I have googled and researched and keep seeing the same thing....that Strava does NOT need data to work. You just cannot upload to Strava until you are on wifi. I have a purchased Samsung galaxy s5 that is deactivated since I upgraded to an s7. I would like to use this phone as a bike computer. Today I started Strava recording when I left in my vehicle for work only as a test and about 150 miles later (I travel for work) I decided to wake my phone up to see the progress and it said I had traveled about 40 miles and was going over 1500 mph down the interstate! Just now I fired up Strava again and put the old phone in my pocket and rode about 1/2 mile around town probably averaging 10-14 mph. When I got home Strava said I had traveled 0 miles and averaged 3 mph. Any ideas? I will say, since I only plan on using this old phone for this purpose (and to save battery), I went in and disabled a bunch of the battery hogging apps by google (all of them). Could I have disabled anything that is affecting Strava? I don't understand why it won't work.

Can you inspect the raw data? Perhaps the gps is sucky and you have missing data. You could always install an app like Locus and run them both while traveling. If they both have issues, it might be the gps.

I have locus pro and plan on trying it today. The gps worked well before I deactivated the phone. I also installed IPBIKE last night. I will toy with it some more.

Well heres an update. This morning I turned on Locus Pro and started recording a track as i rode my bike around the block. When I stopped and then hit save, It had a start line to my first turn then it made a bee line to my current location completely skipping the ride around the block. The last time something like this happened was when I didn't save my ride on my garmin edge and then when I got home and turned it on to upload the garmin made a bee line from where I was riding to my house. I understand why that happened but what just happened on locus has me baffled because I never turned the unit off and then restarted it. I simply stopped my ride and hit save and that was the end result. Here is the link I exported to strava so you can see what I mean. https://www.strava.com/activities/696665225