Charlie, in 2013, I retired and took my "Epic Post-Retirement Ride to Alaska, the Four Corners of the US, Nova Scotia, Newfoundland, and Labrador," 80 days, and 21K miles. Particularly on the San Ysidro, CA, to Key West leg of the Four Corners, I was in areas where if I had ridden at 65mph, I'd have been run over! I found out that the NT could run comfortably at 90mph even in temps that were between 100-105F. As Mike said above, I never used any oil in the time I owned the bike. I traded it in 2020 for a bike that was 16 serial numbers older but only had 22K miles. My 1st NT had 139K on it when I made the trade. The only real problems I had in that 139miles were: 1) I had to have the rear drive rebuilt twice, both times after Honda mechanics changed rear tires and didn't lube the splines; 2) a fuel pump that died at about 128K miles. I think what places the limit on acceptable rpm is most often piston speed. The NT has a short stroke, so piston speeds don't get out of hand until somewhere around 10Krpm.