Garmin Edge and wind

mattitheowl

Anyone else had any issues with the gradient figures on windy days? I was going up a steady 6% today (known from previous rides) and the Edge was reading from -2 to 8% and jumping around. I wondered if it was the wind playing havoc with it somehow or if it is something more sinister.

Cleat Eastwood

Its a well known fact yo can get lumpy wind and flat wind - you must have been on the lumpy stuff.

mattitheowl

lol. I just wondered if it was something to do with the barometer in the unit and the wind causing fluctuation. I don't know about it being lumpy, it felt like I had hit a wall at one point.

stephenlinden

I know what you mean about the wind. 3-4 miles into a headwind on a pan flat stretch of road (just fields no protection) and I struggled to keep going at 12 mph. Went over a motorway bridge and I was peddling but the bile felt like it was stationary.

Your theory about the barometer might have some merit though.

lc1981

stephenlinden wrote:

I know what you mean about the wind. 3-4 miles into a headwind on a pan flat stretch of road (just fields no protection) and I struggled to keep going at 12 mph. Went over a motorway bridge and I was peddling but the bile felt like it was stationary.

That's not going to explain why a Garmin was misreporting the gradient of a hill though. We find it harder into the wind, but a satnav shouldn't!

Cleat Eastwood

maybe as your battling the wind you flick the bike to correct side gusts which maybe garmin reads as bit of a flat - just a thought - a rubbishy thought, but a thought none the less.

alihisgreat

I've yet to use the gradient function.. might have to try it next time I'm out.

Mikey23

I have my altitude % set up on the front screen of my 500 and it usually pretty consistent. But I have noticed that it occasionally goes AWOL and will put up silly figures. On an extremely hilly Cornish sportive it kind of gave up and got stuck on zero for ages even though I was climbing 15% at the time. Don't think it was windy and the contour printout when downloaded on strava was ok.

mattitheowl

It's been pretty good so far to be honest and was fine on the same hills on Wednesday but the only difference was the very strong wind today. And it seemed that the stronger the wind the worse the fluctuations. If I was climbing and started going into a headwind the % would drop and even have me as going down a couple of %, then climb back up as the wind died down. It was really odd. It was bang on out of the wind or with a tail wind.

careful

The Garmin measures gradient by an internal barometer that interprets a reduction in air pressure as an increase in altitude and displays this as a gradient. Since wind is itself variations in air pressure, it figures that it would get confused. The tiny hole that allows the air in and out can also get blocked (sometimes by water ona wet day); this also causes whacky readings.

markp80

I guess if the wind is blowing across the hole it could also set up a venturi effect which would reduce the pressure inside the casing momentarily, making the unit think it was going downhill.

MarkP