Jeffbeerman2

I have a decent AA LED light setup, but I am curious about Dynohubs after reading another thread. I am always trying to make my bike "perfect" . It would be awesome to not have to worry about plugging in the batteries when I get home, then loading them again before I leave. the battery lights would make a fine helmet light as an extra supplement. I just want to not worry about lighting. Harris lists a ready-built wheel for $175, and I would be willing to spend that (and more) to insure that I am always well lit this winter. I have several questions.

first, can these be used to power the lights I already have? I don't know squat about electricity. I have a 2xAA fenix that uses 3v. I have a 4xAA 5w DiNotte that uses 6v. From what I read, the Shimano hub output is 6v. Is it realistic to power the DiNotte with a generator hub?

If it isn't possible to wire a generator to my dinotte, I want to get a full featured light. the light setup on the Breezer Uptown and one of the lights on the Harris site say that they automatically switch on at dark and have a "stand light" that stays on while stopped (the "LT134 Lumotec Oval Plus Senso with Standlight"). I also like that it doesn't mount on the bars. I prefer not to have the everyday light mounted on the bars.

I looked at the busch and Muller site, and they list a new item called LUMOTEC IQ Fly senso plus. The oval model on the Harris site is rated at "17 lux". The LED IQ fly model advertises 40 lux. that is quite a difference. Does anyone know of a US retailer that sells this item? I tried Google with no luck. Can Harris order these? It wasn't on their special order page but I thought it might be too new.

If it switches on automatically, it would be awesome to have the rear light running automatically at dark also. Batteries on my superflash run nearly forever, but I have to get off to switch it on. If I'm in for a penny...

If I get this type of light setup, will the auto-on feature on the headlamp switch on the rear light also? What recommendations do you have for rear lights powered by the dyno hub? Is it silly to run hte rear light on the dyno?

randomgear

I think B&M is distributed by Peter White in the U.S., he likely would know best about the IQ Fly plus. For some reason, I thought I had read on the B&M site that it wasn't available until this fall -but I can't seem to find it know.

Jeffbeerman2

When I googled it, I found a couple european retailers. I assume it is out already due to that. The B&M site does say it will be available fall 07

doraemonkey

As for powering led lights: leds are diodes that take direct current with a certain polarity. Dynohubs are usually AC (alternating current). So that means that you can't just plug in your leds to the dynohub, but there are methods to convert the AC to DC or mono-polarity.... There are also issues on current limitation, however I am not an electrical engineer (IANAEE).

Here is an example of a dynopowered LED light: https://www.solidlights.co.uk/products/1203d.php I haven't tested it because, well they are a little expensive.

rhm

When you take a battery powered headlight and try to rewire it to work of the dynohub, you are basically getting off the well marked trail and bushwacking. You're on your own. If you know what you're doing, or are willing to learn from your mistakes, you'll be fine; but you won't get much help from the LBS or even from Peter White.

I don't know the DiNotte, but I have taken working 6-volt battery lamps and ruined them in an attempt to attach them to the dynamo. The problem is usually the switch; I've found that the switches on 6-volt battery powered lamps don't work with the 6-volt AC of the dynamo.

As for LED's... you don't necessarily have to change the Dynohub's AC to DC to run LED's; but if you don't, the LED will flicker visibly at low speed. At high speed the flickering is so fast you can't see it.

n4zou

I am using a Mag-Lite 2 AA flashlight as a bottle dynamo powered headlight. It's not very difficult if you can solder, use a hacksaw, and a drill press. I just used a simple LM317 regulator with a bridge diode rectifier, capacitor, and two resistors. Using an LM317 is not a very efficient way of doing things but in this case it will protect the electronics and LED in the flashlight from too much current and voltage when the dynamo is running at high speed as in down a hill. I now have over 100 miles on the test setup and have ordered better parts and a real 1.5-watt star LED for my final version.


https://www.bikeforums.net/electronics-lighting-gadgets/339965-dynamo-powered-3-watt-led-flashlight.html

Jeffbeerman2

Awesome! Thanks for the link too, I guess I searched the wrong forum section initially. I'll try to work on getting this together soon. I can use my fenix, it already is using a plastic lock block (and the fenix is crazy-bright using 3v). If I am confident after gathering/assembling everything, I'll order the wheel. I could always order a made-for-dyno light later if I fail

Sheldon Brown

It would work, but likely be rather dim at lower speeds. Worth a try if you're handy with a soldering iron and shrink tube. By the way, "Dynohub" is a Sturmey-Archer trademark. ;-) I prefer to call them "generator hubs."

A lower mounting position casts potholes* and other road hazards into sharper relief, because of the shadows they cast.

See: https://sheldonbrown.org/raleigh-inte...l-nexus08.html

I'm sure we can order these. Not familiar with that new model yet...

I really do not recommend wired tail lights. Modern self-contained "blinkies" are so reliable, and so parsimonious of batteries that I consider them a much more reliable alternative to anything that involves running wires along the bike from front to rear.

Sheldon "Generator Front, Battery Rear" Brown

Michel Gagnon

From past experience in the 1970s with wired front and rear lights, I too prefer a battery taillight. Two reasons:
– No wire twisted around the frame, which is ugly, difficult to hide and prone to break.
– As far as I know, the best wired taillights are about 1/2 or 1/4 as bright as a Super Flash, and there is no flashing mode; on rainy or foggy days, I do prefer a flashing taillight.

That being said, there are two advantages to a wired taillight:
– If you ride through tunnels, turning on the headlight also turns on the taillight (especially useful on a tandem).
– It lasts indefinitely, not just 60 hours. However, with rechargeable batteries, taillight autonomy almost becomes a non-issue.


In reply to other posters further up:

Before spending money on the newer Lumotec IQ, I would check these aspects:
– Whether it works reliably without a wired taillight.
– How efficient (or worthless) is the standlight.

If you read the Randon e-mail list (on Google), these are two issues which are a real problem with current LED headlights. If I remember correctly, the DLumotec works correctly by itself but may fail if used with an E-6 secondary headlight and no taillight. And the Inoled fails if used without a taillight. So how will the IQ behave without a taillight? We'll know when the headlight is around because it seems Europeans almost never use these lights without a wired taillight.

Sheldon Brown

I really do not recommend recharegeable batteries for taillight blinkies.

•Rechargeables don't last as long on a charge as disposables do.

•Rechargeables tend to self-discharge just sitting idle at a much faster rate than alcalines, and especially lithium cells.

•Rechargeables have a sharp discharge curve, that is, they put out pretty much full voltage until they are just about dead, then they drop suddenly and sharply. That's not a good mode for tail lights, because you can't see it while riding.

Lithium AA cells are the hot ticket for blinkys. They have huge capacity, much greater than alcalines. They also have very long "shelf life" and are the lightest batteries out there.

Sheldon "Lithium" Brown

K6-III

While true for almost all NimH rechargeables, there are a few exceptions.

The new Sanyo Eneloop rechargeables have significantly lower self-discharge rates relative to traditional NimH batteries (85% charge after 1 year). Unlike my former Energizer rechargeables, which would self-discharge in a number of days, the Eneloops have performed so well that I no longer consider other AA/AAA rechargeables. 2000mah in AA, 850mah in AAA.

CliftonGK1

So, I'm convinced from reading the reviews here that the Shimano 3N70/1 is a pretty great hub, and that the majour advantage gained by spending almost $200 more for the SON28 is in the longevity and maintenance.

I'm slowly going to replace parts on my commuter and switch over to a 3N70/1 hub. It's going to be my first foray into wheelbuilding, so I've got to get things like a spoke tensometer and a truing stand, that's why this isn't going to be a "get it done this weekend" project. I've been looking at building wheels for quite some time, and now I've got the opportunity to get started on it. I've also been wanting to swap over to dyno-lights.
I think I'm going to pair the 3N70/1 hub to the Lumotech plus with the standlight for the primary and a standard Lumotech secondary to light things up like stadium lights.

Michel Gagnon

About rechargeable batteries for taillights:

My strategy is to use 2 or 3 taillights and not change the batteries at the same time. So far it has been successful.

PaulH

The auto-on switch is quite a good thing. It also regulates the voltage - bulb life increases from weeks (unregulated) to years (regulated) I'm using the standard Lumotec halogen light with a B&M Standlight (LED) at the rear. The Lumotec is less efficient than a LED headlight, but it fususses to a very narrow bright beam. You could adapt existing lights, but it is much easier and more convenient to simply buy a quality headlight and taillight intended for this purpose. Also, purpose-built headlights and taillights include a capacitor so there is light when your are stopped at a stoplight. The sensor turns on both lights in twilight. You can also turn them on manually; this is a good idea on rainy days.

I prefer a steady taillight. When I am driving, I find it is more difficult to determine how far away a blinkie is, relative to a steady light.

Paul

Sheldon Brown

It is true that judging distance of a blinking light is more difficult. However, it is not clear that this is a "bad thing."

If you see a blinky (and you are more likely to notice a blinky than a steady light) and you're not sure how far away it is, you're liable to become more alert and careful in approaching it.

Sh el do n "Bl in ky" Br ow n

d_D

The LED will flicker at low speed even if you do rectify AC to DC. Unlike a filament that takes time to heat up and cool down LEDs can turn on and off much quicker. Adding a capacitor will help smooth out the supply to the LED and reduce the flickering.

For my light I just used a bridge rectifier and two 3W leds. IMO using additional circuitry to get a bit more light or stop the flickering isn't worth the hassle of making it robust enough to survive on a bike.

You should power the LED with DC to make sure it doesn't get damaged. From wikipedia.

johann

In Germany there are statutes mandating generator lights on bikes, and the rear light cannot be a blinky light. I've heard/read/somebodyś-cousins-brother-says that drunken drivers are attracted by blinkies, but have no references to back that up. Maybe that explains the classic neon-blinky "Bar Open" signs.

Iowegian

+1 to this suggestion. Even if the reverse bias breakdown voltage of the LED is higher than the 6V output of the dynohub, quickly removing the 'load' from the generator output can result in voltage spikes in excess of the rated output. These voltage spikes can't be good for an LED.

IIAEE (I is an electrical engineer)

CliftonGK1

Article 10 (From the Randonneurs USA rider's rules)

...Lights must be turned on at all times during hours of darkness or other low-light conditions (rain, fog, etc.). At least one of the rear lights must be in a steady (rather than flashing) mode.


I'm guessing there's some increased safety from running a solid rear light instead of a blinkie. I run 2 PB Superflash lights on my commuter rig: One flashing, and one steady.

fender1

I use both. I have a wired taillight run from a dyno hub, flasher attached to my helmet & one on the pannier which is mounted on the non drive side of the bike. I had a fellow cyclist tell me I looked like an ambulance. I also use a Supernova 3w LED for my headlight and have been very happy with it.YMMV

ginsoakedboy

That is hysterical !!! So the drunk just pulls on into you because he subconsciously figures you for a good place to get a drink ?!?

I'm going to ditch my neon "Budweiser" tailight straight away.