28 January 2009

Winter Storm In Effect

winter storm bicyclist
There is a winter storm warning in effect. The streets are nearly empty. My boss told me I could work from home today. I would have still ridden my bicycle in to work, as this man is, but I am concerned about the trip home. In the daylight I can see the ice, at night I need more light.

Good thing I have a plan for that!

Here's the plan: I have a dynamo front wheel being built. I have a front rack coming in the mail. Now all I need are headlights to run off the dynamo. My colleague showed me a copy of Bicycle Quarterly, which happened to have an article about modifying LEDs for use with a dynamo. Does anyone else have suggestions for me? I'd really like to have two round headlights, if that's even possible with a Sturmey-Archer dynohub. What shall I do?


cris said...

Hi Charlotte,

As you might know, I'm running a pair of Schmidt E6's on my ANT and have been mostly fond of it. The one thing that I do tend to miss is a standlight. Since the E6s have no capacitor, when I stop at a red light or stop sign, the lights go out, which can be a bit unnerving in urban traffic.

I built a dynamo wheel for my girlfriend for Christmas in 2007 and added in a Lumotec IQ Fly, which does have a standlight and by itself is almost as powerful as my E6 combination. This has done nothing to assuage the minor feelings of inadequacy in my own setup. But I do advise you, to invest in a standlight.

So long as your SA hub outputs at 6v, 3w, all of the standard dynamo light options are in play, including paired lights wired in series.

With that said, if you have your heart set on twin round headlights, your economical option is to get a pair of Lumotec halogens, which have an LED standlight. If you've got a lot of room in your budget, then you could also look at the new generation of round LED lights like the Schmidt Edelux or Supernova, but these are +$200 a piece.

Halogens aren't bad, but they do have the drawback of being a little less bright than LEDs and the bulbs burn out every 100 hours or so.

btw, if you want more information, I'd also highly advise checking out Pamela and John's bike light page. Your husband might be able to confirm that they're rather avid about their lighting and living two miles away from Harris Cyclery gives them a lot of options for test driving the cutting edge in bike lighting.

Charlotte said...

Wow, Cris, thank you!!

My husband thinks I'm crazy in all this, but, well, maybe I am. I thank you for pointing out the standlight issue, as I do want these lights to help protect me in urban traffic. It's best that they stay on to do that.

Thank you!!!

cris said...

I personally believe that anyone who participates in and completes PBP forfeits the privilege of calling other people 'crazy'. We all just become varying degrees of 'peculiar' ;)

I'm curious to hear your review on the Sturmey-Archer, btw. I think you're the first person I know who has one of the modern ones.

Charlotte said...

Very good point!

That very 'peculiar' man will be building me the wheel, however it's with a beautifully refurbished vintage Sturmey-Archer, so I'll be able to comment on running those with modern lights. Good thing, because I now have two and need to decide whether to refurbish the second one on "mom's bike" (which I'm not ready to give her).

As an aside, after PBP (and before sleeping) he called me from Paris and said "never again". He's already changed that position. I hear PBP is a bit like childbirth in more than just that way. :)

Carice said...

I'm intrigued by this option, http://www.instructables.com/id/High_power_LED_bike_head_light_with_integrated_hea/

but I'm not completely sure how to convert it to a 3W dynamo (buy a different LED? buy a different controller? just expect half the light? ) I also feel that a standlight is really important and I have no idea how to add a capacitor to something like this.

I have an inadvertant collection of headlights- a switchless Lumotech plus for when I had a sidewall generator. A switched lumotech plus for when I got a dynohub, and now I'm using one of the "retro" B&M lights which goes nicely with my bike, but is much more of a "be seen" light- not for discerning black ice at the edge of the road. I need to put the extras on Craig's list- let me know if you want them for cheap....

I rode on Monday and it was icy in the margins on the way home. Definitely didn't try today, although I saw a lot of brave souls going by in the bike lane in front of my house while I shoveled. More than black ice, I'm terrified of someone in a giant steel cage losing control and squishing me against a 3' tall icebank or parked car.

Carice said...


That looks a lot like the view from the Whitehead looking across Galileo Galilei way....

Charlotte said...

You got it!

PS, thanks for the light links - I have to do some more research, for sure.

dr2chase said...

Hi, I also have light links of my own, but (based on my recent experience with a 3D71 dynamo hub) they are not ready for prime-hub-dynamo-time.

There's interesting circuits at http://www.pilom.com, but I am not sure if those are the ones you want to use.

How much light were you imagining for output?

Are you picky about the color?

I can tell you, if you do go for LEDs, that the new CREE XRE white LEDs, mounted on little hexagonal pucks, are probably the way to go. They are efficient and bright at 350mA, and you get your choice of color temperature (cool white, neutral, and warm white). Heat sinking is a bit of an issue if you decide to retrofit them into some chic looking housing, instead of gluing them to an exposed slab of aluminum (the geek solution).

For tail lights, a Luxeon III red or orange-red is probably the way to go. I have been using one of those with no lens, it is dad-gum bright.

One minor problem that both my brother and I have noticed is that with the new LEDs, you really need low beams. They're too dad-gum bright. I don't care so much about the cars -- they're also too bright -- but it is annoying for pedestrians and other cyclists.

Dottie said...

Sorry, I don't have any light advice, but for ice I'm all about studded tires. Then it doesn't matter if you can see the ice coming. In Boston they should come in handy.

2whls3spds said...

I need to verify my information ;-) However IIRC the newer hubs have an over voltage protection system built in, the old SA Dynohubs do not. If there is any way possible I highly recommend the B&M LED headlights. I have the IQ Fly Senso Plus the difference between it and the halogens is nothing short of amazing. The Cyo is a round light in black and is available from SJS Cycles

There is more to an LED headlight than just cobbling together some pieces and parts. B&M puts a lot of thought and engineering into the reflectors and the mounts.


dr2chase said...

I'm a little grumpy about B&M electronics; one of their dynamos got wet in the rain and misbehaved, and that wetting appeared to cause eventual early failure. (It has no user-serviceable parts, they should have just potted the electronics in epoxy.) The Zinkins Dynashoe also broke. Response, both times, was not so satisfactory, so I just gave up on them. I was really, truly underwhelmed, especially given what I paid. I would certainly not recommend their sidewall dynamos to anyone.

From the POV of a lapsed EE, these are not hard circuits; the main problem is figuring out what the parameters are -- how much power WILL that hub generate at 35mph? That tells you how much power you'll need to dissipate, and from there you size your components.

Riffy said...

Hi Charlotte,
I also have a sturmey archer dynohub and am curious as to how you got on with regards to choice of led light.
This is an old blog so I'll not hold my breath for a reply. Fingers crossed I hear from you.

Rifraf said...

Well for any following in my footsteps or indeed my tire trail.
The GH6 dynohub is only 1.8Watts.
It wont do much for any but the smallest halogens. However it will
get great output from either the Schmidt Edelux or IQ Cyo B&M range.
It gives a great bang for buck method of lighting but is around .5 of a kilo heavier than its rivals which is substantial. Really only for the extremely budget conscious or vintage enthusiast (IMHO). As soon as funds permitted I upgraded to a Son Edelux hub.