OK. I'm new to the RC51 (just bought mine from a great gent in FL) but I haven't had the chance to ride mine yet (currently in Iraq). I have been looking at the Chain/sprocket upgrade. On my CBR900RR, the optical pickup for the speed was at the front sprocket, and I was told by a Honda technician that as long as the front sprocket was unchanged, the speedometer was "relatively" accurate. Given this, is it reasonable to assume that by not changing the front sprocket (16 tooth) and raising the rear sprocket (43 or 44 teeth) eliminates the need for the speedo healer? Or is the speed sensor somewhere else in the bike and any change will require the box?