Banzai

Last night I was riding, and my B&M light wired to an Alfine hub kept intermittently giving out and reverting to the stand-light, as if no current was reaching it. I think that maybe there was water in the connector causing this, but it brings up a real question:

Why continue to use this system when my Cygolite gives me no additional drag, and is also unaffected by water?

Thoughts?

Tourist in MSN

When I have electric problems, I first check to make sure that there are no loose connections. Does the connector on the hub fit snuggly? And are you using any quick connects at the light? I once was riding through a tunnel and could not figure out why my light was so dim, one of the connectors had come loose and all I had to see was the standlight.

Do you really feel drag from your hub? I can't feel any additional drag on my hubs, I often leave the light on instead of turning it off during daytime because the additional drag is imperceptible.

unterhausen

I have never had any problems with my dyno lights with a lot of abuse. The 20 hour ride in mostly heavy rain earlier this year comes to mind. I'm curious what is causing it in your case.

znomit

Because you will forget to charge the cygolite one day? Because every year the battery gives less runtime? Because the dyno light is usually more reliable? Because the beam is better?

unterhausen

With the Shimano-style connector, it's well worth occasionally taking the connector apart and re-twisting the wires and putting it back together. And if the wires are really bad, strip back a little and expose new wire and clip the ends.

I'm never going back to only using battery lights. I have been left without adequate lights too many times. Sometimes my fault, sometimes because I was out in the cold and the batteries just died prematurely.

Banzai

I'll take a look at the connectors, and hopefully that fixes it up.

angerdan

Would be also a good time to replace the old B&M light with a brighter model
The IQ-X delivers 100lx to the street surface:
bumm.de/en/products/dynamo-scheinwerfer/parent/164/produkt/164rtsndi-01-schwarz-164rtsndi-silber.html

unterhausen

please let us know. I always say I have never had trouble with my dyno lights, but I'm sure I have had trouble with the shimano connector once or twice.

Tourist in MSN

I have never had a problem with the Shimano or SP connector (SP is the same connector as the Shimano), but I use thicker wire than the standard B&M wire, thus it takes a bit more effort to push the connector onto and pull it off of the hub. I have heard others comment that their Shimano connector could fall off of the hub, presumably they used the B&M wire.

Several B&M lights have ways that water can get into the light on the underside. Generally that should not be a problem but if you had the light on a bike without a fender and the light is exposed to tire spray, that could be an issue.

unterhausen

I feel that you have to be somewhat obsessive about the way you prepare the wire when assembling shimano style connectors, and it's possible to dislodge the wire when it's off. Otherwise, the only problem I ever had with it was when I yanked the wheel off without disconnecting the wire.

Tourist in MSN

I mentioned above that I use a heavier gauge wire to my hub. My first dynohub wheel was used on three different forks. Thus, I bought some extra connectors and zip tied the wires to the fork, then I used quick connectors at the fork crown to connect my light and/or USB charging device. Thus, all three forks stayed wired even though only one fork had a dynohub in it at any one time. If I could have found lighter duty wire at the hardware store, I probably would have used it instead, I used the lightest wire they had. I do not recall the gauge number with certainty, but I think it was 18 gauge. My only problem is that the connector fits on it tight enough that I almost have to work to pull it off.

Since then I have accumulated more dynohubs, but I still wire them all the same way with a heavier gauge wire zip tied to the fork blade.



I mentioned above that one time a connector slipped off and I rode through a tunnel with just the standlight. The connector that slipped off was on my Luxos U.



At the time the photo was taken, no wired taillight, thus the wiring was simple.

My Luxos U mount is not a stock item, I used a different mount and did a lot of bending with a big vice and a big crescent wrench to make the bracket the shape in the photo. So, don't ask where I got it.

fietsbob

I had issues with a Shimano Dynohub Turned out it was a Grounding issue
not an output one. axle ground, rather than - lead from the headlight..

In the meantime I resolved it with a Schmidt Dyno hub..
The Shimano Plug had a habit of shaking loose with B&M twin lead wire ,
that never happens with Schmidt Spade type connector..




...

Banzai

Seems to be working ok now. The wire inside the connector looked a bit snarled and catywompus (technical terms), so I pulled it apart, clipped, twisted, and re-connected the little connector piece. I suppose multiple wheel removals might have done this, which I didn't expect. Kind of figured it would be set there until I chose to take it apart.

Ah well. Live and learn.

wschruba

Consider also applying some dielectric grease around the wires as they enter the connector--this will keep out crap, and keep the wires from oxidizing, leading to better, longer lasting connections.

unterhausen

I always forget about putting dielectric grease on mine. You can get it at auto parts stores

Tourist in MSN

I think all Shimano hubs are grounded to the fork, thus if you run two wires you have to make sure you have the correct wires in the connector at the hub if your headlamp is also grounded to the fork crown. There is a 50/50 chance you will get it wrong.

SP hubs are not grounded to the fork, thus you must run two wires with SP and it does not matter which wire is which in the hub connector.

I do not know about SON hubs.

Easiest wiring job I ever did in the photo, the light was designed for a sidewall generator, thus no switch so it is always on with a dynohub. Both the light and hub are grounded to the fork, thus only one wire was needed from the hub to the light. Battery taillight, so no wiring for that. I do not like the light this low, I get odd shadows from stuff on the ground, but for an errand bike for short distances it works great.

fietsbob

Mine was a Shimano - Brompton wheel , I got a Schmidt - new XS,
28 straight pull DB radial spokes ..
soldered the wiring ends, shrink tube covered the B&M wire , (Eyc SensoT)
crimped on the spade connectors , shrink tube over those..
spade connectors never came loose while riding , like the Shimano plug did.


Have 2 other Schmidt Hub wheels in 20 & 26" ..





....

rhm

I had a problem similar to what @Banzai describes. I was able to fix it short term by tightening the front Quick Release, but I solved it permanently the way @fietsbob did: I replaced the hub.
​​​​In my case I replaced a Shimano Alfine with a Shutter Precision.

The Shimano hub grounds through the axle, which I've found to be troublesome. I'm not sure why.

steelbikeguy

I've never looked at the Shimano hubs, but in general, making an electrical connection through plain steel surfaces is not a great practice.

For reference, I've worked in electronics my whole life, and have a fair bit of experience with electrical connectors. Connectors generally use a common metal as the core of the terminal/pin/socket/etc., and then add a plating over it. The plating provides a conductive surface that is not generally prone to oxidation.
Any oxide tends to be either an insulator or acts as a semiconductor that requires a certain level of voltage to be applied before electrical current can flow.

For this reason, I recommend avoiding using the frame as a conductor for the dynamo current. Granted, people seem to get tolerable results, but why use poor practices that invite trouble?

Just my thoughts, of course.

Steve in Peoria

unterhausen

using the frame as ground has worked for the entire history of dynos. Most older sidewall dynos didn't have a second connection, they had a grub screw that poked into the frame. Having a second ground connection shouldn't pose an issue with a power circuit. If it was low current, that would be a different thing entirely. BuM inexplicably had a current sensing circuit in the Luxos headlight which ignored the likely frame ground in their own taillights. But I think that was confined to that one light. With the Son connectorless dynohubs, they sell a couple of stainless pieces to add to the frame to keep corrosion from being a problem. But the fork is definitely grounded with those, no reasonable way to avoid it.

Having the frame grounded shouldn't be a problem unless one or both lights are also grounded to the frame and you hook things up backwards. Then everything would be grounded resulting in no light