There is no clear answer to whether fat tires or narrow tires are better for electric bicycles. The choice depends on personal preferences, riding conditions, and the type of riding you do.

Fat tires have a larger contact area than narrow tires, which means they provide better stability and traction on uneven surfaces. They are also more suitable for off-road riding or riding on unpaved paths. However, fat tires may have a higher rolling resistance, which can reduce efficiency and speed.

Narrow tires, on the other hand, have a smaller contact area but generally provide better performance on smooth surfaces. They are often used for road riding and racing, as they can provide a more aerodynamic shape and reduce rolling resistance, which improves efficiency and speed.

The best advice is to consider your specific riding conditions and needs before choosing between fat and narrow tires. If you mainly ride on smooth surfaces, narrow tires may be the better choice. However, if you ride off-road or on unpaved paths more often, fat tires may provide better stability and traction.