Hola Raquel. Please forgive me for replying in English, although I can read and understand Spanish, which I learned at home and not at school, I hope we can still communicate.  First, please tell me where are you located. When you wrote Nuevo Leon, it looks to me like it could be in Spain. I live in Heidelberg, Germany and I am a bicyle mechanic and sell used bikes to the university students at a very low price because I am not interested in making a lot of money as this is a hobby for me. I also belong to an organization that sends bicycles and wheel chairs to Africa. I used to have a bicycle shop that I named 'Pedalero', but I closed it because I was traveling too much and could not do it on a regular basis. If you are ever around Germany, please come by and visit me. Hope to hear from you again. Gilberto Rodriguez - Pedalero