In article <mn.1c797d5a2b10b110.39...@yahoo.co.uk>, Mark \(MSA\) wrote: >Wow, you guys really are something else! Great info, and some great >links.
>I started off thinking rechargeables would provide better light,and be >the easier option, then I changed my mind to a B&M S6 bottle.
>Now I've read the last few posts, I really think I want a hub (they >provide more 'power right?).
They have two advantages: i) they are generally more efficient than bottle dynamos, so for the same amount of light power you have to put in less pedal power (though they both vary - a Dynotec S6 bottle dynamo will be as efficient or more so than a cheaper hub dynamo). ii) they can't slip unless the wheel actually skids, so by using two lights at high speed (and putting twice as much work in), you can get twice the light out. Most bottle dynamos can't handle that. (B&M do do a 12V dynamo and light set (it won't work with standard dynamo lights), but it costs more than a SON.)
Bottle dynamos have some advantages: i) if you aren't using them, they have no drag at all, where even the best hub dynamos have a little. If you hardly ever cycle in the dark but want something that's ready whenever you do, a bottle might be better for that reason. ii) if you don't mind the lower efficiency, they can be cheaper. iii) they work on tadpole trikes where fitting a hub dynamo would be tricky or impossible.
>So, back to the hub dynamo. I 'think' for now I will buy a Shimano, >run it for a while and see how I get on. Is the drag and the 'output >of the Shimano similar to the SON 28, or would I be losing out? >Keeping the price lower if possible (if it's false economy then please >tell me) which Shimano hub should I go for?
How much you lose out depends which Shimano hub you go for. IIRC Sheldon stopped selling the SON because he thought the DH-3N70 was very nearly as good for quite a lot less money. (The earliest Shaimano hubs weren't as good.) I've never seen a SON owner wishing they hadn't spent the extra money, but nor have I seen a Shimano owner wishing they had.
If you like knowing you have the very best regardless of cost, go for the SON. Otherwise I suspect the higher end Shimano would be fine. (The low end Shimanos aren't _bad_, but if you are prepared to even consider a SON, you probably want the better ones.)
> > in message <mn.1c797d5a2b10b110.39...@yahoo.co.uk>, Mark (MSA) > > ('onyerbikem...@yahoo.co.uk') wrote:
> >> Now I've read the last few posts, I really think I want a hub (they > >> provide more 'power right?).
> > Not necessarily. But they produce it in a reliable and fuss free fashion, > > and are a lot neater.
> So let's assume I want to use a double front light and no rear light.
> Would a Shimano DH-3N71 hub do this better than a B&M S6? Aesthetics > aside for now.
yes, as the hubdynamo will not slip. To achieve the same with the S6 you have to increase the pressure on the roller, which will hurt the efficiency (and the tyre) --- Marten Gerritsen
Simon Brooke <si...@jasmine.org.uk> wrote: > in message <mn.1c797d5a2b10b110.39...@yahoo.co.uk>, Mark (MSA) > ('onyerbikem...@yahoo.co.uk') wrote:
>> Now I've read the last few posts, I really think I want a hub (they >> provide more 'power right?).
> Not necessarily. But they produce it in a reliable and fuss free fashion, > and are a lot neater.
What the main said. They are also far more 'fit and forget' than even the best bottle dynamos. A very important feature for commuting. That's why I use a hub dynamo for commuting anyway.
-- Arthur Clune PGP/GPG Key: http://www.clune.org/pubkey.txt The struggle of people against power is the struggle of memory against forgetting - Milan Kundera
I submit that on or about 3 Oct 2005 02:10:10 -0700, the person known to the court as "iakobski" <goo...@handsonit.co.uk> made a statement (<1128330610.553643.241...@g49g2000cwa.googlegroups.com> in Your Honour's bundle) to the following effect:
>>> A SON with a B&M Lumotec as primary and a SON E6 headlight as >>> secondary is my recommendation. >Can you expand on that please? I've just ordered SON generator + E6S + >E6Z - but it's not too late to change the order (he's ordered the hub >first to build the wheel onto).
The B&M has a standlight. You can use a cheap LED instead and have two E6 headlights, but actually I quite like the coverage you get form the two different beam patterns
>And before anyone says "more money than sense", my car is so >inefficient that I will only have to commute 2400 km to have paid for >it in "saved petrol".
As if anyone would accuse a SON buyer of having anything other than exquisite taste!
Mark (MSA) wrote: > My first question is, at 18-20mph, would the output from a front light > only (will use battery on the rear) be significantly better than my EL300?
Lots and lots. I rode all night on the Dunwich Dynamo in July and never had trouble seeing at any speed. It's amazing the way the dynamo lamp lights up several hundred yards of cat's eyes, just like a car would. The halogen lamp colour is also much better for seeing by. However hi-tech the LEDs might look, a blue glow scatters more easily in mist and adversely affects your night vision.
> Would I be better off paying the extra for a Schmidt hub rather than a > Shimano? What's the difference, weight, quality, drag, output?
I have a Schmidt, but the answer is probably no. The Shimano is *slightly* heavier and has *slightly* more drag.
> Guess I will wait to see if anyone has any comments on the above, but I > would also like to know the best light to run off the dynamo, presuming > a B&M fitted with a 3 watt bulb would be best?
The Schmidt E6, because of its tight focus, is noticeably superior to the B&M Lumotecs (which use the same optics, oval or round). I don't have experience of the new B&M LED dynamo lamp but it may be brighter than the E6. I doubt it's as well focused though - you can only do that with a small filament.
> I work in Germany frequently, I'm presuming this gear must be cheaper > over there?
> The Schmidt E6, because of its tight focus, is noticeably superior to > the B&M Lumotecs (which use the same optics, oval or round). I don't > have experience of the new B&M LED dynamo lamp but it may be brighter > than the E6. I doubt it's as well focused though - you can only do that > with a small filament.
You'er right, the BuM Topal is pretty dam' bright, but gives a big splash of light, which is nice, plus a great strobe effect at about 2kph as the main LED is switching in... I'm gonna fit a supplementary E6Z, though. -rory
>>Ah, I wasn't aware of the existence of the DH-3D71.
>Forget about the difference between DH-3N70/3D70 and DH-3N71/3D71. >Measurements by me and other people showed no substential difference in >drag between both types. The only difference is a little more electrical >power of the 71's at slow to medium speed.
I suspected Shimano's claims were exaggerated or misleading, but it's good to hear actual measurements. Thanks. (But as someone who often travels at a slow to medium speed, I might bother to go for the 71 anyway.)
>>S>resistance and the result is amazing: They have a 40 % lower rotation >>S>friction than the current models (DH-3D70, DH-3N70 and DH-2N70) and
>The amount of mechanical *friction* is relative low.
[...]
>>S>even 75 % less resistance than previous models when the lamp is turned off!
>This is true (whithin measurement accuracy). The HB-NX32 takes up about >8-9 Watt at 30 kmph when switched off. >The SON28 has a no-load drag of around 1.5 Watt at 30 kmph.
I'd interpreted "previous models" as meaning the 70 range from the previous sentence. I knew there was an earlier Shimano one that actually had more drag when turned off at high speed. (I don't know the model number, http://www.myra-simon.com/bike/dynotest.html says "Inter-L", but you probably do.)
>> So let's assume I want to use a double front light and no rear light.
>> Would a Shimano DH-3N71 hub do this better than a B&M S6?
> The S6 provides a well regulated 6.4 Volt AC. It is not possible to power > two 6V3W headlamps with it. The advantage of the S6 is lots of power > output at low speeds, very good efficienye for a sidewall dynamo and the > possibility to increase pressure force against the tire to reduce the > likelyhood of slippage in wet conditions.
> Hub dynamos like DH-3N70/71 or SON28 will power two headlamps connected in > series. Just using a conventional Lumotec as a secondary headlamp, it > takes about 25 kmph in a 700c wheel to reach full brightness of both. With > the E6-Z as secondary lamp about 18 km/h will be enough. Reason for the > difference is the series-capacitor in the base of the E6-Z.
> Andreas
OK, I've made the decision, I'll be picking up a SON 28 next week!
I really want to run 2 front lamps, are you certain I do not have to go for a specific secondary lamp such as the E6Z?...unless I want brighter lamps at the lower speeds?
I will need some advice on wiring these properly, but I shouldn't think it's too much hassle?
Last decision is how to mount the lights. I would like something that I can remove quickly at the end of my commute. My initial idea was to mount both lights on a Minoura Spacegrip...but that's not exactly quick to remove is it! Anyone seen something similar, or have any other ideas on a quick release mount for 2 lamps (or 2 seperate ones)? My other idea was to use the base of an old Cateye lamp I have, the QR works well, perhaps I can mount a plate on top of the bottom piece of the lamp and fix the Lumotecs to that.
When it's finished, I will provide photos and an accurate report on how it works for my commute. Hope it's positive!
-- Mark _______________________________________ Nerves of Steel, Heart of Gold, Knob of Butter
> OK, I've made the decision, I'll be picking up a SON 28 next week!
> I really want to run 2 front lamps, are you certain I do not have to go > for a specific secondary lamp such as the E6Z?...unless I want brighter > lamps at the lower speeds?
The switch in the basic lumotec is wired wrongly for the second lamp. You need a switch in parallel with the lamp to short it out, not a switch in series to let current flow at all. You might be able to disassemble the lamp and rewire it internally, but I don't know how user-adaptable these are.
> I will need some advice on wiring these properly, but I shouldn't think > it's too much hassle?
Wire from SON to first lamp with normal switch, out of that one to second lamp with parallel switch, out of that to SON. Dead easy.
> Last decision is how to mount the lights. I would like something that I > can remove quickly at the end of my commute. My initial idea was to mount > both lights on a Minoura Spacegrip...but that's not exactly quick to > remove is it! Anyone seen something similar, or have any other ideas on a > quick release mount for 2 lamps (or 2 seperate ones)?
Nooo! It's a dynamo, the idea is everything is mounted permanently, nothing to forget, no connectors to corrode. Use bolts and things to mount the lamps. I'd probably mount them either side of the fork just beneath the brakes, but that isn't terribly normal.
> The switch in the basic lumotec is wired wrongly for the second lamp. You > need a switch in parallel with the lamp to short it out, not a switch in > series to let current flow at all. You might be able to disassemble the lamp > and rewire it internally, but I don't know how user-adaptable these are.
I'n not too hot on this but... If I wasn't bothered about turning off the secondary lamp (i.e., run 2 or nothing) couldn't I just leave the second lamp switch on all the time (or buy an unswtiched one), and virtually treat it as if it was a back light?
> Nooo! It's a dynamo, the idea is everything is mounted permanently, nothing > to forget
:-)
I get where your coming from, but 1) I wouldn't feel happy leaving it on there if I bike into London, and 2) my commute bike is also my Winter training bike and...oh, I guess that's not really a reason!
-- Mark _______________________________________ Nerves of Steel, Heart of Gold, Knob of Butter
Mark (MSA) wrote: > Last decision is how to mount the lights. I would like something that > I can remove quickly at the end of my commute. My initial idea was to > mount both lights on a Minoura Spacegrip...but that's not exactly > quick to remove is it!
It only takes two minutes to undo the retaining screws and slide the front half off, leaving the stub on the handlebar. Or half that time if only one screw is used (one seems to be adequate since they don't take the weight). An allen-key screws makes it even easier. I take mine off when going for a quick daytime spin. It might even be possible to make some kind of quick release skewer for it.
But I understand dynamo users usually leave their lamps permanently bolted to the bike. I did with the old lamp I used to have mounted on the forks. Not too easy to nick.
> OK, I've made the decision, I'll be picking up a SON 28 next week!
> I really want to run 2 front lamps, are you certain I do not have to go > for a specific secondary lamp such as the E6Z?...unless I want brighter > lamps at the lower speeds?
I believe that the secondary specific lamp lets you choose between running 1 lamp (more light at low speeds, like up a hill) and running 2 lamps in series (uses any excess dynamo output, 2nd lamp has different optics for a longer beam).
I would suggest 1 Lumotec with a standlight to use all the time , 1 E6Z as a secondary. As I understand it, the Lumotec beam is not as tightly focussed as the E6, illuminating a wider area immediately in front of you and letting motorists see you from a wider range of angles. The E6Z has a more tightly focussed beam which will reach a longer distance, for travel at higher speeds. The E6Z is designed to operate in series with a primary, when you shut it off the current is sent straight through as if there were only one lamp in the circuit.
> I will need some advice on wiring these properly, but I shouldn't think > it's too much hassle?
> Last decision is how to mount the lights. I would like something that I > can remove quickly at the end of my commute. My initial idea was to mount > both lights on a Minoura Spacegrip...but that's not exactly quick to > remove is it! Anyone seen something similar, or have any other ideas on a > quick release mount for 2 lamps (or 2 seperate ones)? My other idea was > to use the base of an old Cateye lamp I have, the QR works well, perhaps I > can mount a plate on top of the bottom piece of the lamp and fix the > Lumotecs to that.
The Lumotecs come with a bracket to mount the lamp at the fork crown, which is where mine is. If you have caliper brakes the bracket will mount onto the bolt attaching the front brake and front fender/mudguard to the fork. If you have cantilever brakes you use a different bracket but attach the light to the same point. Both brackets are supplied. Some people mount the secondary light on the fork blade, just high enough to reach the switch easily. The fork crown mounting point works really well, it puts the light right where I want it. If you really needed to remove the lights quickly at the end of your commute you could probably carry an Allen wrench , unbolt the lights and disconnect the wires and leave the brackets attached. -- mark
>> The switch in the basic lumotec is wired wrongly for the second lamp. You >> need a switch in parallel with the lamp to short it out, not a switch in >> series to let current flow at all. You might be able to disassemble the >> lamp and rewire it internally, but I don't know how user-adaptable these >> are.
> I'n not too hot on this but... If I wasn't bothered about turning off > the secondary lamp (i.e., run 2 or nothing) couldn't I just leave the > second lamp switch on all the time (or buy an unswtiched one), and > virtually treat it as if it was a back light?
Depends on how fast you go. If you turn the second lamp on when you're going too slowly, neither lamp will give much output whereas a single one would work. I don't know the cutoff speed when the second one starts to work well, but it's higher than the speed I climb some hills, or possibly more relevant to you, than the speed you can drop to while manoevring in traffic.
>> Nooo! It's a dynamo, the idea is everything is mounted permanently, >> nothing to forget
> :-)
> I get where your coming from, but 1) I wouldn't feel happy leaving it on > there if I bike into London, and 2) my commute bike is also my Winter > training bike and...oh, I guess that's not really a reason!
Vandalism or theft? The former is a reason, I wouldn't worry about the latter - dynamos are deeply unfashionable. Do you remove your derailleur when you park? It's about as easy to remove...
> Depends on how fast you go. If you turn the second lamp on when you're going > too slowly, neither lamp will give much output whereas a single one would > work. I don't know the cutoff speed when the second one starts to work well, > but it's higher than the speed I climb some hills, or possibly more relevant > to you, than the speed you can drop to while manoevring in traffic.
For me it is 10mph, but oddly (recall I have a B&M oval plus) when I slow the led on the oval plus comes on and the secondary lamp just works perfectly. It could be cooking the electronics in the oval plus but since I very rarely drop this slow on my commute I've not concerned myself with this.
"Mark (MSA)" <onyerbikem...@yahoo.co.uk> wrote: > I would like something that I can remove quickly at the end of my > commute. My initial idea was to mount both lights on a Minoura > Spacegrip...but that's not exactly quick to remove is it! Anyone > seen something similar, or have any other ideas on a quick > release mount for 2 lamps (or 2 seperate ones)?
I've uploaded a few pictures of my old system (NX30 with two Lumotecs) that I set up to be quickly removable. It's all a bit rough and ready, and apologies for the picture quality.
I made the spacegrip from a piece of old mtb handlebar and one of the clamps from a pair of Cinelli Spinaci. The lights are mounted on short brackets attached to Vistalite quick-release clamps with a short bolt and nylock nut:
The big advantage is that the beams can be directed on the fly by rotating the Vista clamps around the bar, and by pivoting the brackets on the clamps. They can be set to overlap to give more light in one spot, separated to give a broader pool of light, or one in front of the other to illuminate further ahead at higher speeds.
The grotty Monoprix bag was both rain cover and theft deterrent.
There were no switches in this setup: both lights were on all the time, night and day.
If you wanted to be really smart, maybe you could engineer some kind of "hot shoe" attachment.
Clive George wrote: >"Mark (MSA)" <onyerbikem...@yahoo.co.uk> wrote in message
>> I'n not too hot on this but... If I wasn't bothered about turning off >> the secondary lamp (i.e., run 2 or nothing) couldn't I just leave the >> second lamp switch on all the time (or buy an unswtiched one), and >> virtually treat it as if it was a back light?
>Depends on how fast you go. If you turn the second lamp on when you're going >too slowly, neither lamp will give much output whereas a single one would >work. I don't know the cutoff speed when the second one starts to work well, >but it's higher than the speed I climb some hills, or possibly more relevant >to you, than the speed you can drop to while manoevring in traffic.
Which _might_ not be a problem if all the manoevring in traffic is in streetlit areas. Either a D'Lumotec LED primary or a E6-Z secondary might reduce the problem. Or use a battery LED light as backup/standlight/low speed light, giving you something you can easily take off the bike to use as a torch to change a puncture or to change a bulb in the dynamo lights. Though then you lose some of the "always there, no charging to remember" advantage of the dynamo system.
I submit that on or about Tue, 4 Oct 2005 17:20:45 +0100, the person known to the court as "Clive George" <cl...@xxxx-x.fsnet.co.uk> made a statement (<4342abed$0$73617$ed261...@ptn-nntp-reader03.plus.net> in Your Honour's bundle) to the following effect:
>The switch in the basic lumotec is wired wrongly for the second lamp. You >need a switch in parallel with the lamp to short it out, not a switch in >series to let current flow at all. You might be able to disassemble the lamp >and rewire it internally, but I don't know how user-adaptable these are.
I wouldn't bother - you want the switch near at hand anyway.
I'd recommend the Lumotec as a primary and an E6 as secondary. The combination of the two beam patterns is useful (IMO) and the SON lamp has better optics for distance, while the B&M is somewhat better for close-up (again IMO). Plus the Lumotec has a standlight and the E6 does not.
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