Phone not inserted properly into dock, this is just a demonstration. :)

When placed in dock:
Turn off WiFi
Turn off Auto rotate
Turn on GPS
Brightness 100%
No screen timeout (35791 minutes roughly equals 24 days)
Speak "Bike mode"
Start bike app (MapMyRide)

When removed from dock:
Turn on WiFi
Turn on Auto rotate
Turn off GPS
Automatic brightness
Screen timeout 1 minute
Speak "Leaving bike mode"

Apps used:
Modified AnyTag

Materials used:
Garmin GPS holder from ebay
No-name case from ebay
NFC-sticker (NTAG203)
Some super strong double sided tape
Some spare parts lying around the house.
Total cost: around 100SEK (15USD)

Loading more stuff…

Hmm…it looks like things are taking a while to load. Try again?

Loading videos…