Hello,
I have seen that since a while my 1030 shows a wrong speed. At slow speeds my speedometer shows 7-9 km/h and the 1030 round about 4km/h.
At speeds like 20-25km/h the 1030 shows ca. 13km/h and when Im speeding down the mountain 40-45km/h the 1030 shows 25-30km/h.
I have a cadence sensor and a speed sensor from garmin connected.
Its not always like this and somethimes its working correctly.
Any idea?