CityCyclingEdinburgh was launched on the 27th of October 2009 as "an experiment".
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I've purchased a dyno hub from ebay having got it home and had a look at the specs i've realised that shimano say it's only for 26 inch wheels. I had hoped to use it with a 700c wheel, think it'll work?
It's only rated at 2.4w so it's not the most powerful so I'm still debating keeping it or getting a more powerful one, but the cost with these things isn't the hub but building the wheel with my lack of skill.
It's a hb C050.
If it's the same as a SON then the difference will be you need to go faster to get the same output. If you're using an LED front lamp then you're not likely to notice the difference. Even at low speeds they are very bright.
The power regulation for my generators is done by the front lamp so I think the 2.4W thing is also to do with having fewer windings.
One of the annoying things about my Pashley is the back light is battery driven but I'm already carrying the generator hub. I might footer with it over the summer and see how well it drives a front/back set of lights.
Memsahib has vetoed expenditure so I'm not allowed to fit a BromSON/Edelux to my S6L Brompton.
By my calculations each emitter in series of a LED aray would see 0.4a instead of 0.5 with a 3w hub. So a unit of 3 would be out putting nearly 4.5w instead of more that 5.5w should make cooling easier. It probably won't be that noticeable only risk (i think) is that the windings are put under increased stress.
Any ideas if the hub would work with a 700c rim?
I'm surprised that (even) Shimano differentiates between 26 and 700c for this hub.
Using it for a 20" or 16" wheel is a different matter - which would be likely to cause problems unless you don't go very fast.
When you build your 700c wheel you won't be alone -
Ecorider 2.1 Men
It will work.
The difference in circumference between a fat 26" tyre and a thin 700C one is very small. In fact I think the current front tyre on my MTB might have a larger circumference than the one on my late fixed wheel...
You can run 20" dynamos on 700C wheels so a 26" one should be no problem...
Cool, thanks chaps.
I've just bought the first component for my winter commuting machine (as in, my existing bike with some extra lights on it...)
DH-3N80 dynamo hub which TBW will built me some nice wheels around.
I used a pair of cheapy battery powered LED lights last winter which were good for what they cost, but really didn't encourage me to do anything but ride directly home after work. I want something bright and reliable and "always there" so I can stray further from the commuting route during winter. Also something for some night rides in the summer would be nice!
Does anyone have any recommendations/thoughts for LEDs?
Should I go full 3W front light and batteries on the back, or 2.4W front and 0.6W wired at the back, with some backup flashers?
Personally (having done 2.4w with rear 0.6w), I would now go for putting all 3 notional watts into a front lamp and running a couple of battery rear lights.
In my experience: (1) it's difficult to keep the wiring and connections to the rear lamp fully weather- and spray-proofed in this climate; and (2) rear dynamo lamps are not very good compared with battery lights such as the SuperFlash or CherryBomb.
Cool, thanks. As the main point in shifting to dynamomo is to have a light to "see with" rather than "be seen with", it does figure that I should be putting all the electricity to the front. It will also make it easier and less complex to move the set-up between bikes.
Plus (AIUI) newer front LED dynamo lamps can cope better with the extra oomph - so the previous "need" to wire in a rear lamp has gone.
Fit-and-forget front and rear lighting is great, provided it works. Trouble is, if you do forget it, it does tend to stop working (at least the rear half) - and I found troubleshooting to be a bit of a b****r.
I wired a rear light the wrong way round once. I didn't know it was also using a common return via the frame which led to an interesting variation in the output. Once I figured it out it worked fine.
I've got a Schmidt Edelux and B&M tail light on the same generator (SON). It doesn't appear to take anything away from the front light. It's still raving bright. I'd usually have two unrelated lights on the back just in case anyway.
IQ Cyo is what I've got (possibly a newer version than mine at this link). There are more powerful lights if you have 2x or more cash to blow, but it's not necessary when you can already ride downhill at 40mph overnight in the back of beyond...
As for tail lights, my favoured (out of Smart, RSP Astrum and the Cateye LD1100 and this) is the B&M Toplight Line Plus.
Having a wired tail light won't make any difference to the headlight - mine draws 20mA out of the overall 500mA. In fact it's so good that I even use it (along with the Cyo) powered by AA batteries on the lowracer.
YMMV when it comes to your own bike and how it might be wired, though. I've never had any issues, compared with the many problems I've had with rear light bouncing off, cracking open, getting soaked through, and so on...
My only experience is with battery light or the B&M Cyo 60 with a rear Toplight but they are both the best lights I have ever owned. The Cyo 60 (front) has an asymmetric reflector that kicks the arse off a torch with the same lumen rating. All the light is directed at the road, not the sky. The Toplight rear light is as bright as any battery light and has a near-as-dammit 180 degree reflector so it radiates in a broad arc, unmissable by all but the biggest SMIDSY. Both are daylight visible.
The main problem with this setup; people telling me I have left my lights on. (is that a proper use of the semicolon?)
Newer B&M lights have an off switch to override the super cap.
This is useful in train stations as they aren't keen for people to show red lights on the platform. They claim it could be misunderstood as a stop sign. I usually carry a bag to cover the tail light but a wee switch would be nicer. When my current B&M breaks in a few years I'll get one like this:
http://www.bumm.de/innovationoriginal/linetec.html
I like a URL with bum in it.
is that a proper use of the semicolon?
No. :-) The clause preceding the semicolon should contain a verb and a subject and should stand as a sentence on its own were the semicolon replaced with a full stop. You could replace it with a colon to introduce a list, but that would require more than one problem in your following clause, and this would negate the 'main' adjective. Arguably you could use a colon after an auxilliary 'is' but it would be largely redundant because 'is' already introduces the second part of the sentence, and placing it immediately before a collective noun sounds awkward. It's probably best to dispense with colonnery altogether in this case!
Hurrah! The hub finally arrived (2nd class parcel post is not conducive to rapid delivery) and the Bicycle Works took precisely less than 24 hours to build them up into some wheels.
Now I just need the light!
I was looking at B&M IQ Cyo+ 40 Lumen with the "R" lens (the one that casts the longer light). Anyone have any experience? Worth the extra 20 bucks to go up to the 60 Lumen version? I don't even know what a Lumen is - how many carrots is that the equivalent to?
60 lumens isn't very much. My mtb light for off roading is more in the region of a 1k lumens, the one I'm building for my dyno light will be about 400 I think. It's three high power Cree LEDs, doesn't look pretty mind...
..know what a Lumen is..
Well, I'm not sure on the carrot scale but, and here I'm inspired by Arellcat's semicolonic explanaition..
A lumen is the SI derived unit for and amount of visible light and is the sum of the visible light emitted by a source of 1 candela of luminous intensity over one steradian. But that's probably not what you wanted to know!
A 60W light bulb (of the kind you can't get any more) is a source of about 1000 lumens.
Maybe more usefuly in this case, a domestic candle has a luminous intensity of about one candela and emits roughly evenly in all directions so emits about 12 lumens (4PI~12).
So you are going from ~3 to ~5 candle equivalents!
The increase from 40 to 60 won't seem as much as a 50% increase though because of the eye's non-linear response but more is always better, not least because cars seem to be engaged in some kind of headlight arms race that threatens to dazzle everyone!
Thanks for explaining - 60 lumens doesn't sound a lot. But this excellent comparison page from Peter White cycles has photos of the lamps they sell and the 60 lumen one looks well more bright than what I have just now and seems really bright to me. But then I won't be throwing myself down hillsides in the dark trying (not) to break my legs!
Depends what you want, my battery light on the roadie is (theoretically) 300 lumens and in pitch dark it's bright enough to ride at a moderate speed by but with dim street lights it can get a but muddied you can have a go with it and see what you think.
Of course there is more too it than just shear lumens reflectors are very important and good optics will do a better job of putting the lumens in the right place my light would be better off road as it's a nice round pattern that lights up the whole area not just the road... Probably not all that popular with drivers.
The Cyo models are specified in lux, not lumens. If it really gave out the light of 5 candles, it would be astounding to be able to descend at up to 40mph in the dark with it!
I have a 1000 lumen torch (in fact it's on the desk in front of me now) and I can't ride as fast with it as I can with the Cyo, which goes to show that the quality of the reflector is by far the most important factor.
I'm not using my Cyo right at this moment, so if you want, I could leave it in the Bicycle Works for you to pick up and try for a couple of days?
It's the 'N' (go fast) version rather than the 'R' (lights up the near field better) version, but that will give you an idea anyway.
@Dave that is a most generous offer that I shall take you up on. Will PM you
I've just found this quite usefull in explaining lumen vs lux.
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