I know this sounds nutty, but my girlfriend bought me a old Schwinn Woodlands Mtb from Salvation Army and now after I finish painting it, it will be a fantastic heavy duty single speed. By the way when I started the project it was quite a daunting chanllenge, the forks are wrong, the handlebars, were wrong, the stem was wrong, and so were the wheels. But i sold all the parts or traded them and I was able to successfully fund my project.