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SON 29 S Creates Dynamo Hub So Tiny, It Disappears Behind Your Brake Rotor

SON 29 S sleek low-profile hub dynamo
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The bulbous dynamo hub is about to be a thing of the past, thanks to this sleek SON 29 S hub dynamo. With all-new narrow electronics inside, SON Nabendynamo tucked the dynamo generator into an enlarged flange behind the 6-bolt disc brake tabs that could be easily missed. With more performance all-road, gravel & adventure touring bikes with ever-expanding electronic gadgets these days, SON is making a better case for unlimited power on the go!

SON 29 S sleek low-profile hub dynamo

SON 29 S sleek low-profile hub dynamo, oversized flange
(Photos/Cory Benson)

Can I just start out saying that I am a big fan of dynamo hubs. Even if I don’t put in as many kms as I’d like, on the one gravel bike I have set up with a dynamo, at the moment. In a time where daytime running lights will keep me safer on the road, GPS mapping can lead me to discover new places to ride, my smartphone is an excellent mobile camera to share those rides, and derailleur batteries are quickly recharged via USB… the idea of self-sufficient power as I pedal is always enticing. I’ve had every type of electronic device die on a ride before. But never on my dynamo-equipped bike.

So now SON Nabendynamo has their first new hub dynamo in several years.

SON 29 S sleek low-profile hub dynamo hidden behind the disc brake rotor

The SON 29 S is a lower-profile hub with a new generator design tucked into an oversized disc-side hub flange, developed for the performance-oriented adventure market. On the bike, it almost disappears behind even a small disc brake rotor, giving you a more modern aesthetic.

Tech details

SON 29 S sleek low-profile hub dynamo, 6-bolt disc

The generator inside the SON 29 S dynamo hub may be narrow, but it is still designed to put out the same 6V/3W power as a regular dynamo. Like the 28, SON again optimized the 29 S for power output at relatively low speeds and 29″ wheel – outputting 6V from around 15km/hr (StVZO-compliant). According to SON, “together with smart charging electronics, it enables especially high power output” so you can not only power your lights but also recharge all of your gadgets once you are riding at a constant speed.

SON meant the 12mm thru-axle 6-bolt disc 29 S hub for road or gravel wheels, with straight-pull spokes. It features radially lacing on the driveside, and 2x on the disc side. The 29 S offers symmetric 32-hole drilling or 2:1 drilling for 24-spoke wheel builds, and comes only in black.

The new dynamo comes standard with SON’s easy-plug coaxial connector (like shown above).

SON SL Connect
(Photo/SON)

But it will also be possible to get one to work with SON’s self-connecting SL interface that integrates a powered ring directly into the dropout (like on this red fork that comes on Urwahn bikes). Then you don’t even need to unplug the dynamo to remove the front wheel.

SON 29 S dynamo – Pricing, options & availability

SON 29 S sleek low-profile hub dynamo, 12mm thru-axle with stright-pull spokes

Since the straight-pull hub design requires a bit more expertise to build up, at first SON is only offering the new SON 29 S dynamo hub in wheels built by them now in Germany. Complete front wheel builds start at 550€ with an alloy DT Swiss rim for road or gravel.

With that said, expect the new hub to also be available soon to reputable professional wheelbuilders for custom builds. And with its narrow design and 2:1 24-hole option, we expect to see a number of carbon road, all-road, and gravel wheels built up with the new SON 29 S hub dynamo in time for the start of next year’s adventure racing season.

New Ladelux LED dynamo headlight, too

SON 29 S sleek low-profile hub dynamo powers new smart Ladelux LED high-beam USB-chargin headlight

In addition to the innovative new dynamo hub, SON also has a smart new Ladelux dynamo-powered headlight, with low & high beams. SON designed the Ladelux for smooth output USB-charging of your electronics with a small internal buffer battery. And SON claims it is able to draw more power from a hub dynamo than any other charging device on the market (from 700c riding speed of >30km/hr) making it perfect for the adventure racer with lots of gadgets to keep juiced.

The 480€ Ladelux puts out 120/180Lux at any speed, backed by a 1200mAh battery inside, and includes a handlebar switch and magnetic charging cable for your smart device.

NabenDynamo.de

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21 Comments
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nooner
nooner
4 months ago

Slick, but that is not much light to be safe out on the roads. More like a “to be seen” light, not seeing where you are going at a high rate of speed.

Veganpotter
Veganpotter
4 months ago
Reply to  nooner

I’d be plenty happy riding a solid pace with 120lux and descending a mountain pass with 180.

nooner
nooner
4 months ago
Reply to  Veganpotter

How often do you ride over 50 mph? I do it practically everyday.

Veganpotter
Veganpotter
4 months ago
Reply to  nooner

Almost every day, but not every day at night. But I’d definitely feel comfortable hitting over 50 with 180lux

Tomi
Tomi
4 months ago
Reply to  nooner

People should ride according to the conditions. That is in pretty much every traffic law book all over the world.

So reduce your speed or mount an additional battery powered front light. That is what I do in the trail with a more powerful light on my helmet (that is not homologated for traffic use however). There is only so much power you can get from a dynamo.

Jam Ulrich
Jam Ulrich
4 months ago
Reply to  nooner

Really? The Edelux II is ‘only’ about 90 lux and that’s served many 1000s of distance racers, audaxers and tourers well for many years. The only time I’ve needed more light has been on sharp hairpins and that’s beam width not output levels. 120-180 lux range is huge amounts of light when it’s as well distributed as SON lights are. IME they’re lower output on paper than a torch-beam LED with whatever amount of lumens, yet more useable and useful light from them.

David
David
4 months ago
Reply to  Jam Ulrich

I’ve got an Edelux and it’s bright enough when nobody else is around and at moderate speed, but if I’m pressing on or there’s lots of traffic with modern LED lights I prefer to boost it with my Exposure Race

Dinger
Dinger
4 months ago
Reply to  nooner

I am reasonably certain you’re confusing “Lux” with “Lumens” which is easy enough to do. It’s too bad there isn’t a more universal standard (I find a great deal of variance in different lights of the same lumen rating). I have lots of hours on a 90lux Busch & Muller light. It’s about half as bright as a 1,000lm battery light I have but I can actually see farther down the road with it because it’s beam pattern is better. I’m perfectly comfortable descending at 30mph with it.

TypeVertigo
4 months ago
Reply to  nooner

Lux != lumens. You obviously haven’t been looking at too many dynamo-powered lights because very few of them use lumens for comparing output.

Lumens is measured at the source. Lux measures light projected on a surface. One lux = one lumen per square meter.

Craig
Craig
4 months ago

A shame there’s no standard flange 32 hole option. Maybe later on.

dan
dan
4 months ago

Whats the reasoning behind radial lacing on one side and no 28H option?

Balderdash
Balderdash
4 months ago

I’m still waiting for someone (other than Shimano) to make a dyno that can be serviced without unlacing the wheel. This design seems like it would be conducive to that, but after examining the pictures, it looks like the disc side flange needs to be removed before the hub can be disassembled.

MTB Biz
MTB Biz
4 months ago
Reply to  Balderdash

Been out for years
Kasai FS Dynacoil Dynamo hub

Balderdash
Balderdash
4 months ago
Reply to  MTB Biz

Can’t believe I missed those. I’ll definitely be using one for my next dyno wheel build.

Tamir72
Tamir72
4 months ago
Reply to  Balderdash

Balderdash, please note, the Kasai FS (Field Serviceable) is not really “Field” serviceable, the inner bearing is in the middle of the armature and not easy to remove / replace while out in the field, the company expect the owner to buy a spare armature and carry it along with a 36mm spanner should the owner need to service the hub in “Field”, also they state that the hubs are not waterproof and advise against submersion.

Roy Keen
Roy Keen
4 months ago
Reply to  Balderdash

I serviced my Taiwan-made dynamo, it’s not quick job but it’s doable if you have reasonable wheel trueing skills to rebuild one side of the wheel (leave the non-disc side laced so the hub can be separated using the brake mounts as leverage).

Balderdash
Balderdash
4 months ago
Reply to  Roy Keen

I serviced my SP dyno as well. The problem is that by making it impossible to service the bearings of a hub without unlacing half the wheel, they’ve made it a much more irritating and time consuming process than if I were able to service the bearings of the hub *without* unlacing half the wheel. Considering that Simano and Kasai make hubs that can be serviced without unlacing half the wheel they are built into, buying anything else seems like a tough sell to me.

Gabe
Gabe
4 months ago

Cory, did they post a claimed weight or weight savings vs the 28? Thanks!

threeringcircus
threeringcircus
4 months ago

Is there more to the SON 29 than just making it look more like a “normal” hub? I’d consider it for my next dyno wheel if there is a notable weight savings or functional improvement, but otherwise working with straight-pull spokes isn’t an attractive tradeoff.

AhmedAzli
AhmedAzli
2 months ago

I read somewhere that it is a bit stronger and a bit lighter. Won’t be noticeable for trekking rider, but rather for weight weenies

J Epstein
J Epstein
23 days ago
Reply to  AhmedAzli

It’s engineered for 29” wheels which spin somewhat less to cover the same distance. That requires a more powerful generator to develop the same wattage with fewer rotations.

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