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-   -   WHAT DYNOHUB??? (my application) (https://www.bikeforums.net/commuting/342629-what-dynohub-my-application.html)

JOHN J 09-17-07 11:23 AM

Thanks for all the replies,

Well I ordered a schmidt in the Anodized Black , Like Dan Blanton the saltwater Fly fishing Guru says "Buy it once cry once"

The wheel is a velocity Dyad, Black with a machined wall, 36 spoke.

I went with a Inoled 20+ LED and a Dyno powered tail light.

Again thanks for all the help.

"John"

whatsmyname 09-17-07 01:30 PM

Hey, make sure to update us on how you get on with it!

n4zou 09-17-07 02:58 PM


Originally Posted by n4zou (Post 5263624)
I use an MUP after dark and found most lights much too narrow as well. I was also going broke buying AA batteries! I purchased a cheap Schwinn dynamo lighting kit but burned out the taillight after only 2 hours so I had to revert to my LED Mag-Lite flashlight. I like it as it allows me to adjust the pattern between wide and narrow as necessary. I consequently converted the Mag-Lite flashlight into a dynamo-powered headlight. Here is the link on how I did it.

http://www.bikeforums.net/showthread.php?t=339965

The above link shows the test and reliability setup. I've ordered better components such as 1n5818 diodes instead of the bridge diode matrix from Radio Shack. The circuit shown should work fine for dynamo hubs as well, as they will be much better than my cheap ($7.20) bottle dynamo kit!

http://i143.photobucket.com/albums/r...amocircuit.jpg

The new circuit will be imbedded in epoxy instead of the exposed "birds nest" setup strapped to the rack. I have over 100 miles on the test setup without problems with the flashlight and test board.

I was riding through the local college campus via the MUP and this guy noticed the circuit board connected to my bottle dynamo and wanted to know all about it. I described the LM-317 regulator circuit shown in this thread. He tells me he's working an electrical degree and said I didn't need the regulator or the capacitor. All I needed were two NiMH rechargeable batteries across the bridge rectifier to regulate both the voltage and current for my 2 AA flashlight and 5,000 MCD taillight. When I got home I tested his design and he was correct! I subsequently tried a 3-battery setup with a 3 battery LED light and the 3 batteries regulated the voltage and current perfectly as well. I subsequently have built the circuit and have been testing it. It's great! I did 30 miles and my lights never went out at any stops and I even walked my bike up the very steep hill home with both the flashlight and taillight working fine. I've even ridden around with the switch open recharging the batteries as I ride. At no time can the dynamo put more than 500mA across them or exceed the voltage required for recharging them. I tested the current for the LED's and found that he was correct. The LED's take what they need and the batteries sink the excess current for recharging them. It's doesn't get any better than this!
I've found that the dynamo starts recharging the batteries at 8 MPH with the LED's turned on. With dead batteries the LED's will illuminate at 5 MPH. I started a test run with dead batteries just to make sure the LED's would still work with discharged batteries and they work exactly the same as the LM317 regulator circuit with no batteries.
Here is the circuit and short information he made for me.
http://i143.photobucket.com/albums/r...mo-battery.jpg

randya 09-17-07 03:17 PM

I just buy used Union bottle sidewall dynos at $10 to $25 per set, that's a lot of lights for what you're planning on spending. FWIW, the one shimano dyno hub I have (an older 2.4W model) doesn't put out a whole hell of a lot of light compared to the Union bottles. The older Union lamps have really good focused beam lamps, too.

Geekage 09-19-07 12:22 AM

The problem with using any kind of rechargeable battery as a voltage regulator is that you can vercharge and destroy the battery, so you'd probably want some sort of regulator in there anyway. It would be nice to actually fit a battery charge circuit in there, say some off-the-shelf Maxim chip, but that complicates it a bit.

Also, yeah, regular NiMH batteries lose something like 1% of their charge every day, but there are newer "hybrid" NiMH batteries that, while being rated as much lower power, lose only 15% of their charge annually. I've bought some sets for my occasionally-used flashlights and headlight.

spokenword 09-19-07 10:06 AM

Bike Quarterly did a pretty thorough comparison of generator hub resistance so if you want numbers to back up the anecdotes, check it out.

Basically with an average speed of ~18 mph, with one light switched on, the Shimano 3N71 takes off maybe 8 watts of power from your pedal stroke because of drag. The Schmidt is a little more than 6. With the lights switched off, a Schmidt adds only 1 watt of drag, and the Shimano adds 2. So, in real terms, it's not a lot of difference between the two, but your mind can excacerbate the differenece if you're tired and cranky, so perhaps it's worthwhile to spend money to know that you've bought the best.

I have a Schmidt dynohub on my brevet/commuter bike and have never regretted it.

bmike 09-19-07 10:38 AM

Getting late to the conversation.

On my Bakfiets I have a bottle generator and a D'Lumotech. It comes up to power at low speeds and has worked great.

On my IF rando bike I use a Schmidt with dual E6s. Lots of light on the road and I only need worry about spare bulbs.

I have debated going to a D'Lumotech and E6 on the rando bike, as the D'Lumotech is and LED and theoretically will run forever, and it comes on to full brightness at low speeds, but I haven't tested it yet. I've done some homebrew research on wiring some of the new Luxeons to the dyno but haven't tried them yet either.

andrelam 10-08-07 08:30 AM


Originally Posted by andrelam (Post 5250869)
I just put down my money at Peter's shop for a Shimano hub (with one of his hand built wheels), and the Delumitec Oval Plus Senso light, total it is under $300. This is more than I was planning to spend. I should have it in about 2 weeks. <SNIP> I'll report back when I have everything installed.
André

I finally got my wheel and light in last Friday and installed it immediately that night. The wheel is a 32 spoke Velocity Dyad black with machines sides. I only ride on streets with 700Cx35 this wheel should be plenty strong.

The light came with the standard mounting hardware that works great on my Garry Fisher Nirvanna as I can use the same mounting bolt that also holds the front SKS fender on. Since I have a handlebar bag there is no easy place to put the front reflector (not that I count on it helping much), but that is built into the light as well. After much reading on Peter's web site I decided I would go with the LED light. I like the fact that the "bulb" should last a very very long time, and they are very energy efficient so startup speed is very low. I also ride mostly in suburban areas so the little bit of scatter makes me more visable to cars at the cost of a little bit of visability.

Installation was a snap. I did notice the resistance as the wheels spins without anything attached. This is ofcourse the result of passing through the magnetic field of the generator. Once I transferred the tire (Bontrager Select Invert) from my OEM wheel (Bontrager Camino) and I spun the wheel it was much smoother. I then tested the OEM wheel and noticed that it felt nearly as notchy as the Shimano hub. I guess they used pretty cheap bearings even on a mid-priced bike. The instructions on the shimano hub are plenty clear on what side to have the electrical connector and there is also an arrow clearly on the hub. The light comes with wires that are plenty long, I took the connector piece off the hub. Attached the right to the arch of the front suspension fork. I ran the wires down the side and atached them with some tie wraps. I left a little length of wire and stripped the wires to the right length. The connector had the holes where the wires enter filled with di-electric grease to keep moisture out. Snap the cover over the connector and snap it onto the hub. All every simple and everything worked right away.

I did have to get a new inner tube as the new wheel is designed for Presta valve inner tubes. No biggie. I've read that the Presta tubes should hold the air a bit better so that is no loss. Now I just need to get the little $2.00 adapter that Peter sells so that I can also put a Presta tube in the rear so that they match.

I took the bike out for a ride around the neighborhood and found a dark section so I could adjust the aim of the light. Nice bright beam. I have no problems seeing the road at 15 to 20 MPH. If I were riding in the rountry in the dark at higher speeds I could see that a slightly tighter beam might be better, but I am VERY pleased.

Happy riding,
André

akatsuki 10-08-07 11:34 AM


Originally Posted by Geekage (Post 5293867)
The problem with using any kind of rechargeable battery as a voltage regulator is that you can vercharge and destroy the battery, so you'd probably want some sort of regulator in there anyway. It would be nice to actually fit a battery charge circuit in there, say some off-the-shelf Maxim chip, but that complicates it a bit.

Also, yeah, regular NiMH batteries lose something like 1% of their charge every day, but there are newer "hybrid" NiMH batteries that, while being rated as much lower power, lose only 15% of their charge annually. I've bought some sets for my occasionally-used flashlights and headlight.

So would it be better to take an off-the-shelf smart charger and somehow wire it in? I would much rather use an LED based lighting system with a hub, but the Solidlights are way too expensive to justify.

bmike 10-08-07 11:37 AM


Originally Posted by akatsuki (Post 5414247)
So would it be better to take an off-the-shelf smart charger and somehow wire it in? I would much rather use an LED based lighting system with a hub, but the Solidlights are way too expensive to justify.

check out the d'lumotechs. LED, decent light output.

HardyWeinberg 10-08-07 12:22 PM

Can you hang 2 lights off a bracket coming under cantilever brakes, or must, if you are using 2 lights not on the handlebar, they be attached to the fork blades? I am wondering if I have enough vertical clearnace between fork racks and canti pivots to squeeze lights in... I am pretty sure my pitch-black heavily littered MUP would require 2 lights, not just one.

Michel Gagnon 10-08-07 09:43 PM

I haven't seen a "standard" fork-crown bracket that allows one to mount two headlights. There are, however, a few possibilities, most of which are described on Peter White's website.

To that, i would add my own comments and suggestions.

1. I have tried a main light at the fork crown and a secondary by the side of the wheel. While most people don't seem to be bothered by the shade of the front wheel, I am. I find it easily camouflages potholes, especially when riding with a single headlight... which happens often because I'm not a speed bullet. So no fork-mounted headlights for me.

2. A headlight too close to the side of the tire gets dirty from rain or snow very quickly. Placing it above the fender solves the problem.

My own setup – and how it evolves over the years – is described on this page. Just make sure that the lights are placed in a way they won't get banged when the bike steers completely (i.e. when parking).

HardyWeinberg 10-09-07 09:49 AM

That is a great website, love the angle brackets. Thanks!


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