Garmin Edge 705: 15 Months of Beta Testing

My Garmin Edge 705 is officially broken and going back to Garmin for replacement. In the past week it has had an increasingly difficult time receiving GPS signals (ANT+ sensors continue to work fine, so it’s functionally the same as a pre-GPS bike computer). It’s easy to watch the deterioration because every time it loses the GPS signal an error message pops up and the unit beeps, which was happening every minute or two on a 65 mile ride last weekend. At this point the errors have stopped because it the unit never acquires a GPS signal.

Now that I’ve used this for a few thousand miles and updated the firmware half a dozen times I have some updated impressions

• The Edge provides all the instrumentation and data logging I could (currently) want. That is to say, it’s an excellent “head unit” for ANT+ sensors. I had expected the GPS features would be more important, but I use them only occasionally when riding my usual routes. All the realtime data is quite addictive and nearly justifies the price of the unit
• The firmware was incapable of following a cue sheet (e.g. a GPX file) type of route until about six months after the product was released, which is to say I did my first ride with directions in September 2008. Cue sheet style navigation is still quite buggy and unreliable (when it works it is impressive, but it’s more the exception than the rule that it works at all). Whether any given GPX file is usable for navigation generally depends on what type of software was used to create the GPX file. GPX files from Garmin MapSource and Bikely work well, so if you are willing to invest the time to author your own GPX files the unit should be able to navigate the route (this was not the case when it was released). GPX files from other GPS receivers often never work (e.g. the turn by turn directions will have all 50 turns listed on the route, but zero feet of distance between them so the navigation ends as soon as it starts), so most of the GPX files I download from my local club’s web site load do not work on the Edge (loading GPX files into MapSource first sometimes helps)
• The handlebar mount is completely inadequate. The mount breaks if the zip ties are too tight. Even if the zip ties are not tight, it still breaks every few months. All mounts seem to break in the same place (the inner plastic piece that slides into the Edge unit itself splits). Most experienced Edge 605/705 users I see have had this problem and some have devised interesting homebrew solutions to mitigate the risk of the unit falling off the bike at speed (e.g. epoxy a metal loop to the back to catch the unit when the mount breaks, zip ties around the unit and stem, etc.). Fortunately the mounts are not too expensive, so I keep several on hand and replace them every other month
• Battery life is ever-decreasing as the unit ages. I ride about 200 miles/week and charge the unit on Friday and Sunday nights (previously it could handle being charged only once a week). This is expected, much as with an iPod because the sealed battery loses its ability to hold a full charge over time (and has a limited number of recharge cycles, though this is probably not a big problem as it is a new-style Lithium-ion battery)
• With subsequent firmware updates the Edge has become much better. Before breaking it was able to acquire a GPS signal in well under a minute (sometimes just a few seconds if my previous ride ended in the same place) whereas it needed 60-120 seconds to find a signal in the when I first started using it
• The backlight feature is excellent for night rides, and the reflective LCD display is very good in daylight
• I’ve gotten used to the spindly typeface, though I still don’t like it

What I would like to see in the next Edge product (FWIW):

• Do not release the product until it is ready and all the promised functionality works. Nobody has challenged Garmin in the cycling-specific GPS receiver space, so it’s worth having a stable/working product at the time of release. I don’t know the specific demographics of Edge users, but my anecdotal experience is that people who buy $500 bike accessories expect the product to be well designed and reliable (the Edge 605/705 was well designed, but had software that was far from reliable). This is more of an iPod type product (premium, polished, with a product cycle measured in years) than an expensive mobile phone (fashionable, extremely buggy, with a product cycle measured in months)
• Lanyard loop (like most mobile phones and digital cameras have) to secure the unit in case the primary mount fails
• More reliable (perhaps not 100% plastic) handlebar mount
• Robust GPX file handling in the unit itself (e.g. for files dropped in the “GPX” folder). Desktop software seems much better at making sense of “foreign” GPX files than the Edge firmware
• Faster calculation of routes (it takes about 10 minutes for my Edge to parse and navigate a century length route from a GPX file). If this can’t be made faster, at least make it non-modal (route calculation locks up the unit so it cannot be used as a bike computer while it (re)calculates routes)
• Better support for navigating routes from places other than the start (e.g. picking up a 50 mile ride at mile 2)
• A “Return to Start” feature that doesn’t rely so heavily on reversing the course. Most organized rides are loops/circular, not point to point
• Accessory cable to power/charge unit from a hub dynamo (this is really important for brevet length rides and should be simple)
• User interface to force calibration of the altimeter from GPS (so it is accurate before the start of the ride). Might be worth remembering the last n-points where the altimeter was calibrated to speed the process in the future (e.g. my weekly hill ride starts in the same place each week)
• Wireless route transmission is too slow to be useful before a ride. GPX routes are no more than a few hundred kilobytes, so why does it take several minutes to transmit?
• Support for calculation of speed from cadence and cadence from speed for fixed gear bikes (especially helpful when swapping wheels at the track)
• Calculate the number of gear inches and log changes (up/down shifts). I think the GSC-10 sensor provides enough information to do this, and for extra credit it might not require too much data for the firmware to accurately guess the chainring and cog sizes from the changes in gear inches (especially for now-popular compact doubles which have no/few overlapping ratios). Would be interesting to compare shifting strategies on each lap of a crit or circuit race
• When several bike profiles are configured to use “Auto” wheel size, do not recalculate the wheel size each time a different bike profile is selected (store and re-use the previously calculated value). This makes the first mile of riding inaccurate after changing from one existing bike profile to another
• Choice of typefaces for the data fields
• Possibility to have wireless sync to PC (e.g. ANT Stick like the Garmin FR60) and support for ANT+ weight scales (again, like FR60)
• Capacity for North America and Europe maps without swapping microSD cards. Everybody needs/wants the maps anyway, so eliminate the non-map SKUs

Blue sky enhancements

• Support for Bluetooth for mobile phones would be a battery drain but could add more interesting functionality. Most riders who have an Edge also carry a mobile phone, and most of these have Bluetooth support and access to 2.5G or 3G packet networks. The rider’s phone could be used to provide interesting mid-ride data updates, download weather forecasts, receive SMS messages, provide incoming caller ID, and maybe even receive mid-ride safety warnings, last minute course changes, etc. for organized events. It would also be useful to actually know how far away your friends and training buddies are on a ride if they choose to make that information available
• A simple MP3 player would be nice for extended tours, but is clearly non-core functionality. A second micro-SD card could make this easier to manage, and dynamo power would help make it practical from a power perspective. This probably opens legal liability concerns…
• The current form factor is well suited to stem mounting. I find it easier to read on the handlebars and would prefer a wide form factor Edge (somewhat like the Topeak V16 in appearance). If this allowed for a larger battery, all the better! Allowing the display to be rotated 90 degrees would be interesting.