Years ago we had a tolerance on our (Ford) speedometers of -1/+5 mph at an indicated 60 mph. The reason for the skewed tolerance had nothing to do with warranty, it had everything to do with speeding tickets. It was better from our perspective to have the speedo read high than it was to read low and cause us to be blamed for people speeding. If I remember correctly, there was also some obscure govt reg involved as well. btw, we also had an unpublished automatic 500 mile extension on the warranty to cover any odometer inaccuracy, so for instance a 12,000 mile warranty became a 12,500 mile warranty in reality.
These days with modern electronics and manufacturing processes, it's normal to see tolerances of -0/+2 at an indicated 60 mph on automotive speedometers. I've got no idea what kind of tolerances H-D has, but considering what they use for the really important stuff like cranks,

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Jerry