Small screens.

Do you use reading glasses? Stick-on bifocals work great with non-prescription sunglasses. For example.





Garmin bike GPS devices have 12-16 hour run times, can be seen in bright sunlight, are waterproof, and have backlights for night riding.

You can quickly draw a course on ridewithgps.com, and upload the file to the Garmin. Then you follow the course line on a map that orients to your ride direction.

Garmins aren't perfect. Mine occasionally locks up, but just powering it back on lets me continue. I no longer bring paper backup maps.

I got my Garmin Edge 705 for the mapping. But I found I like to see the stats that are recorded from my rides. It shows the track on a map, the grades on the climbs, and my speed, heart rate, and cadence.