Actually it is for security purposes...think of all the speedos that would be modified if they were able to be taken apart for eh...SERVICE! HD will send you a new one properly calibrated (and you could "Warm it in the Sun" or low oven, then seal it up real good before replacing it) to put on your bike. Yeah, an expensive solution, but how do you measure piece of mind, ease of use when a cloudy Speedo is staring up at you?