Author Topic: How bright are dynamos?  (Read 11023 times)

Clive

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How bright are dynamos?
« on: September 29, 2005, 09:55:49 PM »
I've been commuting using Lumicycle lights for a few years now. Although they are probably overkill for road use I have got used to their brightness. How will a dynamo compare? Which dynamo set-up should I use for commuting on country lanes with little or no cultural lighting?
 

graham

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Re: How bright are dynamos?
« Reply #1 on: October 04, 2005, 08:52:38 PM »
We did the 'dun run' this year, using a Schmidt dynamo hub and Lumotec lamp with upgrade 3W bulb.

I thought the set up was adequate. Not as bright as the lads on their racers with Lumocycle's, but then they weren't using them all the time because the batteries would have been flat before they'd have finished. Well, we were riding from dusk to dawn with a food stop of about an hour in the middle.

Although supposedly carried out near a full moon, the weather was overcast so not much lunar illumination. We were obviously following other people's lights a lot of the time, which probably made a difference, but even so there was the odd bit on our own, under trees, at 30mph (I guess) downhill, where I was able to see enough to stay on the correct side of the road and not put the tandem into a hedge. So good enough. We took a spare bulb and didn't need it, of course. We even had one superfit lad draw alongside us and compliment us on the brightness of our headlight (before switching his Lumicycle on- and off again).
 

TonySmith

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Re: How bright are dynamos?
« Reply #2 on: October 13, 2005, 01:00:43 PM »
I find the single 2.4W B+M round headlamp gives enough light for about 20mph, more on roads I know well...but switch on the 2nd headlamp (3W E6) and I can go as fast as in daylight on a reasonably straight road and see details like mud, gravel & potholes. Only time I wish for anything better is on sharp bends where the narrow focus of the beam doesn't let me see around the corner.
 

acadvaphy

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How bright are dynamos
« Reply #3 on: September 07, 2009, 12:43:31 AM »
depends on how much i like the comic. some i will track down every issue, including reprints if they have new covers or interior art like elfquest

most of the time though i have trouble completing a 4 issue series without getting side-tracked, even if i liked it

pastafarian

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Re: How bright are dynamos?
« Reply #4 on: September 07, 2009, 09:40:41 AM »
The Supernova E3 together with the SON hub is a monster on unlit roads. In the city it is a bit of an overkill.

freddered

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Re: How bright are dynamos?
« Reply #5 on: September 07, 2009, 02:42:03 PM »
I have the B&M Cyo on 2 bikes.

All my night riding is on narrow, unlit lanes and they are plenty good enough, even in the wet.

I hear good things about the Supernova E3 but it's expensive.

On my next bike I'll for a Schmidt Edelux.  It has the superb reflector from the CYO but a bit more power and a bit more quality (and a bit more cost).

Summary, the CYO is good enough to ride through the Brecon Beacons and Snowdonia in the middle of the night, in the rain.

 

Fred A-M

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Re: How bright are dynamos?
« Reply #6 on: September 07, 2009, 05:57:44 PM »
I 2nd Pastafarian's statement on the Schmidt / Supernova E3 combo - not just adequate - absolutely awesome!
 

PH

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Re: How bright are dynamos?
« Reply #7 on: September 07, 2009, 07:46:49 PM »
To answer Clive's question, dynamo lights are now a heck of a lot brighter now than they were when you asked!

PH

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Re: How bright are dynamos?
« Reply #8 on: September 07, 2009, 07:50:23 PM »
Superenova users may like to know that there's a useful upgrade available either now or soon.

freddered

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Re: How bright are dynamos?
« Reply #9 on: September 08, 2009, 03:08:16 PM »
Superenova users may like to know that there's a useful upgrade available either now or soon.


I may treat myself to an uprated Supernova E3 if it comes in an Asymmetrical beam pattern (so I don't dazzle drivers)
 

Blacksail

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Re: How bright are dynamos?
« Reply #10 on: January 10, 2010, 05:54:24 PM »
I have an Edelux running off a Schmidt 20r hub (this is built into a 26" wheel). This produces a huge amount of light and importantly puts it down on the road where you need it. The beam is actually made up of 6 beams, the mirror has 6 curves to focus the light, the two middle beams overlap to form a single bright rectangle of light (a road shaped beam), two less bright beams go off at angle to give peripheral vision and finally the last two beams are spikes of light at almost 90 degrees which are presumably there to show drivers what they are about to drive into.

Worth noting that because of this asymmetric beam when you lean into a corner you do lose a lot of the peripheral lighting as this is now pointed too far down, there is still enough light see the way though.

If you want something too bright for the road try a Supernova E3 Triple, which will allow you to see everything around you but will blind ever cyclist, pedestrian and car driver coming the over way.

Andre Jute

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Re: How bright are dynamos?
« Reply #11 on: January 11, 2010, 01:27:34 AM »
THE HUB DYNAMO

Either a Shimano hub dynamo or the SON will be very good. I have both, the Shimano in two grades, one of which has better bearings. Unless you're a major tourer, the SON is huge overkill and I fail to justify its extravagant price every time I use the bike on which I have mine. Good for posing in cafe society though.

The major difference between the Shimano and SON dynamos is that the SON is supposed to see the bike out while the Shimano is built to last 40k klicks. Since a good Shimano dynamo costs less than a third, and sometimes only a quarter, as much as a SON, the decision rests on what sort of brakes you fit, and consequently how often your rims wear through and you rebuild the wheel. If you have rim brakes, there is little reason to splash out on the SON; just buy a new Shimano every time you rebuild the wheel, or every second time; if you fit discs and the rims will therefore possibly last as long as the frame, the SON might eventually justify its cost.

There are some slight differences between the dynamos in how much current they provide at any particular speed. Self-alleged speed kings claim the SON puts out more light at 25mph, below which of course no self-respecting cyclist rides. I'm a downhill racer who slows on the uphills, and I like the output curve of the cheaper Shimano better for providing more light at lower speed.

If you find output curves on the net, be careful on two counts. First, there are some old curves taken from when Shimano took over a Sanyo dynamo design, long outdated; a current Shimano dynamo is in every respect except longevity the equal of the SON. The second problem is that the data, if taken in Germany, is not truly independent because the magazine which published it didn't have the necessary test equipment and therefore used a SON employee and equipment to measure the tests! (I'm sure there was no deliberate distortion, but there needn't be; giving your own guys those slight benefits of the doubt which arise in every test adds up without any volition. The same applies to tests of lamps: Schmidt Maschinenbau, makers of the SON and the Edelux which is a jumped-up Cyo, see below, and BUMM have an incestuous relationship, and guess which engineer was involved in taking the lamp test measurement -- yes, the same Schmidt/SON/Edelux employee...)

By the way, though a good sidewall dynamo is now more expensive than an excellent hub dynamo, if you already have a good sidewall dynamo, there is absolutely no reason to throw it out. It works as well with the lamps recommended below as a hub dynamo, and might offer a weight saving if mass is important to you.

THE REAL QUESTION: THE LAMP YOU BUY
The question isn't actually the dynamo. In my opinion every bike except outright daylight-only racers should have a dynamo, and the common ones are all good. The real question is the lamp that you buy. You need two kinds of lamps. One flashes and makes you visible to drivers; those are normally battery lamps. The other kind throws light and is for you to see the road and obstructions by; there is absolutely no reason today why lamps to see by should not be dynamo lights.

Of lights to see by, powered by a dynamo, anything less than BUMM's Cyo isn't good enough. The lights that aren't good enough include recent halogen and LED lights thought fine until recently. The Cyo, of which the R or nearfield versions are the most useful for speeding around unlit lanes, throws out more light, and better shaped too, than the old 6V Volkswagen Beetle of fond memory. The R version of the Cyo has a useful reflector and a certain amount of (still inadequate -- it's a BUMM lamp after all) sidethrow while the 'racer' Cyo throws no more useful light on the road, nor any further, but lacks the essential facilities of reasonable sidethrow and reflector. The Edelux is an upgraded, more expensive version of the racer's Cyo in flashier dress, including a red that matches the red available on Rohloff hubs; very serious cyclists who have splashed out the extra report that they love the Edelux.

The Cyo has pass-through switching and connections for a LED rear lamp to be dynamo-powered as well.

If the Cyo has a fault it is that the horizon is too well defined, that there isn't enough spill above the horizon to see high-set road signs.

A GROWN-UP LAMP REQUIRES CAUTION
If you do buy a Cyo, be careful about how you set it up; it is strong enough to cause an accident. The law in most countries for dipped lights is something like a metre high horizon at a hundred meters. I used an empty supermarket lot to set up my lights and, in the complex of service roads on the way to the main road, found a car driver slowing to hang out of the window to inspect my lights objectionably closely. I tilted the bike to flash the lights through his eyes and said into his open window, "Park until your eyes recover, or I'll report you to the police." The answer was, "We are the f---ing police!" So I stopped to take their opinion on whether my lights are legal, and learned that this little rule of thumb is a pretty good guide, though my supplementary battery white flasher to the front should preferably be amber.

Andre Jute
 The rest is magic hidden in the hub.
For rare hub gear bikes, visit Jute on Bicycles at
 http://www.audio-talk.co.uk/fiultra/BICYCLE%20%26%20CYCLING.html
 
« Last Edit: January 11, 2010, 10:37:27 PM by Hobbes »

Grumbler

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Re: How bright are dynamos?
« Reply #12 on: January 11, 2010, 12:07:00 PM »
Thanks  Andre for your knowledgeable, explanatory and no bullshit post on this interesting topic. Most interesting for  those of us who are pondering the different options available to shed some light on our two wheeled lives.
 
Enrique
 

Andre Jute

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Re: How bright are dynamos?
« Reply #13 on: January 11, 2010, 11:08:49 PM »
Thanks  Andre for your knowledgeable, explanatory and no bullshit post on this interesting topic. Most interesting for  those of us who are pondering the different options available to shed some light on our two wheeled lives.
 
Enrique

Glad to give something back in return for help on subjects I know less about. We're fortunate that dynamo and affordable  battery LED lights have both just recently, and at last, become adequate; it seems that bicycle lighting is mature with the arrival of the Cyo to match the good hub dynamos available for the past decade, and I expect there is much more to come from cheaper LED lights. As recently as the year before last achieving a good lighting setup was tedious, expensive and heavy. Now, suddenly, excellent battery-free lights front and rear are on the verge of being cheap enough to describe as a necessity for every bike. I think these good new lights will revolutionize touring. Though I'm not a tourer, and I don't commute as I work at home, where I've always ridden at night rarely and reluctantly and fearfully, in the last year or so, with the advent of the Cyo, I've taken to riding at night for fun. We discuss the technicalities of cycling components but what really matters is that sense of gleeful liberation. -- Andre Jute