Dynamo setup questions.

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Milkfloat

An Peanut
Location
Midlands
I figured it is getting close to the right time of year for all the lighting questions, so I would start one off.

I am finally going to move over to an inexpensive dynamo setup, although I might run some battery lights as well when I go out into the countryside. My main use is daily commuting, although I will also also use the bike for popping to town/scouts where it will be left outside. I have priced up the following:

upload_2019-9-17_13-47-8.png


The wheel is https://www.bike-discount.de/en/buy...shimano-dh-3d32-with-mavic-xm-119-disc-510868
The front light https://www.bike-discount.de/en/buy/rfr-dynamo-tour-70-front-light-822245
The rear light https://www.bike-discount.de/en/buy/rfr-dynamo-tour-rear-carrier-light-822249

Question time:
1.) Is the DH-3D hub pants or is it ok?
2.) Anyone know how this will wire up? I assume the front light has a 'tail' coming out of it that I can join with solder and route to the rear and then use some spade fittings to connect?
3.) Can anyone think of a different budget option, ideally giving me a front light that allows me to see as well as be seen?
 
I cant help with the technicalities but that is far cheaper than I imagined.
 

Dogtrousers

Kilometre nibbler
Re (2). A couple of years ago I put a similar set up on my bike. It was really frustrating that there were no instructions but I finally figured it out. Here's a picture I did at the time.

upload_2019-9-17_14-50-44.png


A month or so later I took it all off because the front lamp was faulty. I got a replacement but I've never got around to putting it all back on again.

Hope this is of some use.
 
https://www.rfr-bikeparts.eu/en/rfr...ct/rfr-front-light-dynamo-tour-70-blackngrey/

The front lamp is bright enough to light up the road and German enough to concentrate the light where you need it.
My front lamp has spade connectors for power in and power out. My rackmount Smart light has spade connectors. Some lamps have spring loaded tabs with a hole for the wire.
Shimano dynohubs are all good. The better grade ones are a bit more efficient.
Rotate the hub wire connector to the bottom to drain water. Coat metal in vaseline for better connection.
The wire routing you generally have to figure out yourself but keep enough slack for rotation and accidentally snagging. Reinforced the wire with ducktape in exposed areas Gorilla tape seems to be the best current version.
I run my wire along the rear brake outer then along the rack, down on top of the rear mudguard then up to the rear lamp.
 
Location
Loch side.
I figured it is getting close to the right time of year for all the lighting questions, so I would start one off.

I am finally going to move over to an inexpensive dynamo setup, although I might run some battery lights as well when I go out into the countryside. My main use is daily commuting, although I will also also use the bike for popping to town/scouts where it will be left outside. I have priced up the following:

View attachment 485564

The wheel is https://www.bike-discount.de/en/buy...shimano-dh-3d32-with-mavic-xm-119-disc-510868
The front light https://www.bike-discount.de/en/buy/rfr-dynamo-tour-70-front-light-822245
The rear light https://www.bike-discount.de/en/buy/rfr-dynamo-tour-rear-carrier-light-822249

Question time:
1.) Is the DH-3D hub pants or is it ok?
2.) Anyone know how this will wire up? I assume the front light has a 'tail' coming out of it that I can join with solder and route to the rear and then use some spade fittings to connect?
3.) Can anyone think of a different budget option, ideally giving me a front light that allows me to see as well as be seen?

Don't go cheaper on the light and dynamo. 3W is the minimum you want for a dynamo and those German-approved lights are the best. They are really bright and have some nifty features.

The light unit will have four wires. Two for the rear light and two for input from the dynamo. The dynamo produces AC and the light unit supplies DC to the rear light if I remember correctly.

My advice is to find a light without a rear light set-up. Use a standard battery rear light. Find one that uses AAs, instead of AAAs. Reason being that the wire routing to the back is ugly, fiddly and awkward. I disabled my rear light wire and closed up the hole with tape.

The hub you chose is fine. There is one caveat though. It has an aluminium coil which apparently saves some weight, however, it has one massive drawback. When servicing the bearings it is very easy to damage the insulation on the wires from the coil and short it out against the axle. The wire runs in a lot in the axle and the nuts easily damage the insulation when you remove it to get to the cones. When that happens, you are screwed because you cannot solder another piece of wire on there 'cause of the alu coil. Just keep it in mind when you service the hub and be super careful.

It will be the best move you've ever made. The light is bright and the beam pattern excellent. You won't need other lights unless you are doing night riding on a MTB, then you want a helmet light as well, (yes, yes, I know) so that you can see where you want to go, not where the bike is now pointing.

My light is always on and even in daylight people comment on how bright it is.

My light is a Supernova but the hub is the same as yours. Exactly the same is going onto a new bike I'm now building.
 

Dogtrousers

Kilometre nibbler
My advice is to find a light without a rear light set-up. Use a standard battery rear light. Find one that uses AAs, instead of AAAs. Reason being that the wire routing to the back is ugly, fiddly and awkward. I disabled my rear light wire and closed up the hole with tape.
If you want a 2x AA powered rear light with rack fit, here's what I use which is V good. Batteries last +/- for ever.
https://www.sjscycles.co.uk/lightin...ent-battery-led-light-50-80-mm-vario-fitting/

If I ever get around to refitting my dynohub front wheel/light I won't bother with the rear one.
 

palinurus

Velo, boulot, dodo
Location
Watford
My advice is to find a light without a rear light set-up. Use a standard battery rear light..

I think this is probably the most popular method- and currently I'm doing it myself- but I do miss having a rear dynamo-powered light. I liked that I could get my bike out at any time without having to go looking for a blinky (invariably I run them on multiple bikes) or needing to charge something.
 

Ming the Merciless

There is no mercy
Location
Inside my skull
The bare wires from the front light wrap round the Lego brick connector. There is a diagram of this in the booklet comes with it. Then you click the Lego block on to a matching part of the Dynamo. When removing wheel for punctures, you'll want to disconnect the Lego brick.

Agree about rear Dynamo lights. I have them but the wire routing is not so today. Rear LED lights last so long that battery ones are fine.
 

cosmicbike

Perhaps This One.....
Moderator
Location
Egham
I have the same dynamo on my CX, fitted last year as I was fed up with charging batteries. Not had any issues so far. Front light is a B+M Lumotec of some description, and the rear a TopLight Line Plus.
Cabling from front to rear depends on how tidy you want your bike. Mine is very much a commuter, so I have simply wrapped it around the top tube then along the rack to the light. I also run a flashing LED rear (battery powered) on the dark mornings.
 

andrew_s

Legendary Member
Location
Gloucester
The light has 2 short wires with spade connectors on the end, for the rear light, and a long wire for the hub.
The German convention is that the all-black wire is live, and the back&white wire is earth. Whether this matters or not depends on whether the lights and dynamo are electrically connected to the bike via the mounts & QR, but it's easiest to just assume there are frame mounts and follow the convention about which wire goes to which connector. In the case of the dynohub, it will be obvious whether one side of the terminal is connected to the QR if you look at it with the plastic block off.
I prefer a dynamo rear light, as it switches using the front light switch (or senso), so there's no need to stop to light up (reaching the switch on a rear of the rack battery light is enough of a stretch that you could lose control of the bike if you try without stopping - BTDTGTTS). In addition, checking a battery light brightness when you turn it on can be misleading as the batteries are rested, and it's quite possible for a rear light that looked OK be be pretty dim 10 minutes later.

Shimano dynamo hubs are officially not serviceable, as it's easy to break the very thin wires taking the power out past the cup & cone bearings via a slot in the axle.
Despite that, it's best to do a partial service on a hub when it's new, as they commonly come with the bearings set too tight, and not enough grease, which can lead to short life.
If you remove or loosen the cone from the brake side, and push the axle across, it's often possible to open up enough of a gap past the seals to inject some extra grease using a grease gun and thin squash tubing. If you can, do so, then grease the brake side and adjust the bearings properly, so that there's a little play with the QR undone or loose, which just disappears when you tighten the QR properly.
 
OP
OP
Milkfloat

Milkfloat

An Peanut
Location
Midlands
Just a follow up - the parts arrived from Germany within 48 hours and were fitted that evening. I have the battery rear on at the moment as I have not found my stash of speaker wire. The light seems to flicker slightly even at 20 mph, the capacitor seems to be taking power as the light stays on for a few minutes when I stop. I really want to have both lights 'fully automatic' so I will track down some cable this weekend. On a plus note, the front light is fine to see with.
 
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