Mobile Apps & Web

Garmin Connect Web Speed graphs

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Speed graphs

Former Member over 10 years ago

Can anyone tell me why the basic plot of speed against time (or distance) for a ride is much more jagged than the much smoother graph seen when you do a 'virtual journey' along your route? (the one where you press the Play button to start this journey) Also, why is the first graph so jagged anyway; do our speeds vary that much in fact? Or does this signify a problem with connecting to the satellite? I have to say that while going along I notice that my speed jumps all over the place - but hey, maybe it does! (altho this is not borne out by my conventional cycle computer).
Finally, I did a ride yesterday and on my way home I made a 'comfort stop'. My graph shows that, not only did the clock not stop running, but also it seems that I was still covering some distance! Including locking and unlocking by bike, this stop must have cost me at least 1 minute, maybe 2. Yet the graph of this journey shows no such stop - indeed, it shows that my speed didn't drop any lower than about 13 kph!!! While peeing?! And the two times (total elapsed and moving) differed by only 5 s after all that. Something ain't right!

0 Former Member over 10 years ago

Not sure if this is the same problem but speed graphs of my runs recorded using my 305 are also very jagged (unlike the route lines displayed on the map). Makes them pretty much worthless.

Wasted some time exchanging emails with Garmin tech support about this, but it just looks like they don't 'smooth' the raw data when generating the speed graphs as much as they do when generating the map plots.

0 Former Member over 10 years ago

This is all very interesting! I went on another ride today and at my furthest point from home I stopped for over 5 minutes to see what my gadget (Edge 200) would do. Altho I wasn't going anywhere, the Edge was still clocking up the distance, albeit slowly, while the speed shown was varying between 0.2, 0.0, 0.3, 0.1 kph as I watched it! But the weird thing is that, having downloaded the data to my computer, the jagged speed graph shows that for 7 minutes I was travelling at about 10 kps! I have been comparing my new Edge with a conventional cycle computer and I have found, over a number of journeys, that sometimes the Edge reads more than the conventional gadget and sometimes less. I still wonder if this is something to do with how the Edge connects with the satellite. Today, it was under-reading (despite the extra km it clocked up while I was at rest!) and I was riding on a leafy canal towpath. Yesterday it over-read, while I rode up a main road in a mixture of urban and rural settings, and with few trees. Does anyone else have a view on this?

0 Former Member over 10 years ago

I went out yesterdayfor a jog, uploaded info, Connect indicated that in several places, my pace was shown as 1 min/km; I wish!!

0 Former Member over 10 years ago

Hi COLCHTC. That's grossly inaccurate! Are you going to tell Garmin about this?
Hi JM5678. I forgot to mention that my routes, according to Garmin, cut corners on the roads, and also the map tells me that for a lot of the time when I thought I was sticking to roads, I am in fact riding on the verges or thru people's houses! Is this your experience too?

0 Former Member over 10 years ago

Often that is the case

0 Former Member over 10 years ago

Hi JM5678. I forgot to mention that my routes, according to Garmin, cut corners on the roads, and also the map tells me that for a lot of the time when I thought I was sticking to roads, I am in fact riding on the verges or thru people's houses! Is this your experience too?

Presumably my speed is somewhat lower than yours, which perhaps makes it easier for the watch to get an accurate fix. Anyway, zooming in on the route of my last run, it looks pretty smooth, although I can see that in at least one place it's put me on the opposite side of the road to the side I was running on.

But that's only out by a few metres. I'd be more worried if the line wasn't smooth, but it is, so overall I'm happy. Although the speed graph is, as usual, hopeless.

http://connect.garmin.com/activity/530618298

0 Former Member over 10 years ago

It may be that I'm being pedantic about the route sticking to the roads - as you say, if it's out, then it's only out by a few metres. I notice that on your run, there are a number of places where the gadget has cut the corners. I'm totally new to these things, having only used a TomTom in my car before now! So maybe this is what GPSs do? But what about these speeds? At least one person I have spoken to thinks our speeds really do vary like it appears, and I've no way of proving or disproving this - apart from using a conventional cycle computer (a Crivit, from Lidl) on the handlebar beside the Edge. The Crivit appears to hop around much less as I'm going along, but maybe that's because it does its calculations of speeds over a longer time period than the Edge? If that's so, it would have a smoothing effect. This is a ride I did recently on the Monsal Trail in the Peak District: http://connect.garmin.com/activity/530377658

0 Former Member over 10 years ago

This is a ride I did recently on the Monsal Trail in the Peak District: http://connect.garmin.com/activity/530377658

"You do not have sufficient privileges to view the activity with id 530377658" :(

(I think you need to change the 'Activity Privacy' setting if you want to allow others to see it.)

0 Former Member over 10 years ago

I notice that on your run, there are a number of places where the gadget has cut the corners.

Can you point out an example? Because sometimes the pavement does cut the corner, and it's not obvious from the map eg. the junction of Crockhamwell Rd & Nightingale Rd.

Having said that, the following is is from my 305 manual - I don't know if there's an equivalent setting on your device you could try changing to see if it helps:

Data recording controls how the Forerunner records detailed data for your runs or other activities. By default, the Forerunner uses Smart Recording to record your movements and create detailed history. Smart Recording picks up key points when you change direction, speed, or heart rate.
You can also record data every second. Doing so creates the most accurate record possible of your activity. However, with this setting, the Forerunner can only record up to 3.5 hours of detailed data.

In the menus it's under "Settings / General / Data Recording".