Join Date: Feb 2019
Thanked 6 Times in 6 Posts
The speedo being 5-10% "optimistic" is pretty common on most motorcycles and has been for decades. Yamaha sportbikes are notorious for this, people call them dream-o-meters since they tell people their R6 does 185mph. My Valkyrie and TW200 are the same way. It's not an inherent inaccuracy, it's set that way deliberately. However, the odometers are very accurate, and calibrated differently than the speedometer even though they have the same signal. Essentially, the speedometer readout deliberately exaggerates a bit, while the odometer counts true. (it would be illegal for the mileage to run up faster than actual). I used a speedo-healer on my old Z1000 and found the factory error was about 7%, but I'd also lowered the gearing which made the error more like 13%. With a -13% input, the dash speed was bang on when compared to a GPS- but the odometer routinely read 10-12% less than everyone else's on group rides, and less than actual when compared to the same GPS.
I wouldn't mess around with trying to disassemble the speedo cluster. There is no adjustment or anything like that. If it really bothers you I'd get a Speedo Healer, although IMO they're pretty pricey for what they are. The other option (sometimes) is to get a slightly oversize front tire- go to the next profile up, if available. This slightly increases the circ. of the wheel, and can help pull the speedo a little closer to reality.