Originally Posted by Kopsis

Many people will find that a basic bike computer for real-time speed and distance coupled with a smartphone running a GPS tracker in your jersey pocket with the screen off is an extremely effective solution (especially if you pick software that supports stored map files so you can put the radios in airplane mode). If disposable income is a consideration, I would only suggest moving to a Garmin-type solution (or a bike-mounted optimized smartphone) if you need to add heart rate and/or power meter data for structured training purposes.