Originally Posted by
slcbob
A guy on the REI reviews had issues with the 705 woefully underestimating distance, to the tune of ~30%. This seemed odd to me. Did anyone else have that problem? Haven't heard anything bad about Polar in that regard.
The "self-calibrating sensor" I assume uses the GPS signal to calibrate the distance/revs, then the unit can use the best of both worlds as a couple have suggested here. Perhaps REI man screwed that up.
I suspect the poster of that nonsense had been used to an inflated indication of distance/speed that is easy to do if you specify the wheel size to be larger than it is. If you get used to that inflated mileage/speed and are then brought down to earth by the device that won't lie for you then you may be inclined to claim it inaccurate. If you actually ride at 16mph but you've been lead to believe you were doing more like 21mph then when the Garmin tells you you were going 16mph you may not be happy.
I'd say the Garmin, and EVERY other GPS unit out there can be expected to be better than 1% accurate at distance and usually speed.
Brian