GARMIN EDGE 705 & GRADIENTS

pthompson73

I own a Garmin Edge 705 which all told is a brilliant piece of kit but I am getting increasingly confused in respect of the GRADIENT % reading......

When out on the road I often refer to the Edge Gradient reading to ascertain the %.....say it x%

Then by the side of the road is a sign displaying the gradient as y%

Then when I get home confused by this discrepency, I refer to MAPMYRIDE and when I plot the section of road, it calculates the gradient z%.

Now I could understand if the % where +/- 1 or 2% of one another, however the variances are wildly different.

Has anyone had similar experience of this and which one is the more accurate

sungod

the garmin takes quite a while to show a reasonably accurate gradient, imho unless it is a long steady gradient the display figure is useless - i remember going up a few hundred metres of fairly steady 12-15% (based on distance and altitude gain shown in the data points), but the garmin was still only reading 10% by the time i was at the top and was claiming below 7% for the first half which was where the steepest bit was

post-ride calculation based on exported data with software like ascent, or just by hand, is much better as the lag caused by the smoothing filter in the garmin can be eliminated

road signs, i think they show the maximum gradient, so on a varying slope the sign could be overstating the gradient much of the time

maps, online or paper, if it's a long climb then you can get fair accuracy for the average, but over short distances there won't be enough altitude resolution to be accurate

pthompson73

Cheers for the the information it helps clear up a lot of the questions the edge causes in that respect