Navigation-Fest – Edge 820 and others do 9 hours of trail navigation

Capital Ring London-RideI was bored so I loaded up a 120km GPX trail map.

In the end I was out for about 10 hours and 145km of trail, hill and the occasional road. I did some pretty long detours…some of which were my fault.

I suspected the battery wouldn’t last so I also had some reserves with my 920XT (course loaded just in case) and a MIO 505HC (course loaded) which I’m not really always happy with. The BePros were switched to my MTB within the usual 5 minutes, the sturdy aluminium frame was dwarfed in weight by gels and liquids, the HRM-RUN strap was on. What could possibly go wrong?

Bearing in mind that all that I wanted to do was complete this particular route in one day AND get a complete power track. That was my exercise and my data goal. Simple huh?

Garmin Edge 820, Garmin Edge 810The Edge 820 is widely reported to be slow at loading up a course. This especially large/long course took somewhere near 5 minutes to fully plan. However the course DOES display much quicker than that on the screen and you can, sort of, follow it for a bit while the planning/calculation is going on. The MIO takes a good minute (a very good minute ie longer) with the same course and also appears to go into slow mode immediately afterwards whilst it is doing ‘something else’.

When it’s sweet, it’s really sweet. The Edge 820 had me navigating perfectly for over 5 hours. Although I have some vague familiarity with the route I really don’t know all the turns, so the edge got me started at a cracking pace. I was 36 minutes faster than previously on the first half – helped by good navigation AND, of course, by previous familiarisation.

The Edge 820 was used with turn-by-turn (TBT) navigation – GPS+GLONASS, HRV/per-second recording, HRM and PM. It lasted between 7.5 or 8.5 hours, I’m not exactly sure – you’d have thought I could tell from the FIT file but the reality was too complex for me to decipher, so I won’t. Let’s say 8 hours 15 minutes for those of you who want a number.

Polar M450, Garmin Edge 820, Garmin Edge 810, MIO Cyclo 505HC
Polar M450, Edge 820, Edge 810, MIO Cyclo 505HC

The Edge 820 seemed to turn TBT off in certain circumstances. And then a reload was required. At the Olympic Park I thought the Edge was broke as everything went super, super slow. When I tried it again later in nav-gadget desperation it was Ok if I left it alone. Various navigation settings seemed to have turned themselves on or off.; maybe it was me. Not sure what went on nor quite sure how to change them back.

The Edge’s screen size is fairly small. However the clear screen/good resolution made it pretty good for navigation in my opinion. It seems to have lots of navigational options – more than I’d ever use.

The one thing that was unusual was that it insisted on drawing a straight pink line from where I was to the next point, as well as the actual route. That was useful in giving me an indication of generally what direction to go in but otherwise a little annoying. No doubt it could be turned off if I knew what is was called. I’m sure it wasn’t on at the start (whatever it was). Oh well.

Even with GLONASS on the 820 seemed about 4 or 5 metres out in the sense of there sometimes being that equivalent amount of delay in telling me I’d missed a turn. Also sometimes when I was SURE I was following the route under tree cover it told me I was 4 or 5 metres out. On the other hand I was sure I was going the right way when I blasted off 2km down a towpath the wrong way…that shows something about my sense of direction and general intuitive navigational abilities.

The 920XT lasted about 9 hours. 8 hours with GPS+GLONASS, HRV/per-second recording, HRM and PM. Then, when I realised the battery was running out I switched on ULTRATRAC and turned GLONASS off to eek out the extra hour or so. So much for the full backup track. Of course there are other power saving features I could have used. I never used the 920 for navigation, although I had the map on it just in case.

Polar M450, Garmin Edge 820, Garmin Edge 810, MIO Cyclo 505HCThe MIO 505HC’s battery lasted more like 4/5 hours. But it was the beast that got me home when I turned it on for the last stretch and it recorded the last part of the power track (phew!). Unfortunately I had unpaired my HRM with the MIO for some reason so I have an incomplete HR track (Grrrr!).

Providing you stay ‘vaguely on course’ the MIO navigates quite well. Once you go too far off piste it goes a bit pear shaped and gets confused. Occasionally it comes up with a Windows error for no apparent reason.

The BePro PMs just worked. Lots of battery left.

Life Saver: Combined the resulting data files using the awesome fit file repair tool. It combines, merges, fixes AND makes a mean Latte. so it combined two fit files and added on the TCX file from STRAVA that came via MIO Share (MIO seemed to have turned off FIT export…Grrrrr).

Analysis: Not much to analyse really. Golden Cheetah told me I’d done a Zone 1 ride for a long time. I kinda knew that. Although surprising how many times the zone 4 alert popped up on the Edge for the hills and harder bits in general. I failed even to extend my Zone 2 power duration PB. Oh well.

Other issues:

  • Cornering on near-flat front tyre. Ouch. I always wanted a good excuse to buy a new brake lever.
  • Danger/Stupidity. My rear has had a slow puncture for months. I liked living on the edge to see if it got me around.
  • Not carrying a pump or repair patch and instead relying on an ancient patched inner tube as a backup (that strategy sort of worked).
  • The trusting generosity of a random cycling bloke who gave me his pump and sped off and just said ‘post it in that letterbox over there when you are done’ … awesome free pump!!  (Joking, I did post it obviously).
  • Sugar. You can only drink so much Lucozade Sport. There should be a dental-law against drinking more than 4 in a day. (Actually there is, in Lithuania. I was in London.)
  • Dog owners. Actually most of them seemed pretty good and realised that it was their responsibility to keep their animals under control. Wonder never cease.
  • Dog mess not cleaned up – Worst in SE London especially anywhere near a train line, best in SW London where there are most dogs and best in N London where dogs appear to be banned.
  • Multiple dogs. How many dogs can a single person own? The answer is at least 8. Wow.
  • Extending leads. How long can they be. Answer: always just that little bit TOO long for safety.


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