I am wanting some information. I once had a Honda 550 4 cyl. but the speedo was broke. I had a wreck in 84. I can not remember about 270 feet of the wreck. More to the point, I was taching 6500 at the time I saw that I was in trouble. I hit the rear brake a glanced at the tach and dropped it to 5500 rpm before I laid it down. What I NEED to know is how fast was I going? All that I can remember was the sound of the rear tire and then the impact into the rear quater of a 67 convertable mustang. 2 days in ICU, 2 days in recovery and NO broken bones. But I just canĀ“t remember anything after 18 years. I was told that I was squating on the bike as it was laid over holding onto the handel bar. Please email me. I really need to know as to the speed, or at the very least tell me how to determine the tach to road speed ratio.Mike Boots