Hot answers tagged

13

The main advantage, in my view, is that you can more easily add/remove battery-powered lights. Why this may be desirable: Theft resilience. I take my lights off the bike and carry them with me if I'm parking my bike outdoors for longer than a few minutes. Caveats: This can be more of a downside than a benefit, depending on your situation. (I can't imagine ...


11

Cheaper, easy to fit, more widely available - and don't take any effort! Probably most people's memory is of the side wheel dynamo systems when they were a kid that wore away tires, put out a feeble light and turned off when you stopped.


9

Some disc-brake specific wheels use rims that are not designed for rim brakes. To accomplish what you want you need a wheel with a a disc-brake hub and a rim-brake rim. With that setup, assuming the fork widths are the same, you should be able to switch wheels between bikes without problems. The only drawback is the slight increase in rotating mass from ...


8

i have been using the Supernova e3 Triple for night-time singletrack missions for the past two winters.....all I can say is awesome, completely awesome. 870 Lumens. bright. I used a Shimano Alfine dynamo hub and built a complete 'night wheel' with a DT 4.2d rim, it has rubber and a rotor mounted so swap-over time is very quick. We have months of mud, ice ...


8

Simple idea - turn the wheel over in the truing stand. The low side of the rim should move to the other side. If the Right-hand side is still low after flipping, your gauge is out and needs calibrating.


7

You should replace the rear wheel only if there is another well justified reason to do so, but generally both wheels are mostly independant, so you can perfectly change only the front. The first scenario I think of is where you are changing only the front hub (and spokes) and keeping the front rim. Why would you change the rear one? Easier task is to ...


7

When checking a Dynamo system, there are 3 basic items which need confirmation: Power Supply: Is your dynamo producing power? Checking this requires a multimeter, preferably with alligator clips on the wiring, and to spin the hub. Or there are specific tools, as well. Wiring continuity: Are all connections tight? Are there any breaks/shorts in the circuit?...


6

You might want to look at the Biologic ReeCharge by Dahon. It says it hooks up to any standard dynamo hub. The nice thing about this is that it has it's own battery. So the dynamo changes the internal battery and the battery charges your phone/gps/device. This allows you to change while you are resting, as well as provide added protection against sending ...


5

The easiest way would be to use a low-dropout voltage regulator. You SHOULD regulate the voltage to a stable 5 volts anyway, because you can hurt some electronics by providing them lower voltage than the expected 5. That being said, you can't just go get any old voltage regulator, because most have a dropout voltage of 2v - 2.5v above their target, meaning ...


5

Here's one option: http://h1987995.stratoserver.net/magento/supernova-the-plug-ii-plus-usb-dynamolader.html SUPERNOVA The Plug II Plus USB power supply Transforms dynamo AC to exact USB spec. DC 5V, 500 mA E‐Bike compatible for 12‐ 48V DC with optional cable Works with Garmin, Ipod&Iphone 3GS & 4G & 4GS Seems pretty expensive at €159, but ...


5

The common Shimano Dynamo hubs don't actually use sealed cartridge bearings, see the DH-3N71 and DH-3D72 techdocs. Shimano dynohubs do use good seals, however, and should hopefully be maintenance-free for many thousands of miles. Alistair Spence has a good exploded view of an Alfine DH-S500, which is very similar to the DH-3D71. He also links there to a ...


5

I have an Origin rear light and I've seen that it can be charged via usb and also have the lights on at the same time. If you want to have it powered by a Dynamo, what you could do is have the Dynamo connected to it the whole time on the bike and be lighting at the same time. That could be a way to pull it off and never have to take it off. Also, if you ...


5

Taking 100kg of bike plus rider up a 0.3% grade generates a retarding force of 100kg*g*0.003=3N. At 24 km/hr=20/3 m/s that is 20 watts. If that is generating 1A at 5V, the efficiency is 25%. Yes, I picked numbers that were easy to calculate with. But I believe this is all marketingspeak and you shouldn't trust the numbers to an order of magnitude. ...


4

Uh... Surprised why nobody's mentioned: 1) A dynamo-powered light changes intensity depending on speed (may not be an issue with modern LEDs which require low power); 2) No lights at all if you're stationary. This a serious disadvantage. If you have to stop in a dark area for whatever reason (puncture, something fell off the rear carrier), being seen is ...


4

Typically you need to purchase a light designed to work with a bicycle dynamo due to the power characteristics of a dynamo (lights need DC current). A well sorted hub dynamo (I personally have had great luck with Schmidt hubs) can produce up to about 6W of power depending on your speed and the design of the hub, which is a reasonable amount of power to work ...


4

Tyre driven dynamos can slip in rain or sleet. Hub dynamos can't slip, but do have a tiny amount of drag even when turned off. For a commuting bike, it's not enough to worry about, but on a high performance bike that you hardly ever use in the dark, with battery lights you don't have any drag from something you aren't using (and can leave them at home if you ...


4

I suspect you will find that most of the chargers that run off hub dynamos take this into account. For example, http://www.thinkbiologic.com/products/reecharge-power-pack in the (pdf) manual say: The ReeCharge is charging when the green light on the side of the ReeCharge is lit. NOTE: The green light is only on when the wheel rotates fast enough to ...


4

Well. I think that you really want this you have to build something youself. Basically you will need a light without a condensator and this circuit. Just add it to the power cable and have fun. http://www.instructables.com/id/LED-flashing-circuit/ IMHO flashing lights are not optimal because they reduce the ability to gauge distances. A better approach ...


4

I use this product: http://www.aliexpress.com/item/Spybike-Bike-GPS-Tracker-to-spy-and-pretect-your-bike-with-ease-New-bike-tail-light/32251529357.html Since this is a tail light, it is less suspicious as a GPS tracker. You can simply charge and remove the USB cable as well. (One thing to notice since this product is not inexpensive, I epoxied the screw ...


3

I found two seemingly solid options for dynamo powered lights suitable enough for night riding. However, I havn't had any personal experience with either, but both claim to be up for the task. SuperNova E3 Triple Exposure Lights Revo Dynamo Mk1 Both of these put out about 800 Lumens and offer a paired rear light which is chained through the front light, ...


3

Staying lit while totally stopped, for example at a junction, is a function of the light. It's definitely worthwhile, and a modern LED dynamo light with standlight function will give reasonable light for quite a while when stopped. Theft of dynamo lights seems to be rare, but if you are worried, consider using non-standard screws or bolts to make it harder ...


3

I have a Schmidt dynamo hub and it is "maintenance free". It uses sealed cartridge bearings so there is nothing to grease. The Shimano hub probably has a similar design?


3

Briefly: 1) yes, you can re-use the existing rim. 2) yes, you could shorten the existing spokes, but that would be expensive and foolish. 3) The installation is the same except now you have wires so you need to plug them into the hub too. The main issue is (2). Spokes are usually only reused when the rim is being replaced with an identical rim (usually a ...


3

A hub dynamo is typically rated at 6V/500mA, and most lights will use all of that. Modern LEDs give you a lot more light from that power, but it's still nowhere near as much as the high powered battery lights you can buy (so if the manufacturers could get more power into the lights they would probably offer it as an option). So the extra power you're ...


2

The Shimano hub dynamo bearings on one side probably not so difficult and you can look at their drawing but on the other side it can be difficult. I haven't tried to open the other side but you can check this out: http://www.bikeforums.net/archive/index.php/t-700163.html


2

The main point of failure, and in my opinion the largest disadvantage of dynamo vs battery lights, shared by both hub dynamos and side wheel dynamos is: wiring. The wiring on a bicycle is often very fragile, and in my experience it is always the first thing to break on any bike. This is especially true if you park in a bicycle parking area where your bike ...



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