What are the most effective techniques for maximizing speed and maintaining momentum on electric mountain bikes when cycling on flat terrain, considering factors such as tire pressure, cadence, gearing, and body positioning? Are there specific strategies for optimizing the motors assist mode to achieve the highest speeds, or is it more about fine-tuning the bikes mechanical components? Additionally, how do the different types of electric mountain bike motors, such as hub drive, mid drive, and rear drive, impact the riders ability to maintain speed and momentum on flat terrain? Can riders with more experience cycling on flat terrain share their tips and tricks for getting the most out of their eMTBs in these conditions?