Mine started acting up yesterday at around 700 miles on the bike. I have noticed two different failure modes. The most common is it simply sticks at a speed and will not move up or down with road speed changes. This seems to have a mechanical aspect to it as sometimes hitting a bump or tapping the gauge will cause it to unstick, but this is usually short lived.
The second mode is a more erratic behavior. It's as if the gauge selects a new speed as "0" and adds your current speed to this new base. I have had this happen only twice. Once it does this, it may increase the base speed yet again, but the needle still responds to changes in road speed. It did this today. Two increases left the base speed (when bike is stopped) at 75. Running with traffic down the highway (60-65?) had the needle running over the top of the LCD read-out. Tapping the glass does nothing once this happens. Turning off the key and restarting the bike is required to get the meter to return to zero. The gauge may work for awhile after doing this.
I'll have to get it into the dealer soon. Both days were pretty warm with temperatures in the high 80s before I began having problems. It was cooler in the morning when I left both days and I did not have problems until it got hotter out and the bike had been running for well over an hour, but with only two similar days with this happening so far, it is hard to tell whether heat is a factor.
This gauge set looks like it might be the same as the one used on the Rocket 3 Touring bikes. The smaller gauge on the R3 appears to be re-purposed for fuel level instead of a Tach. Has anyone heard of problems with the R3 speedo sticking? My bike has a build date of Feb 2010. Do those of you having this problem have a similar build date?