135MPH on I-95 between Brunswick GA and Jacksonville FL on a 1993 Honda CBR1000F with Givi saddlebags and tail trunk. It was about 2:00 AM and I was headed to the races in Daytona. I had been riding at about 85 MPH, my normal cruising speed when I was passed by two Suzuki GSX-Rs going much faster than I was. I let them get about a mile up the road hoping they would attract any cops and then decided to see what the bike would do. I chickened out at 135, but the bike was still quite stable at that speed, even with all the weight in the saddlebags and tail trunk.
The fastest I ever went on a SOHC was on a CB750K0 in the early 1970s riding from Deland to Daytona Beach on Hwy 92, in the early morning hours after dropping off a date. I was riding with a friend who was also on a K0. The speedometer said 130, but I'm sure it wasn't that fast. The tach was around 8,000 RPM, but the needle was wavering around, so I'm not sure of the RPMs. The gearing was whatever Honda changes it to after the recall for the broken chain problem.
Related to this. One year at Daytona, I put the K0 on a dyno when the American Motorcycle Institute was offering free dyno runs. The guys there said my stock K0 (except for baffles out) was putting out as much horsepower at the Kawaski Z1s. Ah, the good old days...