The Fahrradzukunft magazine published a highly interesting review about dynohub chargers conducted by dynohub manufacturer Schmidt and others. The article was published in German language and unfortunately does not cover my Jawetec charger due to its unavailability. However, there are several interesting devices including the pedalpower+ stuff (check my link bar for more information on it!).
Update: the Fahrradzukunft magazine recently published part II of the USB charger article with some more very interesting devices and updates.

A short note on this blog: Most likely I will continue writing this blog at slow rate in German language. Xtracycle released several very interesting new addons and pannier kits and things are going on, but it is not such a big hype anymore. I believe it is worth of talking about in our native language, although big dummy cargo bicycles are still not a big issue here. At least, people realize the concept is useful, and I still love its great versatility and riding style.

I have been successfully using the jawetec bikecharger in combination with several devices for several trips at my bicycle, and I really like it. Today I received the information Jawetec’s web page is no longer available. Currently I have no clue whether their bike charger is still available somewhere. Since this great little gadget has been mentioned many times within this blog, please be aware that any links to the Jawetec page from this blog have become obsolete. I do not know, what happened to the company. In my opinion the Jawetec charger is one of the most useful accessories with bicycles and dynohubs, and I very much regret if production is stopped. There are similar products out there, but those are more expensive than the lightweighted, sophisticated, reliable and small Jawetec bike charger.

By the way, in spite of the fact that this blog has not seen updates for quite a long time, the Big Dummy is in happy use. 2009 milage compares to 2008′s. Snafu Knob Job tires, however, show far better durability than the Fat Franks used before. Apart from that, the Token bottom bracket again shows up some outer slackness, so I will probably use ordinary Shimano square tapered or whatever in the future.

Today was my first test ride for the new power supply device chain: new dynohub SON 20R, JaWeTec Bikecharger, SwissBatteries PowerTank M, Garmin Oregon GPS without internal batteries, Schmidt Edelux lights playing all together. I did some short slope of probably 45km with some 1300m of elevation. Most of the uphills were too slow to keep the bikecharger charging the Powertanks internal battery, so I switched it off at uphills and let the Powertank drive the GPS on its own. At first image those two Powertank LEDs are visible. A red one indicating charging state and a blue one indicating some device at USB out consuming power.

With such short ride I could not enforce any power outage and I could not determine whether the GPS would empty the Powertank quicker than it could be recharged by the bikecharger. No problems today. The Garmin GPS ran continuously without internal batteries, performing routing, showing maps, trip computer and several other jobs permanently. No power saving mode, but no backlight, though.

Charging of the Powertank starts at less than 10km/h with the SON 20R dynohub. As soon as speed goes further down, one should consider switching off the bikecharger to protect the Powertank from those remaining slow pulses at DC out of the bikecharger no longer being able to provide constant voltage from dynohub out.

There is one more interesting experience: with the SON 20R there is no need to switch on the lights when reaching speed of 50km/h to protect the bikecharger from dynohub overvoltage. Actually the charger would switch off itself automatically for that reason. I had to take care about this when using the stronger SON 28S dynohub.
On the other hand, I found out, as soon as switching on the lights, there is not enough power to charge the powertank, no matter how fast I am riding. With my previous installation it looked as like there was enough power left to charge the GPS even when lights would shine, but there definitely is not. The Powertanks red LED will not even flash slowly with lights switched on. So that was not a very good idea, anyway. Something that I will no longer pay any attention to.

Finally some words on installation and weight: the whole collection of USB devices and cables including GPS but without dynohub and lights makes up 342g. See third image. Installation looks some kind of messy at the moment, but everything will be protected by some small bag mounted at top tube. At final stage there will by two wires from the top tube bag to handlebar and the GPS at the handlebar. Should look quite clean. Need to get appropriate bag.

The image shows my new ensemble of USB gadgets, the mobile power supply chain I will be using for further touring. Located uppermost is the JaWeTec bikecharger, that I had used formerly. See my previous posts about this topic. The bikecharger is connected to the dynohub und will create constant DC of 5V at its USB-out which is wired to DC-in of the new lightweighted SwissBatteries PowerTank M. This basically is some sort of optimized rechargable LiPo battery pack with some electronic circuit. The PowerTank will on the other hand permanently feed the Garmin GPS (without internal batteries) at its USB-out. This works, but I need to test whether the bikecharger will be able to keep up enough power level to ensure continuous operation of the GPS in the long run.

Finally I received missing Sapim Force spokes of length 254mm in black colour and built the new Big Dummy front wheel with lightweighted SON 20R dynohub and strong Spank Subrosa rim in chocolate colour. This time I took some pictures showing the building process which should pretty much follow Sheldon Browns guidelines with 3 crossings. Leading spokes run at inside at outermost crossing to maintain better tension at trailing spokes when braking hard with disk brakes.
The resulting wheel should be very strong. It has got 1197g of weight (including rim tape, without quickrelease axle). That appears quite ok for a durable disk brake dynohub wheel. The new front wheel will replace my current SON 28 / Spank Subrosa front wheel at the Big Dummy. The latter one will be installed at our winter MTB where it will replace an older Shimano dynohub wheel, making it easier to juggle lighting equipment between those cycles just in case. Also I can finally install my Shimano XT centerlock front disk rotor to the Big Dummy, replacing a cheap noname 6 bolt rotor. And last but not least, it will shave off another 200g of weight without introducing any compromise.

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Here it is. Measured 392g of weight without axle. Note there is some protective plastic coating around the hub making it less shiny than it actually is. Plastic will be removed after wheelbuilding.
Unfortunately silver spokes were supplied instead of black, so I will have to wait some more days before being able to build and ride the new wheel.

Bicycle Holder Installation

Within the last weeks I have been gathering some practice with my new Garmin GPS, an Oregon 400t model. It was attached to my MTB, the Big Dummy, a motorcycle and a scooter. Finally I installed two bicycle holders, one at the Big Dummy and one at the scooter. I will need to buy at least two more of them. The Garmin bicycle holder for Oregon and Colorado models is simple and cheap, but it is not ready for hard bumps and impacts, probably dropping the device incidentially. Thus I had to feed in some layers of soft rubber tubing to prevent heavy shattering of device. While this was possible in an easy and efficient way at the scooter due to its thin handle bar stay providing space for a thick rubber layer, at the Big Dummy I had to keep my anti vibration layer quite thin due to thick 31.8mm handlebar. See images to compare both mounts. Nevertheless, I am hoping there is enough rubber to make it absorb hard shaking and keep device in place.
There are several GPS mounting systems available as like Bikertech customized, Ram Mounts, Touratech and probably lots more, most of them fairly well addressing the oscillation issue, but in my opinion they are way too big and heavy for my small vehicles, also quite expensive.

Power Source

Lengthy trips require some thoughts about GPS power supply. Batteries may be sufficient for one or at most two days of continuous use. Some battery charger will be needed most likely, since the Garmin would never recharge its batteries inside when plugged to some USB power supply.
Trying to avoid another battery charger in my baggage, I connected the Garmin to my hub dynamo via the JaweTec Bikecharger mentioned previously here. Basically this works, but it is far from being a perfect solution:

• With the SON 28 dynamo a continuous speed of at least 10km/h is required to provide enough power for the device. As soon as riding slower the GPS will start beeping and switch to battery if possible or just shut down.
• The charger is not recognized as a simple power supply. By default the GPS goes to mass storage mode when the charger is switched on. To prevent this, the devices USB interface needs to be set to Garmin Spanner mode, which means, for every short power outage one needs to confirm switching to GPS mode instead of mass storage mode at some popup window coming up with a nasty beep, again and again. Thats sort of cumbersome.

For the motorcycles there is no problem about power supply since it can simply be wired and plugged to the battery via some modified USB converter taken from my previous navigation device. Thus I can run it without any battery inside which is strongly recommended with offroad usage. For the Big Dummy I am still in search for a better solution. I may probably connect a special battery charger to the JaweTec charger and keep a pair of fresh batteries there, but actually I do not really like this, since it requires taking along too many small devices and batteries. I may probably just get a small and lightweighted charger and recharge batteries every night, leaving the JaweTec charger at home.
Another feasible solution would be the dynohub driven Zzing USB charger providing internal battery buffering (unlike the JaWeTec charger) for devices not being capable of USB charging. This way the Oregon GPS could be used totally without its batteries (keeping it lightweighted with better protection against bumps and vibration). However, the Zzing charger is quite big.
As to some readers comment the Australian company Pedalpower+ provides DC hub generators and several more interesting mobile power supplies for bicycle usage.
I finally decided to stick with my reliable JaWeTec charger and put some USB chargeable power buffer, called PowerTank by SwissBatteries in between the charger and the Garmin Oregon. I will give it a try and report about it.

Within the last days, the brandnew Schmidt dynamo 20R came out as centerlock version.

Check manufacturer Schmidts homepage for details. I hope I will receive this item within the next few weeks. It will replace my SON28 disk hub in the Big Dummy, shaving 200g of weight off the latter. Also, I will finally be able to install my Shimano XT 2008 disk rotor with it. Currently I need to use some 6-bolt replacement rotor instead. Maybe, probably, this could have an impact on the fork oscillation issue mentioned previously. I hope so, but I do not know at all.

Late addendum: In the manufacturers installation document there is a clear statement against using this hub dynamo together with disk brake in tandems or cargo bicycles with front wheel(s) sized bigger than 20″. I have not been aware of that severe restriction until I found the mentioned document to be released, so I would like to point it out.

Today the installation of Medion MD96050 (PNA465) navigation device was finished and tested. The Medion PNA is connected to the JaWeTec USB charger (see previous post) and powered through the dynamo hub (6V/3W). It works well. Charging starts at riding speed of 7 km/h. When lights are switched on additionally, it starts charging at 12 km/h. USB charger can be switched off easily. The PNA together with the USB charger can quickly be removed by unplugging power supply cable.

When testing the whole arrangement rolling up and down our street an hour ago, a bicycle traveller with lots of baggage and a bob trailer came along and we started talking about bicycles. He turned out to be the owner of the well known bakfiets cargobike distributor Beer Transport Fietsen in Den Haag. Due to my previous web research concerning big dummy related stuff I knew the shop. It was very nice to meet you and your family here. Have a good trip and lots of sunny rides!

Today I received the JaWeTec USB charger for dynamo hubs as like SON or Shimano DH-3D71 or Alfine or similar. This is a small box with an ordinary USB type A connector which provides 5V of direct current and 500mA, which should be sufficient to feed any USB charged devices according to USB specification. It is protected against overvoltage up to 50km/h as to manufacturers documentation and may switch off automatically at extreme voltage or heat. The little box has got 50g in weight approximately and can easily be removed from bicycle by unplugging its connector in the dynamo cable. The box unfortunately is not water resistant. I will attach it at downside of my Medion PNA and put the complete unit into some transparent plastic bag.


The chargers power supply cables had to be soldered to the original cables of my edelux headlight. I opened the protective coating around the dynamo connectors, made a soldering joint for each of the two wires and put new shrink hose around each connector. The charger cable runs along the speedo cable up to the handlebar where it can be connected to the box which will be installed together with the navigation device is mounted.

Update: unfortunately the Jawetec charger is no longer available as to my knowledge.

Using some pocket navigation or GPS device for big dummy touring may seem a good idea. For those, using dynamo hubs, JaWeTec in Germany provides some interesting solution for charging USB devices as like PNAs, music players and whatever. A similar device is available at Stollberg Elektrotechnik in Germany. For real outdoor freaks, there even is some 12V solar charging device available (Switzerland), and there is another German supplier with lots of useful navigation equipment and accessories for bicycling usage.

Late addendum: Zzing provide some USB dynohub charger with internal batterie buffering. It works similar to the Jawetec charger but will keep up delivering power even when cycle stops or goes uphill slowly.
Another very flexible solution could be a combination of a small unbuffered dynohub-USB charger (see above) with the SwissBatteries PowerTank which is some sort of mobile power buffer rechargeable in several ways and providing USB out.
Also I would like to mention Pedalpower+, an Australian supplier with several very interesting dynohub solutions, even providing DC hub generators.
And here is another one I recently found: Busch & Müller E-Werk is a brand new universal dynohub charger, apparently without an internal battery buffering, similar to the Jawetec charger.

The new headlight was installed two days ago. It is small and looks cute with its black aluminium jacket. When using the built in twilight sensor, it will be engaged most of the time, since it only switches off when being exposed to sunlight, so this should be slightly adjusted by manufacturer. Nevertheless, it can be switched off manually. There is a yellow-greenish gleam in the LED beam when turned on, which reminds me at unreal tournaments plasma gun. This sort of light colour may improve sight at night, according to manufacturer.

Today my dealer and parts dispatcher notified me about availability of the brand new Schmidt / B&M Edelux headlight. I will receive my black edelux version within the next days. It will replace the Inoled 20+ on the Big Dummy.
For those interested in up-to-date premium bicycle lighting technics with dynamo hubs I would really like to point out the qualified and rapid service at Komponentix with lots of valuable information on their page.