I just got myself a 2014 Sportster Superlow and haven't had time to check the speedometer. How accurate is it. I had a Honda Shadow Spirit that was dead on. I would say the late model Sportsters may be more accurate.

 

Well my 2013 48 runs about 3 to 4 mph slower that what it says at least that is what I can figure by passing those roadside radar detectors that the Sheriffs put up, the ones that tell you how fast your going..

 

By chance I checked my 2014 XL1200T Sportster speedometer against the GPS yesterday. Identical readings at 50MPH. Remember that a GPS gives something of an average, so you should do a constant speed for about 30 seconds when you check it against the mechanical speedometer.