MotionX GPS app, ReeCharge Power Pack, Dynamo hub

For my recent trip to the Middle East, I ended up leaving the Garmin 705 at home. Even though it was indispensable in guiding me to small roads in Europe and New Zealand, there are no maps for it for Syria, Jordan and Egypt. And there was little point in collecting data on distances, speed, elevation gain, etc., because, well, I don’t care. I was, however, craving street maps of the urban areas I was visiting. And while I always take along or find paper maps, having a GPS as backup to confirm that you are where you think you are on a paper map is convenient.

I had had the MotionX app for the iPhone for some time, but I was still astonished when I was able to use it to download clear and detailed maps of the region.  I loaded all of these at varying levels of resolution (Zoom setting from 6 to 15, for those of you who use the app) to store on the phone. That way, I would not need to be connected to the network to look at the maps.  All the maps together took up a few gigs. The built in GPS was then able to project my location on the maps, and do all of the things one normally expects a GPS to do. It worked brilliantly: the maps showed even alleyways and dirt roads. As a bonus — though it didn’t seem so initially — the place names at most resolutions are in Arabic. This made it so I could show the phone to locals to confirm my directions and route. Even in that mobile-jaded context, where phones are routinely used for everything and far more than ever occurs to me, several people seemed surprised that such things could be on a phone.

Zoomed down to the street level


A fairly macroscopic resolution


The route that I took into Cairo
the first time I was there, before the revolution started

To keep the phone charged, I was using the Biologic ReeCharge Power Pack connected to a generator hub.  The converter is zip tied to the fork leg. It has leads going to the hub and a plug in connector for the power pack itself, wrapped around the headtube.

After a half day of pedaling the charge pack was full, and I could then connect it to my phone. One full power pack could recharge the phone fully about three times.

It is possible to mount the iPhone on the bars and charge it as needed from the recharge pack. That, I suppose, would allow you to observe your location in real time. I don’t use the GPS this way, as I prefer to have a map memorized or on paper which I follow until I get stymied. At that point I’ll turn on the GPS to figure out where I am. Just a luddite habit, I suppose.

The Shimano hub I took is designed for a 20″ wheel, for, say, folding bikes or recumbents. It has a bit less drag than the unit designed for bigger wheels. The assumption is that the 20″ wheel version will be turning more quickly, so does not need to put out as much power at a given rpm. The upshot is that, with a 26″ wheel build, one must go faster to get the same output from the hub that would be achieved in a smaller wheel. All of these measures are fairly conservative, since dyno hubs are designed for slow-ish moving commuter bicycles. I was getting a full green light in the charge pack even at modest climbing speeds.  The wheel was built by Rob English.

Everything worked flawlessly.  Of course, the front wheel is now gone along wit the rest of the bike. I’m pretty sure I’ll replace it with the same at some point.

6 thoughts on “MotionX GPS app, ReeCharge Power Pack, Dynamo hub

  1. I’m setting up a recumbent for a long tour and had considered taking along a portable solar panel (I will have a laptop, cell, ipod, and digital audio recorder). However, this is looking to be too impractical. I realize I won’t be able to keep all these devices going with the ReeCharge (I will be in the United States, making many stops and hunkering down at many coffee shops, besides), but it seems like a worthy investment, seeing as how I’ll be doing all that pedaling anyway. I am wondering about the hub dynamo, though–they seem to have different volt/watt ratings and I frankly don’t know what this means or what will work best with the ReeCharge. Any advice?

  2. Hey Julian,

    I’m certainly no expert on the hub dynamo stuff, but my impression is that the Reecharge will play well enough with all of ones made by, say, Schmidt or Shimano. Any hub that meets that German standard for output (and virtually all do) will trickle power appropriately.

    As mentioned above, the particular hub that I was using is designed for 20″ wheels. In the Shimano catalog it is a DH-3D72 Dynamo 32h Centerlock Front Hub. I was readily charging the battery pack at 10mph on a 26″ wheel build, so you’d have no problem with the faster turning recumbent wheel.

    Hubs will vary, of course, in terms of build quality and in terms of resistance. Though it’s not up to date with the latest hub offerings, take a look at this article:

    I’m also intrigued by the new Velo Orange generator hub that can be switched off, i.e., no additional resistance over a standard hub, when not in use:

    Whichever hub you get, note that the Reecharge unit comes with all the wires and connectors that you need.

    Hope that helps a bit, and thanks for looking at my blog.


  3. Thanks for the write-up. After reading a few negative reviews on the Dahon online store, I was happy to come across this –it’s tipped me in favour of buying one for my upcoming trip. Happy travels.


  4. Hello, Joe. I really didn’t know if a better past for this question (and couldn’t find an email address), so I opted for this one.
    I’ve been curious for some time why you never became more enamored of a high dynamo, given your propensity for of the beaten path touring.
    Do you trend to primarily rely upon a headlamp, never minded using the batteries or something else entirely?

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