I know a lot of the 41 uses strava and there are some tech-savy people here, so it's worth a try...

I have been using strava, both the bike and run apps, on my iPhone 4 for over a year. It's been pretty accurate.

But about 1 month ago it lost its accuracy. Entire sections of runs/rides would be lost. Even when not lost, the route would not be quite right.

I am pretty sure the problem is not with strava per se but rather the GPS in my iPhone has lost its accuracy. It is off sometimes with the google map app.

Any suggestions, short of returning or upgrading my phone?

Stupid question here, but are you sure your GPS is turned on? Phones have two ways of transmitting location to services like Strava or any other map-based site: GPS or triangulation using available cell phone towers in the area. A GPS reading is much more accurate than determining your location via cell towers, so it's possible that either a setting got changed in the Strava app that's causing it not to use your GPS or your GPS isn't turned on or configured correctly. Of course, there could also be a bug in the app, but those usually get reported pretty quickly if a lot of folks are having issues.

The only external things, that I can think of, that might be affecting accuracy is phone placement (on your person) and obstruction by overhead trees - the less between your phone and the clear blue sky, the better.

Internally, short of a hardware malfunction that you can't do anything about, I can only think of a couple things: 1) make sure your date and time is correct (so your phone knows where GPS satellites are supposed to be) and 2) see if there are any user settings relating to aGPS (assisted GPS - uses cell towers to help determine positioning).

Pretty sure GPS is turned on. I get "GPS Signal ok" when app is on.

And GPS is off for map apps.

I know it's a phone problem and not a strava problem, but since there are many strava users here I figured someone else has the same problem and maybe a fix.

Could it be that the satellites are not being picked up due to foilage or heavy clouds if that be the case???? Just a thought.

They recently changed how the GPS was calculated. Another thread was complaining. However, they fixed it so be sure your app is updated. Maybe you got caught in the gap. My Galaxy Note 2 is the first phone I've had yet with a reasonably reliable GPS. I've had a few that were horrible prior to this one.

Could be a cell reception/tower issue as well. The iphone requires cell reception for the GPS to properly work. In my area there is a dead spot where service usually dropped and the would be picked up by another tower. This caused myself and a friend issues with both strava and run keeper.

When you have this problem, does the route still look normal and you just have reduced miles, or does it delete entire sections out of the map as well?

I had a buddy that had this issue, he'd go 50 miles, get home and strava would say he went 45. This happened to him a few times, each time he emailed strava and they corrected the issue. I don't believe they knew what was causing it. They tried to blame the wahoo fitness app. The problem has went away now with recent updates to strava.

I found that when I place my iPhone 4S with the screen facing outwards (away from my back) it's more accurate than when the screen is placed against my back. I can only assume it has something to do with the GPS reception. But that's just me and I ride flats with little tree cover here in South Florida.

During your rides are you taking photos with the Instagram app? It sometimes doesn't play nice with other GPS dependent apps.

When things get buggy on my iPhone, I clear out the opened apps in the tray, then restart (soft reset) the phone. If that doesn't fix it I perform a hard reset.

Hmmm. My old iPhone gets GPS fine with no sim card or service contract whatsoever after getting a new phone. It does everything except work as a cell phone or get data over the cell network. Web, email, app store etc all work over wifi when in range and connected. Off wifi, GPS still works fine but you won't see maps with most apps which usually need to download them in quasi real time. You need an app with resident maps.

From what I have read when I was trying to pin down the issue; apps use a cell service to pin down a location quicker https://www.macworld.com/article/1159...ion_works.html
I think in my case the tree cover/tower switch/being in a small river valley cause the lose of coverage and subsequent loss of data. Here is a screen shot of a ride where this happened. (Always happens on this route with iPhone, upgraded to a Garmin 500 to avoid this)

Here's an unlikely fix, but perhaps it could be your problem.

Have you changed the location you keep your phone while riding? I used Strava through my Android in my back jersey pockets and it was incredibly precise. Then one day I rode around my neighborhood a bit wearing basketball shorts with no pockets, so I just jammed the phone in the front of my waist band. Turns out that my body must have messed with the signal when I was hunched over riding, because the map (although very loosely correct) had me driving over houses when I checked it later. If I had to estimate, I'd say it was around 50 feet off just because of where I stored my phone while riding.

Try this:

https://strava-tools.raceshape.com/snap/

"Use SNAP to adjust the ride so it represents the road."...

There's very little documentation on the site, so you may have to hack around a bit before you get it working...

I've only tried it on one of my old rides, and it seemed to be quite good. Going forward, I'll only use it on newly posted rides - if necessary.

What it (basically) seems to do is pull your track back onto the nearest road, so you can re-load the ride to Strava and see if it picks up the segments (etc.) correctly.

Perhaps someone else can provide better info about this service.

Thanks for the tips, everyone. I will look into the suggestions and see if I can find a solution.

But to be concise, the GPS in my phone is off (by roughly 35 feet, at least in my home, this is a NEW inaccuracy). So it's my phone not strava directly. Will try reset trick and if nothing else works I will consider the SNAP suggestion.

Of course my iPhone 4 is getting a little old so the ultimate solution may be to upgrade to an iPhone 5, but I figured it's best to wait until the 5s comes out in a few weeks and the price on the 5 will drop like a stone.

Addendum. Just for fun, I went to google maps and zoomed in on my house. Every few seconds it moves my current location. Approx 20-40 feet, and none of these locations are correct. This bouncing around of my gps position explains why my strava run segments have looked so zig-zag.


Any further suggestions are appreciated.

Have you updated the app recently? Sometimes that'll fix bugs.
Also, text messages and programs like Instagram can completely crash Strava (not sure why), at least on my phone (iPhone 4S). I check my Strava app every few miles on my rides because It has crashed a few times. It restarts and does that, "You have a ride you haven't finished. Resume or Finish?" or whatever.

Yeah, GPS has it's limits when it comes to precision, although it's actually amazingly precise considering the satellites are orbiting 12,000 miles away.

I just tried that on the two rides where I had issues lately. One ride was missing an 11-mile segment - SNAP got it back for me. The other ride showed my average speed on a segment as 15 mph, and I knew I was faster than that. I used SNAP to reset it and the speed went to 19 mph - much better. Thanks for the tip!

Google "iphone gps calibration" and follow some of the links. It may help in your situation. For Android users look for "GPS Status & Toolbox" app.