Dynamo Hub

[trebor]

Since the SPOT Connect thread started to get off topic I brought my ideas over here to a new thread.

So, I'm testing a dynamo hub right now and am really liking it. The resistance under load of a 1W led lamp is imperceptible. I do wonder about long term durability however, and plan on bringing a back up light for all my overnight adventures; a simple 90 lumen AAA battery headlamp.

Excluding for a moment the disadvantage of a hub failure leaving you "in the dark", I've been really mulling this over and finding it a win-win. But until I’m done testing, it's just hypothetical.

Here is my plan. Testing over the next 3-4 months with daily commuting and at least one 300 mile race and a couple of overnight trips. Light straight out of the dynamo are easy to use and bright. With the addition of a device like a Dahon Reecharger I can run lots of gadgets: http://www.dahon.com/news/releases/2009/08/dahon-brings-green-power-every-bike

The Reecharge comes in at 90 grams and has a 1600mah battery.

I can charge the battery during the day and then recharge my devices at night when i go to sleep. I can also "top off" items a the same time the Reecharger itself is charging to keep GPS, phone, or say, USB rechargeable light ready and fully charged. The Minewt line of lights from NR and some Cygo lights are USB chargeable and in theory, can always be ready for use.

If anyone cares to know my results I can update my findings as I learn. It is a little expensive to "test" but after doing the math on the number of batteries I might use on the Divide, this may actually end up being cheaper. And then I can continue to use it after for more adventures.

If anyone has gone through these efforts already, please share your results.

Rob

[the_mc5]

i for one look forward to your observations!

which hub and light are you running?

[trebor]

Shimano DH 3D72 hub laced to a 29er rim

Planet Bike Blaze light

[bmike-vt]

Have you considered the EWERK? Might be more $$$, but appears to offer more variations for device charging.

I'm currently running a SON with eDeluxe on my rando rig. Couldn't be happier, especially with the newer led lights, as I came from running dual dyno halogens, and would have to turn one off when climbing. 

[trebor]

i think i considered every option i could find. in the end, the budget was the deciding factor. I have a friend here in FLA that road tours and he uses EWERK. he indicated he really liked it.

[joeydurango]

I have a Shimano Alfine dynamo hub with a Busch & Muller LED light on my commuter and love it.  I've been seriously considering trying the same setup on my MTB, especially for multi-day events where battery capacity (and extra-battery-carrying-capacity) are limited.  From my experience on the road and bike path, at least, this setup seems like a plenty-bright option.  The light begins putting out serious lumens at very low speeds, which is a necessity for MTB (technical climbing, etc.).  Anyone have first-hand experience with this particular setup?

In any case, I'm very interested in what you find out, trebor.  Keep us all posted!

[Area45]

I've been going back and forth on this myself. I currently use a SON 20 with the Supernova E3 on my rando bike. It's completely spoiled me.

My thoughts are to build up a front wheel with the SON 28 and, like you, I'm planning to do all of my TD training with it and then deciding whether it's worth the extra weight or not. I've also looked into the pedal power unit to charge the GPS and anything else that might need charging. I think it could allow for much more night riding depending on the terrain.

 I'm glad I'm not the only one considering this.  I was starting to think I was crazy.

[Aslan]

You are not crazy.  That is a brilliant idea.  The maps and GPS on the Iphone / Droid are now quite robust.  Add the ability to charge up other electronics and lights and you have a real weight saver in terms of batteries and gadgets.  I will be curious to hear the results of your testing.

[DenisVTT]

Yes, keep me posted as well.

What's the total cost (approximately) to build a 29er wheel with a dynamo hub when you don't have the wheel building skills to build it yourself?

[trebor]

This hub cost me around $100. add that to the cost of spokes, rim and shop labor.

[trebor]

some feedback so far....

Ran the Reecharge unit on a 30 mile singletrack ride yesterday. I used it on a Delorme GPS.

The nice thing about Delorme that i think may not work with some Garmin models is it doesn't switch to "recharge" mode when you plug in the USB. It instead, draws power from the USB and stops drawing from the AA batteries. The AA batteries were 100% in the GPS and the Reecharge was at about 50% capacity at the start of the ride. After riding for 3 hours, the batteries in the GPS were still 100% (which normally when using NiMH rechargables after 3 hours would be around 50-60%) and the Reecharge was still at 50%.

I then used my Reecharge disconnected from the dynamo on the way home to charge my cell phone. My cell was less than 15% (according the battery app) and was charge to about 50% before the Reecharge was exhausted.

I noticed no perceptible drag while riding from the dynamo.

I like it so far.

I bit of talk in the 11 TD thread about over current/over voltage issues on long fast descents came up. I am sending and email to Dahon to see if they can tell me about how their device handles such concerns. Being from Florida, i can't actually test this.....

[trebor]

Yet more info...

Regarding over-voltage concerns on both the light and Reecharge, I contacted each company.

Planet Bike said that there are no concerns with their light from an over-voltage perspective. Nice! They also said that since current draw on their light was so low, you could actually run two in parallel on a 3W hub for 2x the light. Nice again!

Biologic, retailer of the Reecharge, responded that there is an over-voltage concern. Their testing was safe up to 25kpm on  20" wheels. I did a little converting to a 29er and MPH and came up with about 24mph. So I can run the system on flats and shallow grade downhills without issue. Longer steep descents in excess of this speed can be a problem.

To prevent any issue, I'm going to install a switch in line and mount up on the bars for quick access - so i don't have to remember to unplug the wires from the hub.

(I have to admit - I'm nerdin' out over this.........)

[DoctorRad]

You're running the Planet Bike Blaze light from a dynamo? I thought that was a battery light?

Also, if you're running two LED lights from a dynamo, they should be in series, not parallel. Dynamos are current sources, and LEDs are current devices. Useful reading here: http://www.pilom.com/BicycleElectronics/DynamoCircuits.htm

[Area45]

I got my SON 28 hub built up yesterday. I have it connected to a Supernova E3 Triple. I took it out for a ride today and did 43 miles with about 4000 feet of climbing. I kept the light on for all of the climbing and some of the flats. I didn't notice any drag at all. I built the wheel using Stan's Arch rims and WTB Nano raptor tires. Compared to the stock wheel that I was running, the front wheel, with the larger dyno hub is only 500 grams more! I also have the Pedal Power unit which will allow me to power the GPS, but I ordered the wrong connector so I haven't been able to try that out yet.

[trebor]

That looks great!

I'm still trucking along with my testing without a hitch. I'm digging in the fact that I never think about batteries!!

[DoctorRad]

Where's the Pedal Power unit from, and what cost? Will be interested to know how you find it when you can use it.

[Area45]

I got it from my lbs, but they get it from Peter White cycles. I got the iPhone version because it comes with the piggyback connectors already installed. The cost is $136.

http://peterwhitecycles.com/pedalpowerplus.asp

[bmike-vt]

I got my SON 28 hub built up yesterday. I have it connected to a Supernova E3 Triple. I took it out for a ride today and did 43 miles with about 4000 feet of climbing. I kept the light on for all of the climbing and some of the flats. I didn't notice any drag at all. I built the wheel using Stan's Arch rims and WTB Nano raptor tires. Compared to the stock wheel that I was running, the front wheel, with the larger dyno hub is only 500 grams more! I also have the Pedal Power unit which will allow me to power the GPS, but I ordered the wrong connector so I haven't been able to try that out yet.

Sweet looking setup!
This is what I'm looking at for TD012 or 013.

[Area45]

Just did a 3-day bikepacking trip with this setup over the weekend. I used the pedal power to keep a Brunton Soloist battery pack charged up all weekend. This proved useful when my friends GPS ran out of juice. We just moved the battery pack over to his bike and he was able to navigate the rest of the weekend. We also ended up riding at night on dirt roads. I stayed towards the back and was able to light the way for everyone with the huge light. Pretty awesome. We rode across streams, encountered mud and I never had a problem with the connectors on the hub. I'm convinced it's worth the weight/cost. I think I may have converted a couple more riders too!

[trebor]

I ran my set up in Pisgah over the weekend. Started off Friday night in the dark and rain. I was able to keep my cell phone charged, my Cygolite USB chargable light topped off and run my GPS off the system instead of eating through batteries.

I'm digging this system!!