha Benz's historic journey with her children. Here's what it looked like back then:

Clearly, it doesn't resemble a modern car. Initially, inventors and engineers tend to adapt existing designs. Carl Benz used a cart, while contemporary engineers adapted regular bicycles. However, it quickly became apparent that using traditional bike frames for electric bikes often led to frame failure. The reason lies in the different distribution of mechanical loads. Electric bikes require rechargeable batteries, which need to be housed somewhere on the frame, and they typically have a high-capacity power source for the electric motor. Additionally:

- Unlike a conventional bike, which relies solely on human muscle power, an electric bike is driven by a powerful electric motor with significant torque transmitted to the wheel. This increases the load on the rubber, rim, and spokes. Furthermore, no standard bike frame is designed to handle the twisting forces generated by a high-torque electric motor, particularly in aluminum frames with forks. Engineers have been working tirelessly to adapt these frames, but despite numerous improvements, frames still break down. Similar issues arise with bolt fasteners and welded joints. Hence, we now see unique frame designs specifically created for electric bikes. After exploring all possible options, we developed our own frame design.

Now, let's talk about the battery. A high-capacity rechargeable battery pack consists of multiple interconnected cells, forming a bulky and heavy structure. Its size is directly proportional to its capacity, and reducing the size compromises the bike's range, which is arguably its most critical feature. Thus, the larger the battery, the better. For instance, who would want an e-bike with a range of only 20 kilometers? Here's a picture of the actual battery we use in our electric bikes:

To ensure safe operation, a lithium-ion battery pack requires reliable mechanical protection, which is nearly impossible to achieve with a traditional bicycle frame. There are two main challenges:

First, there’s simply no space to accommodate a large battery in a conventional frame. Secondly, a small battery cannot provide the necessary range, which might suffice for urban cyclists but not for those looking for longer distances.

Typically, such e-bikes look something like this:

In the image, we see a small battery in the location where a water bottle would normally go and a motor controller in a black plastic box. It almost feels like looking at Benz’s first car, doesn’t it?

However, for a large and powerful battery, this design isn’t feasible:

Firstly, it barely fits (you can refer to the earlier image). Secondly, the battery must be protected from mechanical damage. The battery compartment, the box containing the battery, should maintain optimal operating temperatures. Lithium-ion batteries can heat up significantly, sometimes reaching melting points, so we aim to prevent such overheating. Additionally, considering the substantial weight of the battery, it’s crucial to position it in a way that keeps the center of gravity low on the bike. A lower center of gravity enhances stability and maneuverability. This is why Delfast developed a specialized frame where the battery compartment is designed as a box-like spatial frame that houses and protects the battery and control electronics. Essentially, it mirrors the design of a personal computer’s system unit. Here's what it looks like:

This frame serves dual purposes: protecting the battery and providing a secure location for it. It’s engineered to lower the center of gravity, making the e-bike more durable and agile. The frame’s dimensions depend on the battery and control electronics’ capacity, maintaining a consistent shape and size. This approach aligns more closely with motorcycle design, where the frame is built around the engine, rather than the conventional bicycle design. Choosing the right height is straightforward. By varying the wheel size or adjusting the saddle height, the frame can be customized to fit cyclists ranging from 166 to 180 cm and beyond. All you need to do is consult a sales manager when purchasing your e-bike.