It is a bit of a paradigm shift when it comes to thinking about e-bike frames. It’s true that high quality carbon fiber bicycle frames are known for being light weight with lateral stiffness and vertically compliance. But, you have to ask yourself if that is important when it comes to an electric bicycle. In my case I wanted all those feature on my non-electric bike, but when it came to purchasing an electric I didn’t need or want to pay for these features.
Here’s why:
- Light Weight: The difference in bicycle frame weight is highly overrated. Since the difference in weight only accounts for about one or two watts of additional power, the reason bike riders lust for the lightest carbon fiber bicycle possible is to lighten the load when climbing hills. Similarly, the number one reason most people give for buying an electric bike is to make hills easier. Although you may need the lightest possible bicycle you can afford or an electric bike to make it up hills easier, you don’t need both. The lightest e-bike with a carbon fiber frame isn’t necessary when it comes to hills because the weight savings just isn’t significant when a rider is being assisted by an electric motor.
- Lateral Stiffness: In theory a stiffer frame is more efficient as less energy is lost to the frame flexing. This is most important when pounding the pedals because it can create energy robbing flex. However, since the rider is being assisted by an electric motor there isn’t a need to pound the pedals. As a result, there isn’t a significant energy loss by the rider due to frame flex.
- Vertical Compliance: When I think of compliance, I think of comfort. But handling is also a part of compliance. I find that tire size and pressure make a more significant contribution to compliance than frame materials. A wider tire with more air volume and lower tire pressure gives me a sure footed and comfortable ride. Therefore, a frame with tire clearance that will accommodate wider tires is much more important than having a carbon fiber frame.
- Durable: All other bicycle frame materials such as steel, aluminum, and titanium are more durable than carbon fiber. A significant scratch in a carbon fiber frame can ruin the frame, whereas a scratch in the other frame materials just adds character and to the story of the frame.
- Precision Engineering: Steel, aluminum and titanium are easier to precision engineer than laying up carbon fiber.
- Recyclable: Carbon fiber is not recyclable while the other bicycle frame materials can and should be recycled.
- Reduced cost: Carbon fiber frames are expensive to make and, as illustrated above, offer no significant advantage over other frame materials when it comes to e-bikes. The savings could be used for better components or just more money in your pocket.
The bottom line? Ask yourself if there are any real advantages to a carbon fiber e-bike. After careful consideration, I think you will agree that a carbon fiber e-bike is not worth the additional expense over other frame materials.
Ken Whittaker