GoKawiilSmartphones can substitute for dedicated bike computers, with caveats
Cyclists can use smartphones with mounts and apps like Google Maps, Komoot, or Ride with GPS for navigation and GPS ride tracking instead of buying a dedicated bike computer. An older phone can be repurposed as a bike computer by loading routes over Wi-Fi, since offline navigation and GPS recording don't require a SIM card, while a smartwatch can supplement the setup by tracking heart rate and fitness data.