The 1998 thru 2000 Honda 1100 Shadow Aero vibrate at lower speeds because of the single pin crankshaft. The 1995 Shadow ACE 1100 also has this configuration. There may be others with this configuration in the 1100 V-Twin Hondas, but I am not aware of them. Honda did this to get the Harley single pin crankshaft effect (vibration at lower speeds). It makes a better exhaust tone when adding louder pipes, and also gives the feel of riding a classic motorcycle. I just bought a 1999 Shadow Aero with 5700 original miles, and I will not part with it. They are quickly becoming a prized collector´s bike.