ROCHESTER — Noah Ryder was looking for something bigger, with more choices. So, following his freshman year, he left Schaeffer Academy for Rochester Mayo, a school whose population is about 20 times bigger than Schaeffer’s and its enrollment of 78 students in grades 9-12. “Schaeffer just got to be too small,” Ryder said. “And I liked the harder, challenging classes at Mayo.” He’s also liked the tennis at Mayo, which happens to boast one of the t…