Took a ride this morning and remembered to check this out. Richmond 5-speed (5th is 1:1), 3.50 rear, 235-60R15 tires. Tach showed about 2600 RPM at 55 MPH. That's about 150 more RPM than the calculator says it should be. The speedometer checks to be fairly accurate with my phone's GPS app. The hardest part was slowing down to 55.