From numerous postings and corrected speedometer face plates, it appears most DL1000 speedos read about 8% high, with a linear tracking throughout the (normal) speed range. To correct the speedo, all that is needed is to length the pulse from the speedo sender on the front sprocket by this amount. Microchip PIC 12HV619 microcontrollers are (currently) $0.92 each. It simply reads the pulse from the sender, multplies the pulse length by 108% (actually multiplies by 138, then divides by 128 ), and outputs this pulse on another pin. The only other compnents are a resistor and capacitor to reduce the 12 volts to 5 volts for the PIC - total cost is <$2US. In testing with a GPS, the corrected speed (7.8%) was right on for a partially worn TrailWing rear tire.