GPS for Cyclists


by Byron on Feb 09, 2009 at 5:50 PM

David J Schloss wrote this post for us. David is the Director of Aperture Users Network. Photographer. Writer. Cyclist. Find him on Twitter.

Like many things we now take for granted, the Global Positioning System (GPS) was developed for the military–the ability to determine precise location down (with military systems) to inches is a crucial advantage in combat. Early commercial GPS units included a bit of scrambling in the hopes that civilians wouldn’t use the systems for terrorist purposes, but that intentional scrambling was ended during the Clinton administration, paving the way for generations of more accurate GPS devices, including Garmin’s latest foray into bicycling-specific computers, the Edge 705.


While Bike Hugger tested out the iBike system on the roads of Kona, we’ve been using the Edge 705 since its release, and it’s revolutionized training and group rides thanks to several key features–routing, training planning, wireless data transfer and data mining.


Garmin makes its bread and butter through commercial vehicular navigation systems, the ubiquitous GPS systems that help drivers get from Point A to Point B without getting lost along the way.

At its heart, the Edge 705 is a full-fledged navigator that comes with complete street maps for the United States and Canada. (There are entry-level models of the Edge 705 without the included micro-SD card maps, don’t bother with them as the default base maps on the non-mapped version only lists major roads, the sort of routes you’d like to avoid in the first place.

As a leader of group rides for our local club, I’m often looking for new routes but the fear of getting the group lost often curtails my exploration. The Edge provides complete turn-by-turn mapping to any destination, and the device calculates the best routes for bikes, avoiding highways, toll roads and dirt routes.

Several different modes provide different ways to receive navigation–set up the main bike computer to show turn information, look at an on-screen map with directions, or follow along text-based turn-by-turn directions. In any case, the Edge will alert you at each turn and provide directions.

Thanks to my newfound ability to get home no matter where I am, I’ve actually discovered a whole new system of roads and routes. As the Edge plots paths via fastest or shortest routes, it often takes me through areas I’ve never ridden before, which has seriously increased my route variety.

It’s also possible to download routes into the Edge–when I did RAGBRAI years ago I took along one of Garmin’s general-purpose GPS units (before the Edge was available) and downloaded into it the complete route for the ride. At any point I was able to plot distances to rest stops and campsites, helping me better pace the ride.

Websites like provide GPS mapped routes you can download (disclosure: I’m a contributor to the mapping section of the site) into your Edge, which makes it fantastically easy to find a ride when you’re traveling.

PC users can use Garmin’s mapping software to map out routes (Garmin’s Mac offerings with the route mapping are behind their PC software) and maps can be made and downloaded from Google Earth.

Maps are available for Europe and many other regions, and I’ve used the Edge to help me ride across Europe without a guide book or turn sheet in site. Recently I spent an afternoon pedaling around Amsterdam and when I was done just plugged my hotel in and let the Edge route me back home safely even though I had no idea where I was.


For many users the Edge 705 can replace a coach or trainer, thanks to the programmable training features built into the unit. Interval day? Simply create a routine with the rest and intensity splits and the Edge will prompt you when to start and stop. Workouts can be tailor made for things like base miles, minimum speed, climbing goals, heart rate goals, power level averages, distance and more.

The Edge will display all split starts and stops, prompt you (in the case of speed-based workouts) if you’re going too slowly or too fast, let you know when to sprint or rest, and more. You can even record a route and turn it into a workout, riding it to compete against your best time. While in training mode the Edge’s screen displays a graphical bike rider for yourself and for your “opponent” (either your previous time or your set benchmark for the workout), a surprisingly motivating little element.

The top-end Edge model comes with a heart-rate monitor and a cadence/speed sensor to gather real-time cadence data, and to provide speed readings when GPS signal is weak or when riding a trainer inside. (The sensor fits the rear wheel, which  allows the computer to still function when riding a wind trainer with stationary front wheel.)

Garmin also adopted the ANT+ specification for wireless interoperability with ANT+ power meters, which allows power training with a variety of power meters.

Those with multiple bikes can program the profiles of up to three bikes, allowing the Edge to move between bikes and still properly estimate rider calorie burn. Cadence sensors are available as an accessory, allowing multiple bikes to work with a single Edge computer.

Wireless Data Transfer

The ANT+ standard not only allows the Edge to work with wireless heart, power and cadence accessories but allows the device to talk to other units, enabling Edge-to-Edge transfer of workout programs and routes. Show up for a group training ride with your cadence workout on your Edge and send that workout to everyone else in the group. Or (and this is the holy-grail of group-ride leading) create a route and share it with all the other Edge computers in the pack so that no one gets lost when your B level training ride turns into an A level hanmmerfest.

Data Mining

For the gearhead, the Edge provides a huge ream of information. Bike Hugger has already looked at some software programs that help the athlete track their workouts, but my favorite program RubiTrack is another alternative for some serious ride analysis.

As the Garmin stores tons of data for every part of a ride software like RubiTrack, Garmin’s own Garmin Training Center or Ascent allow you to really dig into your routes, plotting details of ride down to the watt, rpm, heart beat or speed each moment of your ride and to plot those details against other data to see how you perform in different conditions.

RubiTrack for example makes it easy to track cadence vs. elevation or heart rate vs. speed, and it’s even possible to make a route “historical” to use as a baseline for fitness later on.

RubTrack (and the less flashy and slightly less powerful Ascent) takes this all a step further and displays routes overlaid on maps, automatically labels the starting places of rides, and also provides smart filtering of your events. (Find everything you did with a speed above 28mph or any ride that had more than 1000 feet of climbing, for example)


The Edge’s main drawback is its price. At around $600 for the model with heart rate monitor, cadence sensor and street maps it’s pricier than some bikes. But in a purely feature-by-feature comparison the Edge can’t be beat.

For Mac users Garmin’s quasi-support can be frustrating as well. Years ago the company promised full support for Mac users, but the mapping tool available to PC users for a decade still hasn’t been fully ported to the Mac, while programs like Garmin Training Center are anemic compared to the third party tools Ascent and RubiTrack.

Battery life on the Edge is good, the previous Edge models only ran for around four or five hours before needing a charge, but I’ve used the Edge 705 for basemile centuries and still had plenty of juice left over. However if you’re cycling off the grid for an extended period without power, the Edge is going to run out of gas before you do.

Future models of the Edge will likely pack more features (like a true electric compass, the current Edge gets directional data from GPS so the compass is only accurate when moving–not terribly handy when at a stoplight and trying to figure out which way to go) but the Garmin Edge 705 is the most sophisticated training and navigation device for cyclists ever.

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The elevation data should be taken with a grain of salt if the device doesn’t have a barometric altimeter. I work with engineering GPS on an almost daily basis, To get a true elevation you need to be stationary for about a minute. We have to set our antenna pole height every time we use it to make sure it measures correctly. You dont need the level of correctness that we do where I work, but if your moving quickly you may lose some data in the process.

Your GPS is going to collect a point every so often which will have position and elevation data and add it to the log your keeping. Besides features like the heart rate monitor, the best sensor and collection rate need to be looked at as well.

And we nearly didn’t use the E-Trex we took with us to Kona cause we just didn’t want to spend a morning (two mornings) reading the manual, but it’s a most and Garmin doesn’t make just a “GPS for your Bike” model with a mount. For some reason, the E-Trex mounts aren’t sized for modern bars, so we had to hack that.

Anyway, what I’m hearing and I think a struggle for growth beyond racer and bikes geeks is ease of use and reliability.

Wow - great post.  As a PowerTap user I’ve thought about jumping to an Edge 705.  It sounds like the top-level version of the 705 is really the only way to go.  Thanks!

It’s a great unit for the serious riders. I have an eTrex Legend C (no longer sold, but there are very similar versions.) Just having the ability to see the roads around me and where exactly I am is great. Many days I just go out for a 20 mile ride with no plan in mind, just riding until I want to come home, and then I can just see what roads are available without the ability to get lost. For club rides, I use bikely or mapmyride to create a gpx file, and upload that onto the gps. There’s been plenty of times when others are debating over which turn is coming up, and I can instantly find out the answer - it’s great.

The altimeter on a gps without a barometer works off trilaterization, which is accurate to about 200 feet, but fairly precise. Chances are, on 50+ mile ride the barometric pressure has changed and you aren’t updating it, so an altimeter would have the same amount of accuracy. If you really care so much about an accurate elevation, use mapping software that calculates the total elevation from the usgs data, since this is basically set in stone in the software and not at the mercy of satellites or the pressure which is always changing.

The Legend shows me anything I would need, such as speed, max speed, ave speed, moving average, an odometer, time of day, sunrise/sunset, distance or time to a point, etc. If you are considering a gps, just don’t go cheap and get a non-mapping version. Garmin sells many handhelds for just a few hundred bucks, and it’s well worth the investment to never get lost and have all the data at your fingertips.

Pretty nifty.  I can see where it might come in handy during a bike tour.

Too bad they don’t make a model (or attachment) that you can charge off a dynamo hub during the day.

Keep in mind that the E-Trex and the Edge are the same base software (with UI more tailored for cycling in the Edge, and with the ability to use accessories.) If you were using an E-trex, you were essentially using an Edge.

Depending on the E-Trex model though you get true compass.

@Chris - The edge 705 has a barometric altimeter.

Check the roads here in our [Kona Huggacast]( and the E-Trex mapped those for us. Old goat trails now abandoned roads and they showed up. That was impressive. What we did to save battery was just turn it on to wayfind and not the whole route. I will note we were frustrated that there wasn’t just a GPS for your bike because we’ve got Polars and iBikes and maybe don’t really want a featured-packed, complicated ass unit.

I just ordered an Edge 705 on Saturday and can’t wait for it to get here.  One of my concerns has been the battery life because of doing really long events.  The current newsletter on has a tip of using an Energizer Energi To Go Instant Cell Phone Charger to keep the Edge charged while riding.  The person that submitted the tip was using the 305 instead of the 705.  They thought it should also work for the 705.

@ultrarob - Any of the USB chargers will work. I use one that’s Griffin or someone’s little USB adapter. The nice thing about the chargers that do off AA batteries is that you can get AA batteries anywhere. (Keep in mind rechargable AA gives lower voltage than non-recharg, so YMMV.)

@BL “I will note we were frustrated that there wasn’t just a GPS for your bike because we’ve got Polars and iBikes and maybe don’t really want a featured-packed, complicated ass unit.”

Well, look at it the other way. You’ve got a GPS that replaces the complicated Polars and iBikes.

Also, if you don’t want complicated, turn on the unit when you start riding, turn it off when you’re done. Plug into your computer. That’s about as uncomplicated as you can get.

Yeah, I would say after a year of using a 705, it’s pretty uncomplicated. The initial setup requires reading a bit of the manual to establish what data you want shown on the device, but by just hitting “start” when you begin a ride and “Stop” when you get home, plugging it into your computer will give you nice detailed data dumps of everything about the ride.

Personally, I don’t plan out and map any rides (it’s a chore and on a mac throws lots of errors), I occasionally use the training modes to time intervals, but for the most part I just use the thing as a live computer and it’s definitely the best cycling computer I’ve ever used (it’s also handy in that it works without a speed sensor or anything so you can attach it to any bike you own or borrow (or even just throw it in the back of your jersey while you ride)).

I bought a 705 as soon as I got confirmation that Saris was going to make their wireless PowerTaps ANT+ compatible.  (I couldn’t get rid of my PT computer fast enough.)

The 705 is a major improvement over the 305, especially when it comes to usable maps.  When I was going to be doing some mountain biking last summer, I was even able to load topo maps instead of street maps.

My biggest complaint with Garmin has been their software.  (This goes for Training Center as well as Map Source.)  It’s always behind in necessary features and usability.  For example, Training Center still doesn’t show power numbers.

I really like the fact that I can quickly move my Garmin from bike to bike and easily capture my ride data.  I haven’t used the training features on the 705 yet, but I’ve got an interval workout planned for today and I’m going to check it out.

The majority of our “not going to spend vacation reading your damn manual” frustration was with the software. That and the mount, but again that was with the eTrex.

I’ve been riding with a Garmin that I bought for Geo caching. I love being able to meander through streets and neighborhoods that I’ve never visited in my own town, or Portland and always find my way back. It doesn’t have any bike specific software, but I’m not using it for fitness anyway. It also uses rechargable AA’s. If you’re caught out with dead batteries you can pick up replacements anywhere.

Note that the 705 does indeed feature a barometric altimeter.

It HAS a barometric altimeter and uses a gps unit to calibrate alt every ride so alt data are quite correct. The only draw back is that when You go out and ride without giving the Egde a time to calibrate alt You in did end up with unproven alt data. You must remember to live the unit open to the sky before ride to calibrate altimeter. It took about 3-5 minuts in my case. More on that and other Edge pros and cons on

@DL Byron

Garmin does make a bike mount (one that is larger than the standard, and fits most road bikes) for the eTrex. It works great with my eTex Vista HCX.

Here’s the one that I ordered.