GPS & Randonneuring – Part Deux

3 years ago, I wrote a post titled “GPS & Randonneuring.”  I have learned a lot in the last couple of years.  This is probably one of many updates, and I’ll continue to to update as I learn more information and technology evolves. 

GPS Units
There are limitations to the types of GPS units you can use.  While there are work arounds to just about any issue, my recommendation is to get a unit that has one of the following features: 1) batteries which can be changed or 2) a unit which can be charged AND still remain on.  The following is a list of Garmin units which meet either of the above criteria.

The difference between units with the “t” and those without is the “t” models come with preloaded maps.  I don’t recommend you buy these models.

Essentially, any handheld or cycling specific Garmin unit can be used.  While I would like to pretend price isn’t a factor, it is for many people, myself included.  The prices listed in the table above are “Sticker Price.”  Shop around.  I bought my Edge 800 off of ebay for $295 shipped – refurb, factory sealed, 1 yr warranty and another year warranty from my credit card.  I rode with a guy the other day who picked up a nice Edge 800, used from ebay for $250.  It is usually more cost efficient to download open source maps and purchase the HRM and speed/cadence separately from a place like Amazon.  All in, I was at $380 for GPS, maps, HRM “premium” strap and speed/cadence sensor.  The sticker price on that bundle is $650.

Some of these units seem to have frivolous features.  I don’t need a camera on my GPS unit or a QWERTY keyboard.  But, if these things are important to you for any reason and you already have the unit, you can still use it for cycling.

I’ll let you settle what weight and size are important to you.  We all have various opinions on it.  I will say, I used to ride with GPSMAP 60CSx.  I enjoy the compactness of the Edge 800.  Not a weight consideration, as I seemingly have an infinite number of ounces to lose around my waist, but I like how the Edge 800 sits nice and clean on my dashboard.


For units which utilize maps – all but the Edge 200, Edge 500 and eTREX 10 – DO NOT BUY THE MAPS FROM GARMIN.  This differs from the advice I gave 2 year ago, and you may do as you please with your money.  But my suggestion to anyone who doesn’t wipe their butt with greenbacks, DO NOT BUY MAPS FROM GARMIN.

My suggestion is to download OPEN SOURCE MAPS.  If you don’t trust the OPEN SOURCE MAPS go ahead lay down the cash for Garmin’s version.  I trust OPEN SOURCE MAPS, and programs like Ride With GPS (hereafter known as: RWGPS) use OPEN SOURCE MAPS.  Pick a map from list, I’m in the US and I use this set of maps by Dave.

Cheaper than Garmin, but still $25, RWGPS w/ send you a microSD card with maps already installed, so all you have to do is slip it into your GPS unit, select the maps and you are ready to go.  Below is my step by step process and notes on saving some moolah.

  1. Buy a microSD card.  I use Amazon a lot, and ended up spending $4 on a 4gb Kingston microSD card (which came with a SD card adapter).  You may want to check on the size limitation your GPS unit has for microSD cards.  And if you get too big, it will bog down the speed of your unit.  4GB, in my mind, is perfect.  You can get an entire map of the US, but it doesn’t affect speed noticeably.
  2. Download your maps.  This will be painfully slow (took about 2 hours for a 4GB download here at my work).  I suggest you use a bitTorrent downloader which not only speeds up your download, but keeps you from hogging too much bandwidth.  I use uTorrent.
  3. While your maps are downloading, you’ll need get the Garmin file structure onto your microSD card.  The easiest way to do this is insert your microSD card into your unit and turn it on.  Go into the settings and change it to write data to external memory rather than internal memory.  On the Edge 800 it is: Settings (little wrench usually in the lower right corner)->System->Data Recording->Record to->Memory Card.  I went back in changed it to internal memory right afterwards.
    Exit out and hit start, then hit the stop button.  Recording just this short period of time will have written the file structure onto your microSD card.  Power off the unit (anytime you insert the microSD or take it out, the unit should always be off) and remove the microSD card (if you will be transferring the maps to the unit using a card reader – recommended).
  4. Transferring maps by a card reader is recommended, but by no means necessary.  It is MUCH MUCH faster (15-20 mins compared to 3-4 hours for 4GB).  Simply open up the microSD card’s folder->garmin and place the .IMG file there.  Do NOT put it in the custom maps folder.  Safely remove the microSD from card reader.
  5. Insert the microSD into the unit and power it on.  You then have to go into the settings and select the map you want to use.  On the Edge 800, it is Settings->System->Map->Map Information Select Map.

Powering the Unit
Obviously, you want to start any long ride with the unit fully charged, or with fresh batteries.  Units which have replaceable batteries are, in my opinion, the easiest to manage.  With the GPSMap 60CSx I would buy cheapie batteries, throw 4 into my kit and when the current batteries died or were about to die, I would throw the old ones away and replace with 2 fresh batteries.  The downside is the GPS unit will split the track into two separate files, which requires stitching once you’re off the bike.  But navigation is not affected.  I use Basecamp for the stitching, but you can pick any of the options listed here.  I was able to get 15 hours or so of daytime use out of my 60CSx – a little less at night with the backlight.  That is the great advantage to a unit with replaceable batteries – it’s cheap and easy.

If you buy an Edge Model, or you just don’t want to deal with the batteries, there are options to add juice to your unit.  The simplest is to buy a battery pack.  Garmin sells a version, which is way more than anyone needs to spend.  Gomadic makes a unit (AAx4) and so does Energizer (batteries x2)According to a post on this forum, not all USB cables are the same, so while it is common to see the “younger” Edge models turn off while charging, simply selecting a different cable can fix the problem.  Peter White says the same thing on his E-Werk page:

So, if you find that your GPS won’t run while charging from the E-WERK, try using the standard USB cable, and then the standard USB to Micro or Mini (whichever your device requires) cable provided with the E-WERK.

The final option is to power the unit with a dynamo hub.  Since there are limitations on the amount of volts and amps, you need to purchase either an E-Werk (Peter White is sole importer in the US, but you can always buy from overseas) or PedalPower +.  The newest is Sinewave Cycles, which I will most likely purchase.  Not only do these thing-a-ma-jigs adjust out put voltage and amps, but they also convert the AC power from the dynamo and convert to DC.  Since Voltage drops at low speeds, it is wise to use these gizmos to charge a battery, and then use the batteries to charge your unit.

As you can see when looking at a battery pack for $15-$20 vs $300-$350 and more “stuff” to carry.  My headlamp takes AA batteries, so if my battery pack does as well, at least there is some standardization.

Planning Routes
I use to advocate the use of Garmin’s BaseCamp or whatever software Garmin had on offer.  Now, my eyes have been opened to the world of RWGPS.  And many suggest BikeRouteToaster as well.  Planning routes is simple, and even bicycle specific.  And they’ll export the appropriate file for your GPS unit (if you want to write directly to the unit, you need pay for “premium”).  I select the appropriate file (TCX for the edge 800) and download to my desktop of where ever I want to temporarily save it.  When looking at a route on RWGPS, you’ll notice on the right hand side a column, and you want to click on the “export” tab.  They even have individualized directions for each cycling specific unit (Edge line of units).

CaptureOnce your route is downloaded, you then open up the file structure on for your microSD through either your GPS unit or a card reader (GPS unit works fine in this case).  The files is Garmin->Newfile.  You drop the GPX or TCX file into the “Newfile” folder.  On the “home” screen of the unit, you look for courses and select the one you want.  One last step, after you select the route you want to follow, before you hit that big green “GO!” button, I select the small wrench (“settings”).  I turn on the “Turn Guidance,” off for the “Virtual Partner” and off for the “Off Course Warnings.”

Doing this should give you turn-by-turn directions.  Your unit will beep as you get 40-50′ from a turn.  Then it will make a little louder sound as you are just about at the turn and the screen will change to a close in map to show you the navigation through the turn.  As many RBA’s will put on their website, the official cue sheet is handed out right before the ride.  If the RBA is kind of enough to draw the course up in RWGPS our lives are certainly made easier.  But, you should always verify with the cue sheet.  I like to email the RBA a few days before and get an electronic copy, I can then match against my RWGPS map and export.  I then ask the RBA at registration if the course has changed, and usually they almost always reply, “no.”  I then have a high degree of confidence, not complete trust, that the GPS is correct.

I like to use Strava to download my rides.  It’s easy to use, it gives me the data I want and best of all, free.  Those paying for a premium membership at RWGPS can download there and Garmin Connect is also a popular one.  If you have multiple files, you’ll need to “stitch” them together using Garmin’s BaseCamp or another one of these options.


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