Cycling in Sydney Australia
Dynamo lights
This morning/last night I had an epiphany regarding the need of a back up light source. I know someone who has a dynamo light. The only issue I have with it is that it stops working when the front wheel is not turning (he does also have the dynamo powering the rear lights on the rack and these stay on for 4 minutes). That may be with that particular light or that particular the dynamo.
The pros I can see are that the light does not have to have batteries. The light can be as powerful as battery powered lights. The cons are the weight and the resistance when the light has to be activated, as well as the length of time the light remains on. What I would like to know is does anyone on this site use a dynamo light. Could the dynamo light be a reliable back up or indeed a main lighting system
Replies to This Discussion
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Permalink Reply by Rob Berry on -
A dynamo isn't a reliable backup - it is a reliable main system. Battery powered systems would be back up.
Weight and resistance are negligble. The impact on performance seems to be roughly equivalent to a drop in speed of 1km/h depending on how fast you are travelling, so I doubt that most people would really notice anything. Most systems I know of will maintain illumination on both front and rear lights while stationary for some time, my wife's certainly does - Fiona has a Shimano DH-3N20 off the top of my head. So I would suspect that your friend's experience is particular to their set up and not dynamo systems in general.
My ideal bike would have a SON hub dynamo running either an Edelux, Supernova or Busch and Muller headlight. A little too expensive for me right now (but you certainly don't need to spend that much to get a dynamo system on your bike: http://www.cheekytransport.com.au/2012/04/complete-dynamo-wheels/)
For further reading on the subject:
http://www.peterwhitecycles.com/schmidt.asp - that is Peter White's Schmidt page, but there are a whole host of pages on various dynamo hubs and lights on his site which makes it a bit of a one stop shop on the subject.
http://veloweb.ca/resources/VBQgenerator.pdf - Bicycle Quarterly's analysis of the performance of a number of different dynamo systems, both in terms of light output and impact on riding speed.
Basically, I think the pros outweigh the cons significantly. Having functioning lights is one of the most important elements of bicycle safety, particularly as the days get shorter and more and more of us will be making trips in the dark. The energy sacrifice required to overcome the added weight and resistance pales into insignificance when you consider the advantages of strong, continuous lighting without the need for recharging or replacing batteries (not to mention that you can power more than just lights with a dynamo hub: http://cyclingabout.com/index.php/2012/03/list-of-hub-dynamo-power-...)
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Permalink Reply by Kim on -
Hi, I have a front and back dynamo light that stays on for a long time after I've stopped riding. I've lost count the number of people who have run after me to tell me I've left my lights on. I would never have any other lighting system.
As for your list of cons, I think you will find that the new dynamos don't have the problem with resistance. I don't notice any difference when the light is on or off. It's my main lighting system but I still pack separate lights when touring as, with any light system, they sometimes breakdown.
It's great not having to bother with batteries or worry that your light is not on as I leave mine on all the time. I highly recommend them.
The lights I have are Busch and Muller lights.
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Permalink Reply by Colin on -
I just got some Reelights recently, and they're working well. They're blinky "to be seen" lights, with a standlight, no batteries, and you don't need a special hub.
http://www.reelight.com/
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Permalink Reply by back street boy on -
I have reellights too, the one mounted to the hub. I I don't think they are bright enough as a primary light source though.
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Permalink Reply by PeterT on -
That reelight looks pretty easy and a non-invasive way to fit on an existing bike.
The SL150 is a solid light, supposedly coupled with extra magnets it's supposed to be brighter too. Not sure what that means in terms of blinding light duels.
I wish they had an easy comparison chart and brightness outputs between all their models like 500/600 ranges, looks like like 600s have inbuilt reflectors, but it's doing my head in.
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Permalink Reply by PeterT on
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What do you know? 1 year on and It so happens I saw a bike with SL100 in operation over Easter and was pretty impressed with the 'set and forget' nature of this device.
Not as a primary device but certainly as a 'to be seen' option.
http://shop.reelight.com/bicycle-lights/12-sl100-set/
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Permalink Reply by Colin on
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A year later, and my impression of Reelights is not completely positive. I've got them mounted front and rear on three bikes, so have a reasonable sample to make some judgements.
The models where the lights are mounted on the seatpost, front rack, handlebar etc. (ie, not mounted on the axle) have all worked reliably. However the axle-mounted ones have had somewhat dodgy standlights from day one - they were always intermittent, and have completely stopped working for many months now. They still work when moving, but the capacitor that powers the standlight gave up the ghost quite early on.
Conclusion: buy the non-axle mounted models. The others are crap.
Also, they're strangely finicky to install. One of those 5-minute jobs that takes a lot longer. (But I'm a bit of a klutz.)
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Permalink Reply by Neil Alexander on -
"Back in the day"... the Sanyo Dynapower was the go. It mounted under the bottom bracket and ran on the tread of the tyre rather than the sidewall as most other dynamos did then. Creating little drag, it put out enough power to run a 2.4W halogen headlight and one, or two, 0.1W taillights. It had no "standlicht" capability whereby the lights stay on when you stop but... thanks to the soldering expertise of electronics enthusiast and now SC member, Garryw, a battery back-up system could be added. Five C-cell Ni-Cd batteries and a rectifier enabled the system to operate at full power the whole time and the battery pack could also be recharged through the dynamo. I rode many Audax randonnees and my first Paris-Brest-Paris using this system.
In any event, no matter how noticeable (or not) the drag of a dynamo, there will be some effect, plus a weight penalty, and I would say that, these days, battery-powered LED systems are a better, brighter option, as long as you can recharge the batteries whenever required.
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Permalink Reply by robflyte on -
I still have a Sanyo Dynapower and it works very well, sits on an old Bennett. Using the same huge halogen front and rear lights as well.
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Permalink Reply by Garryw on -
(rises from ashes for this occasion):
I had been thinking about this yesterday too (not having been aware of this discussion), obviously some kind of telepathic as well as electrical connection going on. Specifically that you had wanted to use the 4Ah gel-cell which I objected to on account of the weight. I still have a 3W version of the Dynapower, these were rewound from the standard 2.4W by some long-lost bicycle place in the US - this enabled the use of a better tail light. For this one, the anti-slip modification was essential.
On a more modern point, for anyone using disposable AA or AAA alkaline batteries (cells, strictly speaking) Jaycar Electronics sell a really excellent little device that will recharge them (contrary to popular belief) up to 20 times. I've been using one for a while now, very successful, saves a lot of waste and pays for itself fairly quickly.
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Permalink Reply by Neil Alexander on
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Ah, yes. The good old 4Ah gel cell... I had almost forgotten.
Must say that the 5-cell Ni-Cd packs you made up had a longer operating life in terms of years, and I never managed to set my pannier on fire with the Ni-Cds as I did once with the gel cell (by accidentally short-circuiting the terminals with a set of keys -- blimey, that created a vile stench and nasty damage!) but the gel cell dropped conveniently and neatly into a bottle cage, whereas the Ni-Cds had to be strapped firmly down to a rear rack or onto a frame member.
I preferred to use the Ni-Cds on the touring/Audax bike in combo with the Dynapower while the gel cell directly powered a modified 6V headlight on the commuting bike where weight was not such a big consideration.
As you rightly allude, the Dynapower did have a few problems working in the wet, due to the metal roller slipping on the wet tyre rubber.
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Permalink Reply by baa baa on -
As you rightly allude, the Dynapower did have a few problems working in the wet, due to the metal roller slipping on the wet tyre rubber.
Please avoid the negative dynapower comments. I have two of these put aside and your general chitchat is now undermining my investment to potential punters .
Anyway good you didn’t mention mud or salt water or the damage that a stick can do to the fender thingy or the wires and how many spare globes you needed to carry on a longer ride "just in case".
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