I work as a postman and being as fast as humanly(more like physically) possible is not just a plus but a necessity. I am completely clueless and would like to know how I can go as fast as possible within reasonable limits, since I can't afford expensive things. So I'm asking about what things I can upgrade in my bike and also about proper form that can maximize the speed as well. If it can help, my bike's brand is called SCOTT and its a red small bike, that I got for 50eur. The bike can go fast but am sure as hell that it can go FASTER.