Commuting - Lumotec and similiar lighting vs. battery lighting

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d2create
10-18-05, 07:37 AM
Can someone please explain how these european style lumotec and other lights work where they are wired to the rear hub? I think some Breezer bikes come with them and I've seen them mounted on touring bikes. How do they work? How do they compare to lights like cateye that work off AA batteries or the more powerful lights that work off battery packs? What about cost and installation effort?

Thanks!


ajay677
10-18-05, 08:05 AM
These lights run off a generator hub. Mine is a Schmidt Sohn front hub. My Lumotech headlight uses a 2.4 watt halogen bulb, while a 0.6 watt tail light uses the remainder of the 3 watt current generated by the hub. There is practically no discernable drag from the hub when the light is in use. The difference with the Lumotech style of light is it's reliance on a precisely focussed beam of light with extremetly high quality optic components. It puts the light on the road in a narrow beam precisely where you need it for riding. It doesn't waste light by throwing it to all sides and to the heavens like the more powerful lights available. That said, it is not suitable for off road riding (mountain biking) because of this. You can also outrun your light on steep downhills. Many people use two lights just for the downhills, one focussed further ahead. All in all the system I have is extremely durable and convenient. It fits the bill exactly for the fair weather commuting and randonneuring that I use it for.

royalflash
10-18-05, 08:06 AM
Can someone please explain how these european style lumotec and other lights work where they are wired to the rear hub? I think some Breezer bikes come with them and I've seen them mounted on touring bikes. How do they work? How do they compare to lights like cateye that work off AA batteries or the more powerful lights that work off battery packs? What about cost and installation effort?

Thanks!


They are usually wired to a dynamo that rubs on the rear tyre or to a hub dynamo that is usually mounted on the front wheel. Obvious advantages - no batteries required. Changing batteries in modern lights is often almost impossible at the road side in the dark. Hence, you need to keep your batteries charged and preferably have two sets of lights so you can swap them over when the battery runs out. Disadvantage- more rolling resistance/dynamo can slip when wet but this can be mainly overcome by using a hub dynamo (SON are the best but not cheap)

I would say that the Lumotech are not as bright as many LED/battery pack type lights but the best solution is to use both and combine the advantages of both types.

You can also get Lumotech lights that automatically switch on when it gets dark which is a nice feature.


markf
10-18-05, 09:25 AM
Can someone please explain how these european style lumotec and other lights work where they are wired to the rear hub? I think some Breezer bikes come with them and I've seen them mounted on touring bikes. How do they work? How do they compare to lights like cateye that work off AA batteries or the more powerful lights that work off battery packs? What about cost and installation effort?

Thanks!
My Lumotec light runs off a Shimano hub generator, built into the front wheel of my bike. The light bolts into the hole in the fork crown, it shares the front fender mounting bolt. I can switch the light on / off or there's a sensor on the light that turns it on automatically when it gets dark. The main bulb is a halogen bulb, then there's a LED that runs off of the charge stored in a capacitor, so that cars can see me when I'm stopped at a traffic light. The LED is called a standlight.

My light works better than any Cateye, etc. running off of AA cells, I can see far enough ahead to ride 20 mph on an unlit road or bike path. It puts out usable light at just about any speed over 6-8 mph, and it's designed so that the bulb won't blow out at high speeds. It's not nearly as powerful as the battery pack lights, but the beam is very tightly focussed so it reaches a long way. The battery pack lights offer a wider beam and keep working no matter how slowly you go, both of which are good for off road riding. Good battery pack lights cost about as much as good hub generator lights.

There are still generators that run off the tire sidewall, these are easy to install but they slip when the tire is wet, and they can trash your tire sidewall if you don't adjust them right.

Shimano sells two hub dynamos in this country, the Nexus NX-30 and the DH-3N70. The NX-30 is comparable in quality to entry level Shimano components, so it's good value for the money, about $30. The DH-3N70 is about $90, the bearings and seals are comparable to Ultegra or Deore XT hubs, it's lighter and has less drag than the NX-30. Schmidt (German company) offers the Schmidt Original Nabendynamo for about $210. It's a beautiful piece of work, lighter and smoother running than either Shimano hub, and there's no generator drag when the lights are switched off.

Lights for these hubs are $40-$120, you get better optics (tighter beam) and things like a standlight as you spend more money. Hardcore long distance riders will sometimes wire two headlights into a system with a Schmidt or DH-3N70, but one light is plenty for most commuters.

The big hassle with a hub generator is that you have to build it into the front wheel, so you've got the expense of a new front wheel. Once that's done you've got a really good easy to use system. No batteries to charge, no tires wearing out from misadjusted sidewall generators, etc.

Check out www.peterwhitecycles.com (http://www.peterwhitecycles.com) for more about the Schmidt and Shimano dynamo hubs.

GTcommuter
10-18-05, 09:34 AM
Good timing on this question. I just completed my second week of running a Shimano NX-30 hub and Lumotec Oval headlight. Just in time for shorter days. I was fortunate to get the entire system ready to use from a guy that bought a new Cannondale commuter and didn't want to mess with a generator hub. The price and my own curiousity sealed the deal. I like the light much better than my small Cateye Opticube, which was sufficient for lit streets but not nearly enough for true night time commuting. The Lumotec is very bright and like people say, puts the light right where you need it. The hub resistance was notible at first, but I just consider it resistance training and I'm already back to my normal commuting times. I've also gotten lots of complements on my "serious commuter." The whole system might get transfered over to my project town/comfort bike so that I can get my XC back to a fast commuter, but that will be in the future. Anyway, I've been very happy with the system and haven't had one battery-related to deal with.

MichaelW
10-18-05, 10:30 AM
I use a lumotec powered by a rechargeable SLA 6v battery in a waterbottle. It was an easy system to buildup and provides the same light output as a generator but works at full power when Im not moving. Hella is another good manufacturer of lamp units. Their FF unit is very compact.
My touring bike has bottle generator for emergency use. The modern Nordlight dynamo is boltd to tab on the frame rather than a seatstay clamp. They are not as effective as hub dynamos but offer zero drag when not in use. Slippage depends on the choice of tyre, roller and mounting accuracy. Mine works OK.

cedo
10-18-05, 11:41 AM
On my randonneur /touring bike with an SON generator, I run the Lumotech with a secondary Schmidt light. This is an exceptional system. On occasion, other riders have done a double take when looking back, thinking that I am a car.
One other disadvantage - on as steep uphill, the lights dim dramatically. Of course you're not going very fast, but it can be disconcerting.

d2create
10-18-05, 12:14 PM
Thanks for the replies so far...

I have a lot of stops on my 12 mile route. 20 stop signs and 20 trafffic lights. I don't stop at all the stop signs and many of the lights are green when i get to them. But i still have to slow down or come to a complete stop more than I would like. And I'm not concerned with seeing since my current route is lit enough most of the time, I'm more concerned with BEING seen by motorists. Will these circumstances make my choice on which way to go any different?

fsor
10-18-05, 01:46 PM
If you have the coin, there is a lamp unit built for the SON and Shimano dynamos that has an internal LED fed froma capacitor that charges while you spin....It stays lit for 3 minutes or so after you stop to let you be seen and for map reading.

Michel Gagnon
10-18-05, 06:20 PM
I concur with markf and others on the subject. My commuter has a Shimano NX-30 and my tourer a Schmidt. Both are great, and they aren't that expensive if you want to develop your wheelbuilding skills at the same time. I built my wheels using Sheldon Brown's wheelbuilding page (http://sheldonbrown.com/wheelbuild.html), and I have two 3 year old wheels that never needed any truing whatsoever (I built them in the fork, without a truing stand).

I use a 3 W headlight and no wiring along the frame because I use battery taillights. As a bonus, my system is more flexible and works whether I cycle by myself, or with the trailercycle or the child/cargo trailer.

As for d2create whose commute has a few stops, there are a few options, depending on the likelihood of potential conflicts with opposing traffic who might turn through you:
– Use a Lumotec Oval Plus (http://peterwhitecycles.com/schmidt-lumotec.asp), which has a standlight. I think the standlight is minimalist: good in the dark, but not when you compete with many other light sources.
– Use a small white (or amber) LED light that uses 2 AA or AAA batteries. The Cateye EL-400 or the BLT SuperDoppler are two good examples of tiny headlights that are quite visible when stopped or when climbing a steep hill, and that could be used in flashing mode if necessary.

PaulH
10-18-05, 06:43 PM
I use the B&M LED rear taillight with capacitor. It gives a good glow for several minutes. The lack of a headlight when not moving is no problem for me. If you are in an area with few or no streetlights, the Standlight is a good option. You can go with either a sidewall dynamo or a hub dynamo. The hub dynamo requires wheelbuilding, but is much more efficient, quieter, and unaffected by rain and snow. Installation is easy once the dynamo has been built into the wheel.

Paul

slvoid
10-18-05, 08:41 PM
How does the light compare to say a 10 watt halogen?
Also, is there a built in reserve for when you slow down but still want to be visible?

carless
10-18-05, 09:30 PM
How does the light compare to say a 10 watt halogen?
Also, is there a built in reserve for when you slow down but still want to be visible?
<observation> thats a spooky avatar-pic thing. looks like Billy Madison w/ Jack Nicholson eyebrows in a very bad clinic <observation>
I like my HID lights that astound people with their brightness. It's basically a car headlight with the weird responsibility of aiming it to not intentionally blind everyone. I have looked at dynamos and can't understand the comparisons, the electronic schema's and I don't like the no-off-the-shelf options. Is this enough light to see, or just enough to meet randonee type rules. Is this a cost effective daytime running light or a single source eccentric tempermental DIY project. I'd like to see a simple comparison of how bright these hub lights are.

ollo_ollo
10-18-05, 09:53 PM
I have 4 winter bikes set up with different dynamos: 3 have halogen headlights driven by: an old Union generator that runs on the sidewall, a Soubitez bottom bracket generator & a Sanyo bottom bracket generator (both of which run off the rear tire tread) and one bike runs a LumoTec headlight off a Sturmey Archer DynoHub. The LumoTec has overvoltage protection & a capacitor that accumulates enough charge to run a white led for 3 or 4 minutes when stopped. All of these systems produce 6 volts 3 watts as long as you are moving & the only difference I note is a very slight resistance with the generator systems. I don't notice any resistance with the DynoHub and the light produced by each system is quite similar, yielding a rectangular pattern of light that is adequate on city streets but about what you would expect from 3 watts on a dark country road so I use a vistalight 10 watt or 15 watt running off a SLA battery on that stretch of my commute. I have ridden side by side with a friend who has a Schmid hub & the same LumoTec headlight. It is hard to see a difference in the light output but the old DynoHub is steel, heavy & there haven't been spare parts available for about 25 years or so.

ollo_ollo
10-18-05, 10:10 PM
The hub driven Lights are definitely bright enough to see by but I'm not comfortable at higher speeds (above 16-18 mph) on dark country roads. They can be left on to run during daylight or set to come on only when its dark. They aren't eccentric, temperamental or a DIY project, just pretty basic. Seem to run for years trouble free as far as I can tell. For DIY light projects, see the Total Geekiness thread. Some of those systems are very impressive.

MichaelW
10-19-05, 03:34 AM
I used to ride sections of trail through an unlight park every night in winter at a speed of about 15mph. The 3w Lumotec was quite adaquate for the task even on moonless nights and in the rain. You cant ride high speed on trail which is new to you, but if its your regular route you probably know every bump blindfold.

LóFarkas
10-19-05, 03:53 AM
I have a lot of stops on my 12 mile route. 20 stop signs and 20 trafffic lights. I don't stop at all the stop signs and many of the lights are green when i get to them. But i still have to slow down or come to a complete stop more than I would like. And I'm not concerned with seeing since my current route is lit enough most of the time, I'm more concerned with BEING seen by motorists. Will these circumstances make my choice on which way to go any different?


Put 1 red LED blinky on the seatpost that works 50+hours on AA's, prferably rechargeable, and one white on the handlebar. Takes ten minutes and $30 to buy and install. Minimal weight, 5 min to switch over to another bike if needed.