Originally Posted by
terrymorse
Unwarranted concern, and wasted effort. Technology has addressed both of these problems.
Most GPS bike computers will also take speed and distance readings from a wheel sensor. The well sensor reading is a "back up" for when the GPS signal drops out.
The Garmin unit will auto-calibrate the speed/distance sensor by comparing it to GPS readings.
Clear your handlebars and your mind will may follow.
__________________
Vintage, modern, e-road. It is a big cycling universe.