Looking to see how accuate the speedometers are for you guys. Mine is reading way off. I put a bicycle speedo on my XF200 to get a more accurate reading of speed/distance. I was driving mine up to my Mom's house with my wife behind in our car and she said that I was only going 55 mph....and backing up traffic. I was showing 64 mph on the bicycle speedometer but 70 mph on the Qlink speedo. I can recalibrate the bicycle one but I'm thinking that I got a speedo intended for an XP. Does it stand to reason that a XP speedometer for 21" wheels on a 17" wheeled XF would show a higher mph than what I am truly traveling? Is anybody else having that wide of a margin between indicated and actual speed?