Let There Be Light - Dynamo-Powered Bicycle Lights

1 year ago by Sebastian

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Cycling at night requires either owl’s sight or a very good set of lights. Unfortunately, I’m only human and my current setup consisted of cheap Decathlon rear light and Convoy S2+ flashlight. It was time to step up my game.

This post is a rewrite of previously published article in Polish. It also has been updated with my comments after over a year of use.

My usual setup wasn’t that bad, but it had one serious drawback - the batteries. The rear light wasn’t that bad. The built-in rechargable battery was holding up for decent several hours. Convoy S2+ however was a bit more problematic. It takes 18650 recharchable batteries and in the most powerful mode it lasted for one hour. I had to recharge them every ride and take some spares with me for longer rides. Also, it’s just a flashlight and it’s beam is far from being perfect for cycling.

Time for an upgrade…

For some time I’ve been dreaming about long bikepacking trips and with that, about some additional equipment. I’ve put some ridiculously expensive gear on my wish list, including SON dynamo hub and Sinewave Beacon front light. Despite my bikepacking enterprise being only wishful thinking, I decided to go on a shopping spree. After all, you can always buy stuff and have a proper use for it later.

I quickly realised that my wishlist has been at best unreasonable. I had to revise what’s in my financial reach. Instead of steeply priced SON hub, I decided to get cheaper Shimano Alfine DH-S501 (€90 instead ~€300), and for front light my choice was Busch+Muller Lumotec IQ-X (circa €90, not $350). There was also a technical aspect of my decisions, especially after reading this detailed analysis of various dynamo/light combos. It came to my understanding, that the budget Shimano hub is the next best choice after SON, especially if your light of choice is Busch+Muller lamp. To complement the set I also ordered Busch+Muller - Secula Plus rear light and some additional hardware, like connectors, heat-shinking tubes, cables, etc.

What’s with ze Germans!?

During my research, it appeared the most of the good stuff in terms of dynamo hubs and lights is produced by the Germans. Looks like cycling there is very popular and they have some harsh laws and regulations in terms of bicycle lights, therefor - high quality equipment.

There are some exceptions, but mostly in the category of dynamo-powered USB chargers. Some good stuff is produced in USA, Great Britain and Australia, but it’s mostly small, artisan companies with insanely high prices. The most insane price however was for the German charged, Forumslader, designed and sold on some niche German forum, with no obvious way to purchase it.

Let’s go!

I’m not gonna go into details of putting everything together, because it’s pretty simple and I’ve done it by myslef. The only part I was unable to do is building a wheen. I simply took a rim (DT Swiss 533D) and hub to a bike shop and they built it for me.

Dynamo hub has a simple, directional connector with 2 pins. One is for live wire, the other for ground. It’s a simple matter of connecting live wire to the lights and the other one can go to the frame or ground pin in the light.

For the future possibility of getting USB charger, I manufactured additional connectors for that purpose. Heat-shrinking tubes with solder made everything very easy and spared me from using soldering iron.

Then it was just a matter of putting everything on the bicycle. That I’ve found out to be a more difficult part.

I was going for hiding as much of the cables as possible. Thanks to my frame being a cheap one, the manufacturer was not so precise in boring holes for internal cable routing. There was some extra space and with great frustration I was finally able to tread dynamo cables through the frame and connect the lights.

On the front fork it was not possible to hide the cables, so I used some 3M cable guides from Jagwire to hold makeshift wire housing I’ve adopted from shifter cable housing.

I wrapped around excessive cable, because I didn’t want to cut it yet. It was possible I won’t be happy with the light placement and I didn’t want to redo the cables in the future. I wasn’t quite happy with standard front mount so I also ordered additional one from Supernova (also from Germany).

The Outcome!

Everything came together quite nicely.

Aestheticly, I’m very happy about how I managed to push the cables through the frame. My makeshift solution on the front fork also pleases me more than just plastic zip ties.

Functionally, it’s just perfect. There are no removable parts, no rechargable batteries. It’s always in place and on the moment you start pedalling. The mentioned article with hubs/lights analysis wasn’t misleading. Shimano hub is maybe not the best rolling one, but is indeed very cost-efficient. Around 20km/h front light is around maximum brightness. I was expecting good results, but I was still surprised how good it was even at lower speeds, like 10km/h. It’s feasible to go up the hill at night and still have a proper lightning.

Update: How is it after over a year in use?

The dynamo hub and lights have been doing really well. Despite the bike being very dirty most of the time, going through the rain, mud and snow, nothing has been going on wrong with any of the component. The dynamo is still rolling as smooth as dynamo hub can. The headlight has been the work horse guiding me through the nights. The only thing I’ve done with it, I’ve moved from the fork crown up to the bike computer mount. I was glad I left extra cable wrapped around the mount, it made the move painless. I had to buy some extra hardware thou, converting Busch+Muller mount to GoPro system.

The rear light, has been unfortunately a victim of my forest escapades. A stick launched by the rear wheel has bashed the housing and destroyed the transulcent part responsible for the light dispersion. I was unable to find the original housing and tried to repair it by other means, but in the end I replaced it with another light from same producer - [MY:], arguably the smallest light allowed by the German regulations.

All in all, I just couldn’t be more happy with my setup!

The list of parts and services (requested by the Wife🙈)

Hub: Shimano Alfine DH-S501 - €90
Rim: DT Swiss 533D - €25
Spokes and wheel building - €25
Front light: Busch+Muller IQ-X - €90
Rear light: Busch+Muller Secula Plus - €25
Cables, connectors, tubes: Allegro - €10-15
M3 Jagwire mounts: DCA056 - €10
Front light mount: Supernova Multimount - €20

Total: around €300

Update/Additional parts:

Replacement rear light: Busch+Muller [MY:] €50
Another front light mount: Busch+Muller GoPro adapter - €2


2023-10-10 15:15:49

Oświetlenie rowerowe w 2023 roku - Bobiko ▪ Blog --- […] Są też implementacje oparte o dynamo, co opisał Sebastian tutaj […]

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