Sweetbike (.org)

This is a big topic of much interest to lots of cyclists, and seems to inspire a lot of writing from everyone; myself included.  About Dynamos and Dynamo lights, this is a brief synopsis of what I have learned;  brief as I can make it.

First thing – everything about dynamos is decided in Germany.

Why do we care?

Because all the good gear is made for the German/Netherlands market.

There are roughly 120 million people in the Netherlands, Germany, and Denmark.  As of 2008, roughly 10~37% of them bicycle as a matter of course; compared to the US average of 1~3%.  (reference)   That’s a lot of bikes.  Out of necessity some very specific laws surrounding bicycle lighting have evolved, called the StVZO/TA.  The STVZO is a little insane to read and is bizarrely specific in places – but I suppose when you have roughly 15~30 million cyclists it makes more sense.  For the purposes of my little blog entry I’m going to grossly summarize and highlight a few relevant points.  (Just… shut up Fred)

• Bicycles are required to have lights front and rear.
• Rear lights are required to be red
• Front lights are required to be white or yellow.
• Front lights shall not be permitted to shine in the eyes of oncoming traffic.
• All bicycles over 11kg (23.2lbs) are required to have dynamo powered lighting.
• Front lights must use 2.4 watt bulbs (-20% to +10%) on 6 volt systems.

If you want a more in depth summary READ ON – those are just a few highlights.  But let me hit that big point again in case you missed it…

• All bicycles over 11kg (23.2lbs) are required to have dynamo powered lighting.

That means there are 15~30 million cyclists that are bound by law to have dynamo driven lighting.  That line right there, MAKES Germany/Netherlands the target market.  Period.

So… what does that mean for us?

It means that what happens in Germany/Netherlands effectively sets the tone for dynamo manufacturers around the world.  Dynamos and dynamo-driven products the are being designed foremost to adhere to the standards of the STVZO so they may be sold to the German/Netherlands market.  These products are later repackaged and resold to the rest of us after the fact.  Why are lights capped at 2.4W?  Because the STVZO says so.  Why do we use asymmetrical beams for lights?  Because the STVZO says so. Why do hubs saturate at 15kph?  Because the STVZO says so.   Though we in America aren’t bound by the STVZO manufacturers know that to violate the STVZO is to ostracize themselves from a market of roughly 15~30 million cyclists.  Nobody is willing to walk away from those kinds of numbers.

These aren’t necessarily terrible standards – there is some pretty great stuff to come out of it.  But all the above also adds up to mean your options getting into the dynamo game are somewhat limited, often expensive, and most of the good stuff has to be ordered directly from Europe.

Let’s talk gear.

Dynamo Hubs

There are effectively two ratings of hub dynamos – 3 Watt and 2.4 Watt.

(BTW – all this stuff is 6 Volts aka 6V)

3 Watt dynamo hubs are the most common.  They’re rated to generate 3 Watts at around 9mph on a 700c wheel.  That is enough juice to power a 2.4W headlight and a 0.6W tail light (STVZO Compliant!).  Common hubs in this category are  Shimano Alfine, Shimano Nexus, Supernova Infinity 8, and SP Dynamo’s PD-8 to name a few.

The 2.4 Watt dynamo is sort of a new thing.  As you might have inferred they’re only rated to generate 2.4 Watts (at around 9mph on a 700c wheel), but they have been given special dispensation by the STVZO so are still compliant.  While it’s true that these hubs generate less electricity, depending on the brand they can be anywhere from 50 ~ 200g lighter which is significant.

My kneejerk reaction is to say 3W doesn’t feel like much to work with – dropping to 2.4W seems like a big deal.  However, LED technology continues to evolve and become more efficient, requiring less power to do the same (or better!) work.  This means  when paired with the appropriate lights riders can use these lighter-weight/lighter-drag dynamos to achieve to similar effect.  Combined with the STVZO rubber stamp I think we’ll continue to see these hubs grow in popularity.  That drop to 2.4W may be less of a big deal after all.  Common hubs in this category are Schmidt SON Delux, the Supernova Infinity S, and theSP Dynamo’s SD-8.

A point of note – dynamo hubs feel “notchy” in the hand, but generally feel pretty okay on the bike.  Generally.  There may feel some very minor vibration in the bars while pedaling.  This usually gets better over time but the notchy feeling is how the electricity is generated and it’ll never go away completely (though you can get close).  Remember, a very small part of the rotational inertia is being diverted to generate electricity for the lights.  That notchy feeling are the magnets and poles being drug against one another to generate current.   In practical terms this means more electricity you draw, the more you need to generate, the more drag is involved.  With the lights off I forget I even have a dyno hub most of the time, and I feel it a little when the light kicks on.  The more stuff asking for electricity, the more you feel it.

So yes it’s a bummer that generating more electricity puts more drag on your bike but as I said before, LED technology is perpetually evolving and getting more efficient.  An LED bulb needing 2.4Watts to deliver 60 LUX this year may only require 1.8 Watts to do the same work next year.  By using more efficient LEDs we can look forward to using lighter dynamo hubs that exert less drag.  Which leads into the next part of this.

Lights

There are many different factors to consider with lamps, factors that I didn’t realize mattered until I started comparing them.

• Luminescence (how bright – measured in Lumens or LUX)
• Beam Pattern (Asymmetrical or Symmetrical)
• Light Color (Cool white, yellow, or clear)
• Standlight (How long the light stays on after you stop pedaling)
• Mounting Options
• Artifacts

In the land of dynamo lights, beam pattern is the thing that manufacturers are concerned about most.  Lights that are to be STVZO compliant must ensure that light aimed at the ground 5 meters away not spill light above the “horizon” (or into the eyes of oncoming traffic) more than 2.0 LUX.  That is very very little light, making this a pretty strict standard to meet.

In response, manufacturers have adopted a shaped (asymmetrical) beam that focuses the light downward to provide a hard “horizon” similar to car headlights.  Asymmetrical beams are generally better for pavement and bike paths, and nicer to other cyclists and motorists like the STVZO intended.

This is an asymmetrical beam.  Good for pavement but keeps the light out of the eyes of oncoming traffic – per STVZO standards. A lot more of the usable light is put where it’s most useful for urban cycling, on the path in front of you.

Asymmetrical beam pattern

This is a standard symmetrical round-beam like a flashlight uses.  There is less light on the path specifically, but more light in the surrounding areas.

Symmetrical beam pattern

Symmetrical lights are better for off-road since they highlight overhead things like tree branches and ninjas and shit. They’re not STVZO compliant but presumably you’re in the woods with this kind of light so oncoming traffic isn’t really a thing.  The thing that makes them great in the woods are what makes them illegal on pavement in Germany/Netherlands – their tenancy to spill light all over the What.

Let’s talk lamp models.

Busch & Müller – Lumotec IQ Cyo R N Plus
aka The Cyo 40

This was the first light I tested.  Nicknamed (by me) the Cyo 40, it’s a dynamo driven light that delivers 40 LUX in a STVZO compliant asymmetrical beam.  One of the “features” of the above lamp is that it diffuses the light to give you brighter nearfield (the area closer to the tires of your bike).  Not knowing anything about lamps I felt that it was not as bright as I’d come to expect from dynamo lamps, and the nearfield lighting wasn’t useful at all.  I did like it was that it was pretty reasonably priced around $70~, and later I’d realize that I loved the standlight, but I’ll go into that below.

The Cyo is the light that all other lights are invariably compared to – by the time I was finished I understood why.

Philips Saferide 60 - dynamo light

 

This light sucks.

I was so taken in by the reviews I ordered two of them thinking that my search was over.  On sale in the US, these are normally around $200 but (plus shipping) I ordered them from Germany and got them for $110 each.  According to the claims it was 20 LUX brighter than the Cyo 40, had a standlight that was better than the Cyo, and was reported to produce a much improved asymmetrical beam.  Since it was on sale, it was similarly priced to the Cyo.  Boom!  Search over!

No.

• Brighter than the Cyo 40?  Yes.  Still not awesome, but yes.  Brighter – it puts out 60 LUX.
• Improved asymmetrical beam pattern?  No.  For a crown mount the nearfield is WAY TOO BRIGHT.  (I’m a little unclear why there’s so much effort being put into illuminating the nearfield).    Additionally there are bizarre artifacts along the periphery that look like tiger stripes, and there are two big artifacts/deadspots in the illumination field in front of you – one where it transitions from nearfield to midfield, and a second one where it transitions from midfield to long field.  It’s strange.
• Awesome Standlight?  No.  The standlight lasts a long time, but only at about 10~15% of normal illumination.  It’s not even close to being bright enough.  For what you may ask?  When you have to dismount your bike in the dark to walk down a set of stairs, or navigate a barrier, or whatever.  The standlight cutoff is also set very high;  if you pedal slowly the headlight drops to standlight even if you’ve been pedaling for awhile.  This means it’s bad for slow or even the most meager technical riding – like say down a wheelchair ramp, or along a winding path with sharp corners, or in a group of people, or whatever.  Once you stop pedaling, you’re in the black.  It’s outright dangerous.  Combined with the crappy and supremely overbright nearfield lighting that has OBLITERATED your night vision, the the paltry 10~15% illumination of the standlight isn’t bright enough to overcome the sudden darkness you’re plunged into when you slow down or stop.  It’s almost worse than no standlight.

Since I ordered two of these stupid lights, I tested both against two separate dynamos (the Supernova Infinity 8, and a SP PD-8 – both are 6v/3w dynamos) just to make sure that it wasn’t just a bad light.  Identical results in both lamps.  What a piece of crap.

The cutoff switch didn’t work on either one of them either.

Last thing – that crown fork mounting bracket also sucks. It’s very thin at the bend and the bracket isn’t made of the best metal to begin with.  It’s also super wide where it mounts to the light meaning that you’re stuck with it since nobody makes a bracket that wide.  You can narrow the mount point by cutting away at the light to use a standard B&M or Supernova light bracket (which has become the defacto industry standard) – fortunately 2 minutes with a small saw was all it took, but still – more rotten to throw on the pile.

I sold these lights at a loss (with the above commentary!) just to get rid of them.  I’d have returned them to the store under other circumstances, but returning gear to Germany is generally cost prohibitive due to the shipping.

Small note – Fred is using one of these now with an under-rack mount, placed way in front of the wheel.  I was using a fork crown mount.   Mounted forward, under the rack like produced much better results.  The nearfield lighting isn’t blinding, the artifacts are less noticeable.  The standlight still sucks but his normal lamp is an eDelux which has a crappy standlight too, so for him this was a small improvement.

These lights are only good on commuter trails and in cities where it never gets very dark.  A light you can’t use in the dark.  Genius.

Supernova E3 Pro

I wanted to like this light.

It comes with a choice of a symmetrical (non STVZO ) or asymmetrical (pro STVZO) lenses, and at 60 LUX it was rated to be as bright as the Philips.

The last two lamps hadn’t exactly sold me on the asymmetrical lens thing, so I bought one with the symmetrical lens.

The craftsmanship of these things is just beautiful.  Everything from Supernova comes in a very nice tin container with molded closed-cell foam cutouts.  First class all the way – very impressive.  But there is a tradeoff.  The light is heavy as heck.  It probably weighs twice what other lights weigh.  Additionally these buggers are expensive.  After shipping and whatnot, it was $225 from Universal Cycles in Portland.  Ouch.

In terms of performance, I wasn’t as impressed as I wanted to be.  First thing I noticed was the light was yellow.  This is by design – the theory being that it’s better for your eyes over time or some such.  For me it just made for a bland and bleak experience.  Maybe it was 60 LUX, but because of the pale yellow lighting I couldn’t tell.  This was the first time I realized that light quality or color was a consideration that one had to pay attention to.  Oh the things you learn.

The standlight also wasn’t awesome.  It wasn’t as bad as the Philips, but it was nowhere as good at the Cyo 40 which was still the reigning champ in that category.

So I had some idea of what I was looking for now.  60+ LUX (or better!), with a good standlight, a clean beam pattern (free of artifacts), delivering neutral colored light.  Was still torn on the symmetrical/asymmetrical beam shape issue – neither had won me over.  Armed with this bit of experience I was then able to revisit my options and two lights floated to the top.  Read on.

*Incidentally I did talk with Fred and consider the ever popular eDelux headlight – he has one on his Rawland.  The conclusions we drew in a side by side comparison were that it puts out around 60 LUX of neutral colored light in an asymmetrical beam (good!) but the standlight wasn’t awesome and at $220+ from Germany, it was pretty expensive.  If I hadn’t found a cheaper lamp with a better standlight, the eDelux would have been my second choice.  ~ ED

What I’m running now

Remember, this whole topic has been driven by self interest.  I had two bikes I wanted to outfit, and approached the whole topic from that POV.  I had an offroad adventure bike I wanted powered up, and I wanted to outfit my road touring bike / daily commuter.  Two bikes with distinctly different functions, each with separate requirements.  It took a bit of trial and error to figure out what was going to work best for each.

Below are what I’m running on my touring bike, and my mountain bike.  Two different solutions for two different types of bikes.  If you’re reading this to find out what the best lights are for you – well, these are the conclusions I drew after messing with the above options.

Bridgestone XO-2

My 26in-wheeled road touring bike.  It’s also my daily commuter and meant mostly for urban areas like cities, alleys, bike paths and some rough stuff touring and camping.

Headlight – Busch & Müller Lumotec IQ Cyo Senso Plus – aka Cyo 60

It’s a 60 LUX light with an asymmetrical beam of neutral-colored light.  The Cyo 60 doesn’t waste any effort into trying to beef up the nearfield like it’s cousin the Cyo 40, and got 20 LUX brighter in the process!

Additionally it still has the same awesome standlight that Cyo’s are sorta known for.  The light drops to about 85% illumination a second or two after you stop, maintains that  for several minutes before gradually burning down over the next 10 minutes or so.  Long enough I’ve never cared or wanted it longer.  It also has an effective cutoff switch which the Philips and the E3 did not.  At $70 it’s also one of the more affordable lights out there – what a pleasant surprise!

The Cyo comes in a series of derivations and the truth is they’re all pretty reasonably priced.  They’re cheap, they work well, mount everywhere, don’t weigh much, produces neutral colored light, and has a kickass standlight.  Good for pavement, trail, and some minor singletrack or gravel road – I don’t know anyone not extremely happy with theirs.  I wish they made a symmetrical beam light one for mountain bikes!

What’s powering it?

Dynamo – (Shutter Precision) SP PD-8.

This is a new product on the market, and frankly it sounds a little too good to be true.  It claims to have the best of all the worlds.  It’s a 3 Watt hub that’s supposed to weigh the same as a 2.4 Watt hub.  It’s also supposed to cost about half what a normal hub with these statistics would normally command.  Let’s see…

Schmidt SON Delux – 2.4W/6V – weight 395G – Price $250~

SP PD-8 – 3W/6V – weight 410G – Price $130

Okay, it’s 15G heavier.  Whatever.  It’s a 3 Watt hub that’s $120~ cheaper than it’s 2.4 Watt competitor, and weighs an eeensy bit more.

So what gives?  I don’t know.  At first I didn’t love it.  The bearings felt cheap and the roll was inconsistent – you’d feel a bit of pulsing reverberation through the bars as you pedaled.  After putting a few hundred miles on it though I have no complaints now.  The bearing inconsistency went away and now it rolls and runs as nice as pie.  I guess it just needed to break in. I forget I even have a dynamo most of the time.

Combined with the Cyo 60 – it’s a kick ass formula.  $130 for the hub, $70 for the light.

Boom.

The Bad Monkey

(This has recently seen a big edit.  Read on.)

Next up, my 29er go everywhere/do everything adventure bike.  Needs to function everywhere, work well offroad, be bombproof and versatile.

This was a much harder bike to setup and I went a different direction entirely.  Well actually I went several directions, but ended up with two overlapping solutions.   A battery solution and a dynamo solution.

First, the dynamo solution.  The hub:

The Dynamo – Supernova’s Infinity 8

It’s a true 6V / 3W hub that has a clutch to disengage the dynamo when not in use.  Rotating the switch to “OFF” severs the power output and eliminates the rolling resistance (drag) or notchy-ness typically associated with dyno hubs. It is heavier than some dynamos, but the bearings are high quality and it performs well.  I like the on/off switch though most people seem to feel like the on/off switch is a solution looking for a problem, and simply adds weight and complexity.   (This is pointless I realize now, and I never use it – everyone was right).

The dyno lamp – The Klite mountain dynamo light

I bought one of Kerry’s mountain dynamo lights.  It is crazy, crazy bright and it’s not STVZO lensing which means it splatters light absolutely everywhere.  It kicks a lot of ass in the woods.

But man, it has zero stand light.  Absolutely none.  You sorta get this weak little oozy glow light if you look right at it, and that lasts forever, but that’s it.  It’s not useful at all.  I stop pedaling or even slow down and I am in the pitch black in no time.  We went bike camping out near Mt Rainier this summer – no moon and a meteor shower to watch.  I left at 11pm, loaded with camping gear to meet the gang who’d gone up earlier that day.  It was the darkest I’d ever experienced being outdoors.  You couldn’t see your hand in front of your face.  While I was moving along on washed-out paved forest service road, the light was awesome.  But the slower I went the darker it got.  If I stopped, I was in the black.  On the technical climbing stuff it was completely useless.  I ended up having to turn on the battery lamp when speeds got slow.

That said, I do like the lamp and I’m looking forward to what Klite is doing next.  He’s doing a lot of really neat work with lamps and chargers and I hope to see a light with better standlight and possibly integrated USB charging ability in the near future.  From him I think many things are possible, and I am following his progress with great interest.

Below is the (albeit crappy) pic with both lights.  Klite on the left (hard to see), the battery light on the right.

There is a lot I like about this lamp, but lack of standlight just kills me.  Without it, a supplemental battery lamp is absolutely critical.

Speaking of, let’s get to the battery system.

The Light – the Philips Saferide 80 - battery light

We’ve nicknamed it the Hand Of God.

It looks like the Philips Saferide 60, but it’s not.  This is the Philips Saferide 80.  It’s bigger, it’s battery driven, and it puts out a whopping 80 LUX of netural-colored light.  It runs on 4x rechargable Double-A NiMh batteries and has (among other qualities) a USB charger built directly into it!  You need merely plug into the back of the light and it will charge the AA batteries in place.  Way to think it through Philips!

This thing is awesome.  It delivers just a fantastic amount of light.  GREAT GOBS OF LIGHT.  What this light lacks in intensity per square inch, it makes up for in sheer quantity and throw.  It simply dwarfs other lights.

Strangely, it has a STVZO light shape which would normally disqualify it for mountain duty but it puts out so much light, it basically doesn’t matter.  It works great in the woods.  The run time on this is good too.  I haven’t done proper benchmarks but I want to say I’m getting betwen 5~7 hours for a full discharge on low, and between 2 ~ 2.5 hours on high.  Physically it’s a big hurkin light.  Looks dumb as hell to be honest – like you strapped a trumpet-looking search light to your handlebars.    But it performs very well and the handlebar clamp is of quality design.  I was pleasantly surprised to find that, despite the size and weight the Philips 80 doesn’t do a lot of wandering around on the handlebars.  This is the big complaint of the ever popular Niterider lights who are also quite heavy and bright.  Once it’s on, it’s on and you’re good to go.

PS – because it’s a simple handlebar mount I’ll often pull this off and put it on my Schwinn Paramount when going for a night time road ride.  There’s another plug for the versatility of this light!

So when the Saferide 80 isn’t kicking ass and taking names, what’s charging it?

This is where I’m still working out the details.  Originally the idea was to use a dynamo driven USB charger like:

The Charger – Tout Terrain’s “The Plug II”

It sits inside the steerer tube and acts like a replacement stem cap, the guts brilliantly hidden away and protected.

The USB charger is supposed to charge any number of things including a phone (which I use for music, maps, GPS, blogging, interneting and photographs – pretty much everything), a AA charger, and the aforementioned headlight.

The Problem?  The USB charger didn’t work as well as hoped.  

The charger only worked if you can maintain speeds over 9 mph on a 26in wheel, or 11mph on a larger 29er wheel.  If you don’t stay above those speeds and sustain them for long periods of time, or if you merely hovered around that speed, the charger actually draws more juice then it produces going in and out of charge mode, resulting in a net loss.  Bummer.

This probably works fine on a road tourer where you’re putting down miles at steady cadence, but this is supposed to be an off-road mountain touring bike, cruising fire roads under load, on inclines and dodgy ground.  Maintaining 11mph for any appreciable period of time on those kinds of roads is pretty difficult.  Your speed is always changing, always going up and down while you navigate this or that.  Sure you might get some flat or downhill stretches, but they go fast.  You invariably spend more time climbing then you do descending, and in that kind of terrain the charger was worse than useless.

I’m now convinced a solar panel is the only way to make this work.  I haven’t found a good one yet, but I’ve been looking at the Brunton Solaris 12.  Puts out 12v, 800ma, weighs 11oz, and  costs around $200~.

—

Anyhow that brings us up to speed.  That’s what I’m running and how I got there.  Lots of reading material if you’re interested.

PETER WHITE

Wouter

http://www.enhydralutris.de/Fahrrad/Goniometer/Tabelle_Scheinwerfer.html

http://www.enhydralutris.de/Fahrrad/Goniometer/AR2008/AR2008.html

http://sweetbike.org/downloads/light.dispersion.details.drilled.down.html

http://sweetbike.org/2011/11/28/2132

READ MORE ABOUT DYNAMO LIGHTS

READ MORE ABOUT DYNAMO HUBS

That’s it.

Onward.