iPhone #GPS #fail

There’s a double edged sword going on with modern smartphones. On the one hand they can do loads of stuff, but the flip side is that they might not do certain tasks as well as a dedicated device. For most tasks the compromise might be acceptable, but what are they like for tracking your bike rides? How do they measure up to dedicated GPS units?

In this post I’ll share the findings of a little experiment I did, which involved my friend’s iPhone 4S running the Strava app, my Android phone, a Samsung Galaxy S2, running the MyTracks app, and my Garmin Edge 800.

The experiment was initially devised to determine if Strava segments were being interpreted differently according to variation in the gpx tracks produced by different devices. The idea was for a group of riders to ascend a hill together, and see if strava interpreted the segment timings correctly.

This post is an off shoot of that experiment, mainly because I thought the issue was worth highlighting.

Track recorded with Garmin Edge 800
Click to enlarge

Here is the Garmin track, which we can use as a reference. It follows the road perfectly, and all segments are picked up by Strava, every time.

Track recorded with iPhone (4S) Strava app
Click to enlarge

Here’s the iPhone 4S track. It’s all over the place. It barely follows the road any point, and Strava did not recognise this as the segment it actually covered.
If this is the quality of the GPS tracking on iPhones – don’t use one!
Just stick to Angry Birds or whatever….

Track recorded with MyTracks app
on Samsung Galaxy S2
Click to enlarge

Here’s the track recorded by the MyTracks app on my Samsung Galaxy S2 (Android).
It’s very accurate, and like the Garmin track, never deviates from the actual route taken. Strava recognised the segment and ranked it as an identical time to the Garmin.
(The garmin was mounted to my bar, and the phone in my jersey pocket)

I took a closer look at that iPhone track, and found this little delight (below).
I have no idea what’s going on here. We were travelling from the East, following the road by the side of the river. The iPhone starts daydreaming and wanders off the track, only to snap out of it and suddenly jump back to the road at a later point (the zig zag bit).
The garmin and android tracks had no such oddities, and were consistent for the entire 58 mile ride.

Serious errors on iPhone 4S track
Click to enlarge

Was this iPhone drunk? Click to enlarge

Rock solid Garmin track – sticks to the road. Click to enlarge

If you’re serious about tracking your cycling, there is no better option than a dedicated unit such as a Garmin. Smartphones can give you a taste of it, and on the basis of this limited evidence, it would appear that Android does it more effectively than Apple. But they would both suffer poor battery life anyway, so the Garmin still wins.

There are loads more reasons to ditch your phone and get a proper GPS for your bike.