Cycling UK Forum

Wiring it is a doodle.
The SP hub has its own Connector, the B&M do come with all the wiring and spade connectors. Better to solder the ends of the wiring to the rear light, and use the heatshrink sleeve, but make sure you cut to right size first, in doubt leave a good inch or two more
My favourite routing for the rear light is using some pvc sleeve, along the wire run for the front derailleur, when this goes by the down-tube of the frame. I use a 4-5mm ID plastic sleeve (pvc one that you can find for cheap in Maplin) and feed the light wire, then the front derailleur wire. The tension of the derailleur wire keeps the pvc sleeve in place, so no zipties are required there!

Thanks Gatteronero, I think I know what you mean with the ID sleeves. These clip round sort of doing the same job as a zip tie, and about the same width.
Just a slightly naive question, when I tried to spin the hub, it was very stiff,( I have never had a dynamo hub before), is this normal?
Thinking about this, is it due to the magnet stopping the spinning of the wheel? This would make sense to me.

Many thanks

Martin

Yep generator hubs feel stiff because of the push and the pull of the generator, even if the overall resistance turns out be low.

yup, the acid test is when you have built the wheel, installed it, and you spin it. It'll vary with the rim and tyre weight, but a nice hub generator ought to allow the wheel to spin (after a single push by hand in the spokes) for 10-15 seconds or so (lights off). This normally corresponds with a drag of 1-2W or so.

cheers

Well, Had a day off and managed to fit the wheel and lights.

Generally very pleased with how it went, ie I didn't break anything, or cause myself a significant amount of blood loss!

I wound the Cable between the front light and the dynamo around the fork blade, and just used a single cable tie at the bottom.

the Rear light I used cable spiral wrap to fix the cable to the Brake outer along the top tube,

The front light has a stand light function and can be switched off, so there is a small amount of power stored when you come ot use the bike again, other wise there are a few mins where if you stop the light goes out.
The rear light, also has a stand light, but has as far as I can see, and there are no instructions included with the light, have an on/ off switch, so the light will be on all the time.

Not used it for real yet, thought today was a little frosty to risk it, (Just rode the single speed instead)

( the wheel came from SPA, who I would defiantly recommend, both from service and build)

Martin

Update,

Mods do you think it's worth merging the three recent threads about dynamos and charging devices?

So have used the dynamo for the lights, this works well.

But using the e werk with the mio whilst switched on is a lost cause! This might be a mio issue and it would work well with a Garmin but......
Essentially it looks like it's charging, but it still ran out of power. It boots back up again and if you don't open the recording screen, it seems to be able to keep going, but don't stop!. This might be how the e werk charges a device.
Even with the lights off, and the device on the power still drops at the rate that I would expect it to.

So going to try a different device and see what happens.

Martin

It's worth experimenting with main USB and turning the power off and on at the socket to find out what's going on with your devices.
Some devices are either charging or in use, and won't do both.
Some devices won't restart charging if they lose USB power briefly.

For example, Garmins are known to turn themselves off after a brief loss of external power unless you tell them to continue on batteries quickly enough (within 15 sec or so of losing power).

Because of problems, it's fairly common to charge a USB battery during the day, and use it to charge your devices over the evening.
However, doing this carries an efficiency hit that means that if you have high power requirements (eg a tablet), you are more likely to have trouble doing enough dynamo charging to keep up with your power use.
Battery packs can also help with the fact that USB plugs/ports are not weatherproof and not very robust when there's a vibrating cable attached. It's generally cheaper to replace a modestly sized USB battery if the port fails that it would be to deal with a dead port on a phone.

andrew_s wrote:...

Because of problems, it's fairly common to charge a USB battery during the day, and use it to charge your devices over the evening.
However, doing this carries an efficiency hit that means that if you have high power requirements (eg a tablet), you are more likely to have trouble doing enough dynamo charging to keep up with your power use.
Battery packs can also help with the fact that USB plugs/ports are not weatherproof and not very robust when there's a vibrating cable attached. It's generally cheaper to replace a modestly sized USB battery if the port fails that it would be to deal with a dead port on a phone.

Agree with that. I had a Lezyne light failure while charging daytime on off-road.
That's why I suggested to charge a powerbank during the day, and use it to recharge the electronics at night: those devices should not left be in the cold anyway, so you may as well leave them on charge, since they are safe in a bag inside the tent (or, better, your sleeping bag)

Ok have tried an alternative charger with the mio and it's still does not appear to charge.
So I have a couple of thoughts. When charging the unit switched on at home, using a dedicated charger, the unit definitely charged whilst switched on. So is the problem possibly the cable I am now using? This is cable that does both data and power transfer, is it possible to get a USB to mini USB which only does power?
Alternatively the unit may not be able to charge and run at the same time, but it did seem able to do this when connected to a mains charger

martinn wrote:...is it possible to get a USB to mini USB which only does power?

Yes - the cables supplied with many USB rechargeable devices are such (as I realised some years back when I couldn't transfer files from my phone to PC using an odd USB-mini USB I had lying around )

Ok this is quietly driving me nuts!
Tried a "dumb" USB cable no difference.
Tried light on / lights off no difference

As an experiment I tried it plugged into the cigarette lighter socket of the car, and it worked, fully charged whilst mapping.

So the issue is not the unit will not charge whilst on, nor the cable
Therefore it must be to do with the incoming current.
My thought was that as I vary the speed, the charged produced by the dynamo will vary.
If the MIO needs a very stable charge current, then I need to stabilise the incoming current to it.( Some Garmin's apparently work quite happily with a variable current.)
So if I charge the GPS via a power bank, this should give a stable current and thus charge the device.
If I get a pass through power bank, I should be able to charge the power bank and the power bank should be able to charge the GPS
Does this sound sensible to those who understand this sort of thing!
Alternatively, I will go and get a Garmin, which is probably what I should have done in the first place

Martin

[summary of posts elsewhere]
USB was originally designed to power keyboards, mice, external dis[ck]s etc, and consequently some USB ports, such as those on old laptops, won't supply much over 100 mA. When you plug your device into a USB port, it has to decide whether the port is on an old laptop, or whether it's on mains and will happily give a couple of amps. It will do that by asking for 100 mA and checking the voltage drop, then stepping up the current and checking the voltage again, until it's found the highest current that doesn't give a voltage drop, which it will generally stick with, without checking again.
If it decides that the charge limit is only 100mA before you've really got moving, and sticks with it, you'll never get your device charged adequately. Some dynohub chargers won't give any power at all for the first 5 or 10 seconds to avoid this

Thanks for the reply Andrew,the dynohub charger that I am running is one of those that waits for 10_20 seconds until connecting. Am i simply not moving fast enough quickly enough?? I average around16-18 mph on a normal ride/ commute.

Would an inline switch help? Ie turn on the power connection only when I am moving.
Thoughts anyone

Martin
( This is sort of like turning into my "mole")

Right phase 3 worked.
This involved using a pass through power bank, connected to the charger. However I did note that even when I had disconnected the charger, my lights(dynamo powered as well) were still dimmer. So I was thinking if I put a switch between the charger and the dynamo, I should be able to switch it off when I need the lights full power.
Does anyone have a recommendation for a switch, I have done some looking, but they all seem a bit big.

Martin