Because I thought I could
Join Date: Dec 2004
Location: Wash DC Metro
Bikes: November, Trek OCLV, Bianchi Castro Valley commuter
I think any info you take from this site and survey needs to be tempered with more hand-on data. To start, search the threads here and in the commuter, touring, and long-distance forums for opinions on real-life uses of GPS on bikes. Consider narrowing your requirements to focus on a particular need- is the device intended to provide the bike equivalent of a car navigation system with on-demand routing; play back turn-by-turn directions (electronic cue sheet), display ETA/miles to go, and provide assistance to get back on track; record data from a ride for post-ride playback and analysis, or all of the above? (or something else). how much do you want to leverage other systems and sites (google maps for example), vs. creating a more integrated but proprietary solution. In the case of using a smart phone with display and GPS, consider mounting, power consumption, and device protection (a bike is a high vibration environment).
I'm trying an Android with the Google MyTracks app and Google Maps and ridewithgps.com for display/analysis. If I just want a recording, start the app, turn off wifi/phone (airplane mode) and stuff it in a baggie in a jersey pocket works. If I need occasional display, I can probably cobble a mount using a RAM Mounts bike mount and their "Universal" HT (radio) holder but I still need weather protection (which limits screen access) and power consumption becomes a problem if I want full-time display. I think Trimble sells an app that does turn-by-turn playback, haven't researched that one fully yet. At the other extreme, a pack-of-gum-size Holux GPS receiver coupled with ANYTHING that can record and store the GPS NMEA string (via bluetooth or optional USB cable) is sufficient for post-ride playback.