Does anyone know a fix for the annoying vibration at around 5 to 6k RPMs? My hands go numb after riding for a short while. Maybe different handlebars? I just did my 600 mile oil change. Own it for about a month. Love the bike, but this vibration is very annoying to me. It happens to be the RPM for most of my riding at cruise speeds. Should I just downshift and rev the piss out of it? Haven't seen past 8K yet. Don't see the need and I'm not experienced enough yet. thanks for any helpful info. 