It seems I cannot complete a ride without having my Cateye or my Garmin (or both) go crazy and compromise my max speed data. Mileage, average speed, elapsed time, all seem to be OK, but, at various times, one or the other (Cateye or Garmin Etrex CS something or other) make an erroneous max speed reading - 184 mph, 78 mph, whatever.

Once in a while, it happens to both at the same time, more often, though, each will, during the course of a ride (say 60 miles) just go haywire.

Very often, it happens on a steep decline where I am really interested to see what speed I (well, the bike) achieved. I never see this occur, since none of this is so important that I would risk an accident to observe either gizmo while in the process of descending a hill.

There seems to be no pattern in terms of where this occurs. Any thoughts welcome.

Caruso