We have followed the advice of expert tuners, including extrapolating formulas used by A. Bell and G. Jennings. Selecting quality materials is the first step in making our designs come to life. RMH Performance Tuning is an American company based in Georgia. Our fabricators are located in Delaware, Georgia and Indonesia. While the best approach to building an exhaust should take into consideration specific engine characteristics like, port timing, displacement, and compression ratio, the designs we've chosen provide good performance across the range of stock to highly modified motorized bicycle engines.