Schmidt's SON 28 15 Generator Hub Review

Schmidt's SON 28 15 Generator Hub Review

This is a detailed account of the performance I experienced from using the Schmidt's SON 28 15 generator hub, which includes things like how well it charged devices, and what kind of devices I used. Buckle up, it's a doozy.  (The SON 28 15 is designed for a thru-axle.)

Read More

Generator Hub for Bikepacking

I'll try to make this a friendly read for both the nerdist and the skimmer.  Nerds, read the fine print.  Skimmers, read the bold print. 


When I first started researching what I would do for power a couple months ago, the pieces of the puzzle weren't really lining up in a way that made sense.  Far as I could tell, there were about four options for power on the trail:

  1. Slave to the Outlet - can you picture yourself asking for the outlet at a hometown diner while cowboys sit down to eat ? I can't. 
  2. Batteries - disposable, easy to buy at gas stations, lots of them, plus a USB battery pack for your phone
  3. Solar Panels
  4. Generator Hub

They rank in that order of up-front cost.  Option 1 and 2 didn't really appeal to me.  I'm an environmentalist at heart, so I was actually interested in seeing if there were creative ways to power up.  Narrowed down to solar panels and a generator hub, here's why I chose generator hub

  1.  Solar Panels - These are probably not a bad option if you have a rack that allows for a flat-ish surface upon which you can strap the panels while you ride.  However, for my bikepacking setup, I am using soft bags and this real estate just isn't there.  Considering that I'd be biking for most of the day, this leaves very few sunny hours that I could spread out the array.  Solar panels need sun.  It gets cloudy; nuff said? 
  2. Generator Hub - I'm going to be biking 6 - 7 hours a day.  Wouldn't it be great to constructively use some of that wattage?  At first, it seemed like a dynamo hub would be too delicate for off-road application, but Schmidt's and Shutter Precision (SP) make robust thru-axle dynamos. Rain or shine, as long as I'm going faster than about 5 mph, I can charge stuff. 


As far as I can tell, there are TWO companies that make dynamos for thru-axle bikes.  (Most new mountain bikes have a thru-axle. Not sure what this means? Click here.) I could've switched to skewer, but with all the miles I was going to put on the bike, it seemed like I should stick with the more robust option. 

SCHMIDT'S  - German engineering, historically the company for high-end dynamos, first prototype in 1992 - They offer legacy in tried-and-tested products, which is backed by a 5-year warranty. Evidently their "pressure compensation system" is supposed to prevent water from intruding due to difference in temperature, and is now incorporated into all the SON dynamos. The SON 28 15 goes for about $380.00 USD after taxes and shipping.

SHUTTER PRECISION - Taiwanese company, formerly a digital camera shutter company, newer to the dynamo scene (2008) - However they have designed their dynamo, they tout an innovative approach that achieves remarkable efficiency at higher speeds.  And a for a price that won't make you gulp, hard. One can get an SP 8x for about $215.00, which comes with a 2-year warranty. 

A note about customer service: Both were excellent - Although it took a little longer for SP to get back to me (presumably because of the time difference), both companies emailed thoughtful responses when I asked them technical questions, even adding details that I didn't know to think of (e.g., wheel building specs).  Additionally, each of the companies were transparent about their product, even when being compared to their competitor.  Verbtaim, SP said, "SON is good at very low speed…." I really appreciated the honesty. 

Efficiency - SP claims a 78% efficiency at 15km/h (9.3 mph), which is record-breaking; however, they claim lower efficiencies at lower speeds. Schmidt's claims an efficiency of 65% at 15km/h, but have a higher efficiency at lower speeds. Personally, I would like to see third party tests of each hub to validate the data.  The most reliable information I found was from their websites, and this one German article that Google translate does a knock-out job of translating.  I say this because when I tried to compare the wattage to speed graphs from each company, it's not clear how they conducted each of their tests, so it was too hard for me to say that I was comparing apples to apples.

SP's efficiency graph - from website

SP's efficiency graph - from website

Schmid'ts efficiency graph - from website

Schmid'ts efficiency graph - from website


Durability - SP claims to have built what they consider the strongest hub on the market, but Schmidt's has the time and 5-year warranty to back up how they feel about their durability.  Other tour divide riders have used SP, but I couldn't find any review straight from the source.  My guess is that SP just needs more time to build confidence in their product. 

Price - This is where we see the big separation in the two companies. Schmidt's is almost double the price of SP.  I can appreciate that SP is making a really rad technology available to more people, but I don't believe in something for nothing, and in all of my research, I couldn't really pin down why theirs was so much cheaper.  


I ended up choosing the Schmidt's SON, but would consider SP again in the future: 

In the end, I purchased the SON because I felt the 5-year warranty said a lot for the product's durability and Schmidt's commitment to customer support.  I also felt that I would often be traveling at lower speeds on a mountainous, off-route trail, and appreciated the very high efficiencies in the range of 3-9 mph.  Lastly, I was probably scared off by the price of SP and the very high efficiencies claimed at higher speeds.  I'm a person that believes there's NO SUCH THING AS A FREE LUNCH.  I'm sure that SP has some very good manufacturing practices and high quality data to back up their claims, but I couldn't find it. However, I do believe that SP is working toward great things, and that in due time, they will be become a more established brand.  For both camps, it seems like some third-party testing is in order, and then I could really write a non-biased review.  


This hub: Schmidt's SON 28 15

with this Rectifier (aka USB converter) 
Sinewave Cycles Revolution:

I can charge a phone directly or an external battery pack.  I chose the Anker 2nd Gen 9600mAh.

My friend at Bikesport helped me figure out how to get the components quickly, and did a #supepro job building the wheel.  Many thanks!


I'll post again about performance and whatnot.  For now, I'll leave you with some pics of a hot hub.