What are the key performance indicators that define an eBikes power output and speed, and how do various models on the market compare in terms of these metrics? Specifically, how do factors such as motor type, battery capacity, and gearing affect an eBikes acceleration, top speed, and overall efficiency? Are there any industry standards or benchmarks that manufacturers use to measure and report these performance characteristics, and if so, how do they account for variations in rider weight, terrain, and other external factors that can impact an eBikes performance? Additionally, are there any notable differences in power output and speed between eBikes designed for different applications, such as commuting, mountain biking, or touring? How do these differences impact the overall riding experience, and what trade-offs do riders need to consider when choosing an eBike that meets their specific needs and preferences?