I don't know how far off the speedo is but today I was about 1/2 way up a 1/2 mi. hill doin 60mph when it struck me why not and before I got to the top of the hill I backed off speedo showing 120 mph and the ST showed no signs she was at her limit. I know these are probably no where near the fastest or quickest bikes around but my only other street bike was the PC 800 and to me this ST is sumthin else probably trouble for me