Schmidt's Original Nabendynamo
 

The Schmidt Dynamo front hub or SON (Schmidt's Original Nabendynamo) is extremely reliable and has almost no drag. Made by Wilfried Schmidt Maschinenbau in Tübingen, Germany, the hub is quiet and is designed to give at least 50,000 kilometers of trouble free riding between servicings.  The hub powers many different six volt headlights including Schmidt's own Edelux II LED headlight and assorted taillights, both older halogen and LED headlamps and taillights made by Busch & Müller in Meinerzhagen, Germany, plus Supernova and Spanninga lights.

Many cyclists want to charge a cell phone or GPS while they ride. The SON hubs are ideal for keeping your GPS going. We have several AC to DC converters for this purpose.

When your bicycle can make its own light, it becomes a reliable means of transportation, not just a toy or play thing for an afternoon's entertainment or exercise. With an automobile, you take its lights for granted. You get in the car, turn on a switch, and drive on down the road with the light you need. With the SON, you can take quality lighting on your bicycle for granted, just as you do in a car, making your bicycle just as convenient to use for everyday transportation as an automobile.

SON dynamo hubs have a five year warrantee.

We stock versions for bikes with rim brakes as well as disc brakes; both Centerlock and ISO. We have versions for folding bikes with short front hub axles, versions for 12mm thru-axle, 15mm thru-axle, 15mm boost, tadpole type trikes, and even for "fat bikes" with their 135mm axles, and the really wide 150mm thru-axle forks from Rock Shox.

"SL" hubs use a special axle, and require a specially constructed fork to function. See all of the details on the SL hubs on this page.

 

SONdelux Wide Body
     

chainring

The SONdelux Wide Body gives you the lowest drag possible while also giving you the strongest wheel, due to the wide flange spacing. The standard SONdelux (see below) has flanges 50mm apart. The SONdelux Wide Body has the flanges 68mm apart. It's just a bit wider than the new SON28, and looks pretty much the same. Should you take a little tumble, the wider flange spacing will help the wheel resist warping due to high side loading since the wider flange spacing will maximize the lateral stability of the wheel. Also, heavier riders will be able to set their brake pads a bit closer to the rim since the rim won't flex sideways as much while climbing out of the saddle.
If you want the lightest dynamo hub, get the standard SONdelux with 50mm spaced flanges, below. But if you want the most stable wheel possible and don't mind the slight added weight (about 24 grams) and cost, get the SONdelux Wide Body with 68mm spaced flanges. That's what I use on my road bike. I weigh 165 lbs and use the 32 hole with a Mavic Open Pro rim. The SONdelux Wide Body is available in 28, 32 and 36 hole drilling, polished, 32 hole in black, and for rim brakes only. There is no disc version. But with disc brakes, if the rim is flexing laterally while your climbing, it doesn't matter since that doesn't affect the brakes.
Polished
     
SCH262808 SONdelux wide body, Polished, 28 hole $323.00
SCH263208 SONdelux wide body, Polished, 32 hole $323.00
SCH263608 SONdelux wide body, Polished, 36 hole $323.00
Black Anodized
     
SCH263218 SONdelux wide body, Black Anodized, 32 hole $323.00
     
   

 

SON 28
     

chainring

     
The SON 28 is available in polished (as shown) Silver Anodized, Black Anodized, Red Anodized, and Blue Anodized; 32 and 36 hole drillings (blue, 36 hole only); standard connector for normal forks or SL, and three basic types: non-disc as shown above, a Centerlock disc version and a version for ISO disc, both shown below. Since the flange diameter is smaller than the current hub, 40 and 48 hole drilling isn't possible, so a special version with larger flanges is made for 40 spoke and 48 spoke wheels. See below.
     
SCH303201 SON 28, Polished, 32 hole $309.00
SCH303601 SON 28, Polished, 36 hole $309.00
     
SCH303291 SON 28, Silver Anodized, 32 hole $309.00
SCH303691 SON 28, Silver Anodized, 36 hole $309.00
     
SCH303211 SON 28, Black Anodized, 32 hole $309.00
SCH303611 SON 28, Black Anodized, 36 hole $309.00
     
SCH303221 SON 28, Red Anodized, 32 hole $323.00
SCH303621 SON 28, Red Anodized, 36 hole $323.00
     
SCH303641 SON 28, Blue Anodized, 36 hole $323.00
     
SCH303662 SON 28, Orange Anodized, 36 hole $323.00
     
SCH303672 SON 28, Light Green Anodized, 36 hole $323.00

 

SONdelux
     

chainring

     
New in 2008, the SONdelux (originally called the SON20R) is a smaller, lighter version of the SON for 16" and 20" rims. I stock it in polished, silver anodized, black anodized, and red (see below). The smaller size results in a considerable weight savings, dropping from the 570 grams of the Classic SON20 to 390 grams for the SONdelux. The SONdelux is also available for Centerlock disc brakes with either 32 or 36 spoke holes, and either polished, black or red anodized finish. Disc hubs are shown further down on this page.
     
SCH242001 SONdelux, Polished, 20 hole $309.00
SCH242401 SONdelux, Polished, 24 hole $309.00
SCH242801 SONdelux, Polished, 28 hole $309.00
SCH243201 SONdelux, Polished, 32 hole $309.00
SCH243601 SONdelux, Polished, 36 hole $309.00
     
SCH263291 SONdelux, Silver Anodized, 32 hole $309.00
SCH263691 SONdelux, Silver Anodized, 36 hole $309.00
     
SCH242011 SONdelux, Black Anodized, 20 hole $309.00
SCH242411 SONdelux, Black Anodized, 24 hole $309.00
SCH242811 SONdelux, Black Anodized, 28 hole $309.00
SCH243211 SONdelux, Black Anodized, 32 hole $309.00
SCH243611 SONdelux, Black Anodized, 36 hole $309.00
     
SCH263221 SONdelux, Red Anodized, 32 hole $323.00
SON 28 Tandem
     
The current SON28 has smaller flanges than older SON28 hubs, and so only has space for up to 36 spokes. So Schmidt makes the SON28 Tandem hub with larger diameter flanges, with either 40 or 48 spoke holes.

hub

SCH304092 SON 28 Tandem, 40 hole, Silver Anodized $309.00
SCH304892 SON 28 Tandem, 48 hole, Silver Anodized $309.00

chainring

SCH304812 SON 28 Tandem, 48 hole, Black Anodized $309.00
     
     
SON28 Disc with Traditional 9mm Axles
     
     
SON28 ISO Disc
     
     

chainring

   
Shown here, the ISO disc version in silver anodized finish. The six bolt interface for attaching the disc is called ISO.
   
SCH313201 SON 28, ISO Disc, Polished, 32 hole $336.00
SCH313601 SON 28, ISO Disc, Polished, 36 hole $336.00
   
SCH312891 SON 28, ISO Disc, Silver Anodized, 28 hole $336.00
SCH313291 SON 28, ISO Disc, Silver Anodized, 32 hole $336.00
SCH313691 SON 28, ISO Disc, Silver Anodized, 36 hole $336.00
   
SCH312811 SON 28, ISO Disc, Black Anodized, 28 hole $336.00
SCH313211 SON 28, ISO Disc, Black Anodized, 32 hole $336.00
SCH313611 SON 28, ISO Disc, Black Anodized, 36 hole $336.00
   
SCH312821 SON 28, ISO Disc, Red Anodized, 28 hole $350.00
SCH313221 SON 28, ISO Disc, Red Anodized, 32 hole $350.00
SCH313621 SON 28, ISO Disc, Red Anodized, 36 hole $350.00
   
SCH313641 SON 28, ISO Disc, Blue Anodized, 36 hole $350.00
   
SCH313662 SON 28, ISO Disc, Orange Anodized, 36 hole $350.00
   
SCH313672 SON 28, ISO Disc, Light Green Anodized, 36 hole $350.00
     
     
SON28 Centerlock Disc
     
     

chainring

   
Shown here, the Centerlock disc version in blue anodized finish.
   
SCH323201 SON 28, Centerlock Disc, Polished, 32 hole $336.00
SCH323601 SON 28, Centerlock Disc, Polished, 36 hole $336.00
   
SCH323291 SON 28, Centerlock Disc, Silver Anodized, 32 hole $336.00
SCH323691 SON 28, Centerlock Disc, Silver Anodized, 36 hole $336.00
   
SCH322812 SON 28, Centerlock Disc, Black Anodized, 28 hole $336.00
SCH323211 SON 28, Centerlock Disc, Black Anodized, 32 hole $336.00
SCH323611 SON 28, Centerlock Disc, Black Anodized, 36 hole $336.00
   
SCH323222 SON 28, Centerlock Disc, Red Anodized, 32 hole $350.00
SCH323622 SON 28, Centerlock Disc, Red Anodized, 36 hole $350.00
   
SCH323641 SON 28, Centerlock Disc, Blue Anodized, 36 hole $350.00
   
   
SONdelux Centerlock Disc
     
     

chainring

   

The SONdelux disc accepts Centerlock discs from Shimano, making for quick and easy installation and removal. I have these polished, black anodized, and in red anodized. The red matches the Edelux red headlight as well as the Rohloff 14 speed hub in red.

Some people want to use the SONdelux with 700c rims. Since this combination results in the hub spinning slower at a given speed than it was designed for, there will be slightly less drag, and the lights will reach full intensity at a bit higher speed. This is fine if you'll only be using modern LED headlights that reach high intensity at a very low speed. But if you ever want to use a charger to keep you phone or GPS charged on tour, you'll more power at low speeds with the SON28.

   
SCH253201 SONdelux Disc (Centerlock) Polished, 32 hole $336.00
SCH253211 SONdelux Disc (Centerlock) Black, 32 hole $336.00
SCH273221 SONdelux Disc (Centerlock) Red, 32 hole $350.00
     
     
SON28 135mm
     
     

chainring

   

For winter riding, "Fat Bikes" are the way to go. With 4" or 5" wide tires you can ride through deeper snow than with a normal mountain bike tire. But you need a wider fork. So "Fat Bikes" use a 135mm front axle and very wide rims. The SON 28 135 has a 135mm axle and the ISO disc mount is offered with two different disc spacings, for different forks.

RS 10mm is for forks designed for the rear disc spacing. FS 9mm is for forks using the traditional front disc spacing. For example, rear disc spacing with 10mm axles fit a few bikes like Tumbleweed Bicycle Co. and the Surly Pugsly. Since demand for these has dropped dramatically in the past two years, the black version is discontinued. We still have some left in silver anodized finish.

   
SCH313298 SON 28 135 RS 10mm. Silver Anodized, for ISO disc, Rear Standard, 32 hole $378.00
SCH313219 SON 28 135 FS 9mm. Black Anodized, for ISO disc, Front Standard, 32 hole $378.00
     
     
Thru-Axle Hubs
     

Thru-Axle forks and hubs are much better for bikes with disc brakes than are traditional hollow axle hubs because Thru-Axle hubs ensure perfect alignment of the disc every time you install the wheel. But with a dynamo hub, there's a catch. Standard hubs with Thru-Axles don't require the skewer to be as tight as it would need to be on a traditional hollow axle hub. The skewer only needs to be tight enough so that it doesn't come loose while you ride, whereas a QR in a hollow axle hub must be tighter, lest the hub work its way out of the dropout. So cyclists with Thru-Axle hubs quickly get used to installing the skewer less tightly than they would with a hollow axle. This can cause trouble with a dynamo hub.

If the dynamo hub is not held tightly in the Thru-Axle dropouts, the hub will vibrate a bit and the axle will rotate. If it rotates enough there will be stress on the wires and the spade connectors embedded in the axle. Either the wires or the spade connectors will be damaged, and no power will come from the hub.

When you first install your SON Thru-Axle hub, carefully notice the orientation of the connectors. Perhaps align them straight down if possible, with the wire then looping around and up the fork blade. Ride for a few minutes with the lights on, or with your phone charging. Then stop and notice if the connectors are still pointed straight down. If they have rotated a bit clockwise, you'll know that your skewer was not tight enough. Make the skewer tighter and do the experiment again. Once you have the skewer tight enough so that the connectors never rotate, you're good to go.

     
SONdelux 12
     

chainring

   
The SONdelux 12 is for those groovy new road and gravel bikes with disc brakes and 12mm thru-axles. Available only for Centerlock discs. If you wish to use an ISO disc, you'll either need an inexpensive adapter, or get the SON28 12 ISO instead.
   
SCH392410 SONdelux 12mm Centerlock 24 hole Black $378.00
SCH392810 SONdelux 12mm Centerlock 28 hole Black $378.00
SCH393210 SONdelux 12mm Centerlock 32 hole Black $378.00
   
SCH393290 SONdelux 12mm Centerlock 32 hole Silver $378.00
   
   
SON28 12 Centerlock
     

The SON28 has a bit more power at low speed than the SONdelux so it's a bit better for those who use the hub's power for charging a GPS or mobile telephone on tour.

     

chainring

   
   
SCH402410 SON28 12mm Centerlock 24 hole Black Anodized $378.00
SCH402810 SON28 12mm Centerlock 28 hole Black Anodized $378.00
SCH403210 SON28 12mm Centerlock 32 hole Black Anodized $378.00
SCH403610 SON28 12mm Centerlock 36 hole Black Anodized $378.00
   
SCH403290 SON28 12mm Centerlock 32 hole Silver Anodized $378.00
   
SCH402820 SON28 12mm Centerlock 28 hole Red Anodized $392.00
SCH403220 SON28 12mm Centerlock 32 hole Red Anodized $392.00
SCH403620 SON28 12mm Centerlock 36 hole Red Anodized $392.00
   
   
SON28 12 ISO (100mm axle)
     

The SON28 has a bit more power at low speed than the SONdelux so it's a bit better for those who use the hub's power for charging a GPS or mobile telephone on tour.

     

chainring

   
   
SCH413200 SON28 12mm ISO 32 hole Polished $378.00
   
SCH412410 SON28 12mm ISO 24 hole Black Anodized $378.00
SCH412810 SON28 12mm ISO 28 hole Black Anodized $378.00
SCH413210 SON28 12mm ISO 32 hole Black Anodized $378.00
SCH413610 SON28 12mm ISO 36 hole Black Anodized $378.00
   
   
   
SON28 12 110 Boost Centerlock (110mm axle)
     

Same as above but for the wider 110mm forks.

   
SCH432410 SON28 12 110mm Centerlock 24 hole Black Anodized $405.00
SCH432810 SON28 12 110mm Centerlock 28 hole Black Anodized $405.00
SCH433210 SON28 12 110mm Centerlock 32 hole Black Anodized $405.00
   
SON28 12 110 Boost ISO (110mm axle)
     

ISO for the wider 110mm forks.

   
SCH422410 SON28 12 110mm ISO 24 hole Black $405.00
SCH422810 SON28 12 110mm ISO 28 hole Black $405.00
SCH423210 SON28 12 110mm ISO 32 hole Black $405.00
   
SON28 15 ISO (100mm axle)
     
     

chainring

   
   
SCH333202 SON 28 15, Polished, ISO disc, 32 hole $405.00
   
SCH333291 SON 28 15, Silver Anodized, ISO disc, 32 hole $405.00
SCH333691 SON 28 15, Silver Anodized, ISO disc, 36 hole $405.00
   
SCH332812 SON 28 15, Black Anodized, ISO disc, 28 hole $405.00
SCH333211 SON 28 15, Black Anodized, ISO disc, 32 hole $405.00
SCH333611 SON 28 15, Black Anodized, ISO disc, 36 hole $405.00
   
SCH333221 SON 28 15, Red Anodized, ISO disc, 32 hole $419.00
SCH333621 SON 28 15, Red Anodized, ISO disc, 36 hole $419.00
   
SCH333241 SON 28 15, Blue Anodized, ISO disc, 32 hole $419.00
   
   
SON 28 15 110 (110mm axle, AKA Boost) ISO disc interface
     

Some suspension forks are now being made with 110mm dropout spacing. This allows the disc hub to have symmetrical spoke flange spacing for increased lateral loads. Black, Silver or red only. No photo yet, but these look about the same as the 100mm version above, just a bit wider. Flange spacing, 55mm.

     

chainring

   
   
SCH383290 SON 28 15 110, Silver Anodized, ISO disc, 32 hole $405.00
   
SCH382810 SON 28 15 110, Black Anodized, ISO disc, 28 hole $405.00
SCH383210 SON 28 15 110, Black Anodized, ISO disc, 32 hole $405.00
SCH383610 SON 28 15 110, Black Anodized, ISO disc, 36 hole $405.00
   
SCH383220 SON 28 15 110, Red Anodized, ISO disc, 32 hole $419.00
SCH383620 SON 28 15 110, Red Anodized, ISO disc, 36 hole $419.00
   
SCH383240 SON 28 15 110, Blue Anodized, ISO disc, 32 hole $419.00
   
   
SON 28 15 110 (110mm axle, AKA Boost) Centerlock
     

Same as above but for Centerlock discs rather than ISO discs.

     
   
   
SCH382810 SON 28 15 110, Black Anodized, Centerlock disc, 28 hole $405.00
SCH383210 SON 28 15 110, Black Anodized, Centerlock disc, 32 hole $405.00
   
   
SON 28 15 150mm
     

The Rock Shox Bluto fork for fat bikes uses a 150mm wide thru axle, so of course Schmidt makes a suitable hub. Flange spacing is symmetrical, 83mm wide, 58mm diameter. ISO disc only.

     

chainring

   
   
SCH373210 SON28 15 150mm, thru-axle 32 hole, black $473.00
   
   
Got a Trike?
     

If you have a tadpole style tricycle, two wheels in front, one in the rear, there may be a SON to fit. Schmidt makes several versions of the SON for trikes; the SON XS-M. This hub comes with different axles for different trikes. One for the HP Velotechnik Scorpion, and one for the Anthrotech. Also for ICE and Toxy trikes. If you have a Greenspeed trike, you can ask Greenspeed to sell you a kit which allows fitting the Anthrotech version to the Greenspeed trike. For 2013, we now have a version for the Catrikes. The 32 hole Catrike version is a bit more expensive since it requires additional hardware.

A few years ago, Catrike used 28 spokes for their 16" wheels, and 32 spokes for their 20" wheels, you must order the correct drilling. We have both. But be aware that Catrike now only builds their trikes with 32 spoke wheels, so I have a few hubs for 28 spokes left over, and have discounted them quite a bit. Hence the lower price for the 28 spoke version.

The SON XS-M accepts an ISO disc only. There is no version for Centerlock discs. There is no drum brake version. So if your trike uses drum brakes, you must have it converted to use disc brakes. The SON replaces either one of the front hubs on a tadpole style trike. Put it on the right or the left, it makes no difference. Higher spoke counts are not necessary since these trikes use either 16" or 20" rims.

     

chainring

   
   
SCHXS-M36B SON XS-M for HP Velotechnik Scorpion, 36 hole, Black $446.00
   

chainring

   
SCHXS-M32B SON XS-M for Anthrotech and Greenspeed, 32 hole, Black Anodized $446.00
   
SCH222811 SON XS-M for Catrike, black anodized, 28 holes (adapter included) $280.00
SCH223211 SON XS-M for Catrike, black anodized, 32 holes (adapter included) $446.00
   
SCH223601 SON XS-M for ICE Trike or Toxy, 36 hole, Polished $446.00
     
     
Schmidt Semi-Radial Wheels for Brompton Folding Bikes
     

Wilfried Schmidt makes wheels to replace the stock front wheel on a Brompton so you can have a quality Schmidt dynamo for not a lot of money. This new SON XS hub uses radial spokes and the same rim Brompton uses. The spokes are all stainless steel and the rims are all either silver anodized or black anodized.

   
   

chainring

   
SCH43140 SON Semi-Radial with Silver anodized Brompton rim with Polished hub and stainless spokes $418.00
   
SCH43110 SON Semi-Radial with Silver anodized Brompton rim with Silver anodized hub and stainless spokes $418.00
   
SCH43151 SON Semi-Radial with Black Brompton rim with black hub and Black spokes $450.00
   
   
Polished or Anodized?
     

chainring

Most versions of the SON are made with the aluminum shell polished to a high shine. And almost all of the models are also available with the shell anodized a glossy black, silver or red. We have a few in Blue, Orange or Light Green. No Paisley as of this writing. Some people prefer the aesthetics of one over the other. I'm solidly in the polished camp, since I like the look of old classic bikes from the 1970's. Other than aesthetics, there are only three considerations when trying to decide between polished or anodized. In some models you have few choices. In some models, where there is a choice, the anodized version is more expensive. But most importantly, if you ride all year long and the roads where you ride are salted in the winter, the road salt will cause the polished surface to stain, whereas the anodized surface will remain shiny, like new.
If you have a red anodized Rohloff hub and want a SON hub and headlight to match, the colors will all be the same, since Rohloff and Schmidt use the same German company to anodize their products.
If you want the lightest dynamo hub, get the standard SONdelux with 50mm spaced flanges, below. But if you want the most stable wheel possible and don't mind the slight added weight (about 24 grams) and cost, get the SONdelux Wide Body with 68mm spaced flanges. That's what I use on my road bike. I weigh 165 lbs and use the 32 hole with a Mavic Open Pro rim. The SONdelux Wide Body is available in 28, 32 and 36 hole drilling, polished, 32 hole in black, and for rim brakes only. There is no disc version. But with disc brakes, if the rim is flexing laterally while your climbing, it doesn't matter since that doesn't affect the brakes.
     
   
The Gizmo Factor!
     
You can charge batteries from your SON hub if you can convert the AC output of the hub to DC. We have several "chargers" that do just that. Most of these chargers output at the USB specification only. If you only charge USB devices, you'll be fine with the USB-WERK, or The Plug III, or Appcon 3000. If your device charges with different voltage and amperage limits than USB, you should consider the E-WERK from Busch & Müller

Click here for the Appcon 3000 page.

Click here for the Busch & Müller USB-WERK page.

Click here for the Busch & Müller E-WERK page.

Click here for The Plug page.

     
   
Disc version on a Tandem?
     
Years ago, I didn't recommend disc brake versions of the SON for use on a tandem. We thought that high heat from the disc could make the hub shell too hot, damaging the magnets inside. But extensive testing has shown that the disc rotor itself fails before enough heat reaches the hub shell to damage the magnets. So we now are happy to recommend the disc version for tandem and heavily loaded touring applications. Of course, you should be careful not to overheat the discs, as a warped disc will ruin your ride. For long distance loaded touring, (tandem or single) you may want to carry one or two spare discs if you'll be riding in very hilly terrain. And, be aware that disc versions of the SON hub should only be used with forks fitted with dropouts that prevent the wheel from being removed (lawyer lips) even if the skewer is loose. Otherwise, torque from the brake can cause the hub to work its way out of the dropouts.
     
   
Crosses to Bear?
     

Older, pre 2012 Schmidt hubs should not be used in a wheel with radial spoke lacing. Newer non-disc hubs can be radial spoked. If you are crossing the spokes, don't have too many crosses. If the spoke contacts the hub flange at a tangent, the wheel becomes less laterally stable. This is true of any bicycle wheel with tensioned spokes.

24 and 28 hole versions should be laced cross 2. 32 can be laced cross 2 or 3. 36 should be laced cross 3. 40 hole can be laced either cross 3 or 4. 48 should be laced cross 4.

     
   
Wheelbuilding Data
     

Please see the SON website which has a nice spoke length calculator for all SON hubs.

Click here for the SON Spoke Length Calculator.

     
   
SON28 Klassic Hub Alignment
     

Some older, pre 2012 SON dynamo hubs must be used with the connectors only on the right side of the bike. The original version (before 2001) of the SON28 has polished aluminum flanges with a black painted steel center shell. That version can be used with the connectors on either side of the bike. The later SON28, now called the SON28 Classic, SON20, and any disk version for a normal bicycle fork must have the connectors on the right side. SONXS, SONXS 100, SON20R and SONdelux can be used either way. SON20R Disc and SONdelux Disc must have their connectors on the right side.

     
   
Don't these dynamo lights Blow Up?
     

If you do a search on the internet for bicycle dynamo lighting systems, you will undoubtedly come across warnings about bulbs burning out if you ride your bike too fast. This is true of systems designed back in the 1920s, and used on bikes such as Raleigh three speeds up through the early 1980s. These were very crude systems by today's standards, with no voltage limiting. While you can still buy cheaply made dynamo lights that will blow bulbs on a downhill run, none of the systems I sell are so poorly made that you have to concern yourself with this. Without exception, every headlight I sell for use with either a hub dynamo or sidewall dynamo incorporates circuitry to prevent the overvoltage of the bulb. You have absolutely nothing to worry about.

     
   
Schezbzflaxz! My hub feels notchy!
     

When you hold the wheel or hub in your hand and turn the axle, you'll feel a lot of resistance. There are 26 poles and 26 magnets in the SON28 hub (fewer in the SONdelux). That creates 26 points around the hub shell that the axle wants to settle in, and a corresponding 26 points where the axle doesn't want to be. In the transitions between those points, the axle wants to turn in one direction or the other, to find the point where it wants to settle. As you ride, the hub turns relative to the axle, and 26 times in each rotation of the wheel, the hub wants to turn one way, and then the other, theoretically speeding you up and slowing you down, 26 times per rotation. At speed, the effects of these two forces almost completely cancel each other out, leaving you with extremely low drag overall. It's only when you don't have a lot of mass (your weight) and inertia (your speed) that the effect is to actually retard the rotation of the hub axle. So there's no reason to be concerned about the way the axle feels when turned by hand.

     
   
The bearings cannot be adjusted.
     

Frequently, people decide that I'm stupid, (Who can blame them?) and that in fact the notchiness they feel while turning the axle by hand is due to the bearings being adjusted too tightly. This is not the case. There is no adjustment for the bearings! They are sealed cartridge bearings, and require no adjustment. Nor is adjustment even possible.

On the end of the axle opposite the electrical connectors of older SON hubs, the black aluminum end cap has two flats on it. Those were for use while assembling the hub in Germany, not for user adjustments. But sometimes a mechanic will hold the hub in a vise by those flats, and grab the other end of the hub axle with some pliers or vise grips, there being no flats on the connector end of the axle. This genius doesn't stop to think why there are no adjustment flats on the electrical end. The brilliant mechanical wizard then turns the electrical end of the axle, in a vain attempt to loosen the bearings. Well, all this does is break the electrical connections inside the hub, making it useless for powering a light, though it will still work just fine as a front bicycle hub. It also voids the five year warrantee. You will have to send the hub to me for a repair, (assuming you want the lights to work again) which will set you back $ 75.00 plus return shipping.

The point of this little morality tale is quite simple. Leave the hub alone! If you bring your bike into your local shop for a tune-up, tell the mechanic to leave the hub alone! If the mechanic thinks he knows better than anyone else about how the axle on a SON hub should feel when turned, find yourself another bike mechanic. Only if you hear a scraping sound (an extremely rare condition which means there's corrosion on the dynamo core) while turning the axle does the hub require service. And neither you nor your local shop will be able to perform that service.

     
   
Reliability
     

The SON has proven itself to be very reliable. Only two types of problem has shown up in use. First is the mechanic damaging the hub by trying to adjust the non-adjustable bearings. The other has to do with water getting into the hub.

As with any bicycle hub, if the wheel is kept indoors and you take the bike out to ride when it's cold and raining, the temperature of the air inside the hub will drop and the air pressure will drop. That creates low air pressure inside the hub that can suck water inside through the bearings. Even though the bearings are sealed this can happen. It happens on other sealed bearing hubs as well. But in the older SON, once water gets past the bearings, it can cause corrosion on the dynamo poles. As the poles corrode, the surface rust will contact the magnets (the gap between the poles and magnets is extremely small) and the hub will bind. To prevent this from happening, put the bike outside in the cold for 10 minutes or so and let the hub cool down while it's dry. Then head out into the rain. When the air inside the hub is at ambient temperature and stays there, the pressure inside the hub is constant, and no water is sucked inside.

Current production hubs (since early 2003) have an ingenious system to prevent water from getting far enough into the hub to cause corrosion. So this is an issue for older hubs, but not for any hubs you would be buying now, or might have bought since early 2003. For this system to work, there is a tiny hole in the middle of the axle. You can see it if you remove the skewer and look down the axle. And for the system to work, this little hole must be open, not clogged up with grease. So if you grease your skewers, just put a very thin layer of grease on them. Don't slather grease in a thick layer all over the skewer as it might clog up the little hole and then it's possible for water to get sucked in through the bearings, causing corrosion. So if you grease the skewer, wipe most of the grease off before putting it into the axle.

All hubs sold since Jan 1, 2004 have a five year warrantee. But if you clog the axle hole with grease, you void the warrantee!

If you need to send me your hub for service, do not cut out the spokes without checking with us first. Depending on the version SON you have, I may need the wheel intact in order to open the hub shell and work on the innards. Here are the versions.

(1) First type has polished aluminum flanges and a black steel center shell. To open this hub, the spokes must be cut.

(2) Second type has a one piece aluminum shell, either polished or black anodized. To open this type, the hub must be built into a wheel. Then a tool is attached to the electrical side and the inner core is removed by unthreading to the side with lots of torque. This cannot be done without the special tool which is not available for sale.

(3) Most of the newer additions to the SON line of dynamo hubs require cutting the spokes to open the hub for service. This includes the SONXS versions for folding bikes having narrow forks; Dahon, Moulton, Brompton, Tikit, SONXS 100 for normal forks but using thesame narrow hub shell, SON XS-M for trikes, and the SON20R/SONdelux. Once you are certain that any of these last types need to be opened up, you might as well cut out the spokes before shipping the hub to us since a smaller lighter box often costs less to ship.

     
   
Do you like to tinker?
     

I'm a bicycle mechanic, who happens to import some very nice bicycle lights from Germany. I frequently get phone calls or email from people who want to try a different way of connecting their lights, often through the use of their own switch box, and they want my advice. Others want to use the output of the Schmidt hub for recharging Uranium PU36 Explosive Space Modulators. Now, I like Uranium PU36 Explosive Space Modulators as much as the next guy, but unless it can be charged via a USB computer port, I have no advice to give regarding powering one from the Schmidt. I only support using the Schmidt hub with the lights I sell, with the wiring pattern I recommend or with the USB chargers I sell. If you would like to try something different, be my guest. I wish you all the best, and I'm happy to sell you a hub, but you're on your own.

     
   
Wiring Instructions?
     

For wiring instructions, please go to the Wiring Instructions page.

For more technical information about the Schmidt hub, please read the text of Wilfried Schmidt Maschinenbau's brochure for the Schmidt's Original Nabendynamo or "SON". I've taken the liberty of editing their English translation from German to better suit the American reader.

     
   

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This page updated: Monday, May 20, 2019

Peter White Cycles LLC
24 Hall Rd.
Hillsborough, NH 03244
USA
603 478 0900 Phone