Most speedo's show overspeed. I like it! When the LEO is on the freeway everyone slows down to what their speedo says. Then I go by using the GPS speed. LOL

 

03 Road King Classic, stock wheels/tires, at 35 Mph according to 'your speed is radar sign' speedo said 38-39, barely rolling bike in garage = 5 mph

I noticed I'd go a certain speed, and not having any other bikes to compare it to, didn't have any idea how fast it should feel compared to car/suv...but I noticed on highway I'd get passed quite handily by people at certain speeds that I was used to passing people in the car/suv. That was first clue, then the garage 5 mph thing, then to confirm it, neighborhood had that speed sign, so I know if was off at that speed.

Thing is, I've always thought that miscalibrated speedos can get worse at speed, so the difference in actual speed could go up a few more mph.

Of course some lady hit me a couple weeks ago, and the bike is totaled, so it doesn't matter now. Had that not happened, I thought about looking into having calibrated, especially for highway speeds when you want to know exactly how fast your're going, i.e. speed traps, etc.

 

My speedo indicates about 3-3.5 mph less than my Garmin. As far as the odometer, we took a tour through Tennessee back in July. Garmin indicated 1,497 total miles, odometer was at 1,560.