I’d be the first to admit, I am a Power Hog. Though I am on the road on my bike for years now, being a technophile, I do numerous things on the road electronically. Taking pictures (multiple cameras), videos (Garmin Virb), listening to Music (knock off mp3 player), Reading books (kindle), Writing my blog (iPad Mini), Routing and mapping (Garmin Oregon 600) and the mother of all, a Notebook computer (Apple macbook pro) for putting everything together, occasional work on the road, entertainment, storage, photo processing etc… It’s an absolute luxury and a potential theft magnet I know. I am careful about where and how I display my stuff and generally keeping a low profile and not flaunt the stuff.

However, carrying a lot of electronics meant that I had to find ways to keep them powered up. I had thought of various options and years back when I had an opportunity, I bought a Shimano dynamo front hub (Wish I had a SON) which had been ticking along without complaints for nearly 25,000 Km on the road and hopefully will keep ticking along. Since I had my dynamo, it was obvious that I should set up dynamo lights too. And that’s one of the best things I’ve done.

This review is about the little USB adapter and I should stick to it.

In the recent years there had been a proliferation of USB adapters that can provide reasonable charging options fed by the bicycle dynamo. There are numerous options out there (all at about the same price range). I had done a bunch of research and even bought a Pedal Power+ and was disappointed with it. So when I got on my second tour, one in the Americas, I was on the lookout for reliable USB charging options.

I came across the Sinewave Cycles (Love that name) reactor and their claim that the contact terminals were corrosion proof. The reactor had a great design, a la, Tout Terrain the Plug. It would fit on the head tube and I really wanted to try it. The product was still new to the market and I wrote to Sinewave cycles asking if they would sponsor me one of their products so I could try it on the road and provide feedback. They were really friendly to deal with and though they had some production back logs on their Reactor, they gladly gave me a Sinewave cycles Revolution for me to try. I had it shipped forward to a friend’s place in Santa Barbara and picked it up when I got there.

On the physical aspects and weight etc, the website has a lot of details. Suffice it to say that they installation was simple. I just had to zip tie the USB unit to my stem and the external leads to an adaptor that would plug into my dynamo.

Ok, first up, my Shimano front dynamo (and pretty much every hub dynamo for that matter) supplies 3W or power when the bike’s up to speed and that means I can use only one of my USB out or the lights on my bike at a time (Correction: I got feedback from Sinewave that both lights and charging can be done at the same time with the Revolution – however, due to limited output of the dynamo, the lights will be dimmer and charging slower). I had setup a dynamo powered front and rear light system and to avoid conflict, set up a separate connection for the Sinewave Revolution. The idea was that during the day’s ride, I really don’t need the lights and I can plug in the USB and charge my batteries.

On the power output, once I am above 12 Km/h, there seems to be a steady output (this is just an observation and not a technical measurement) and it seems like when getting up to a cruising speed of 15 Km/h, the output is definitely steady and reliable. On a touring bike, with the continuously changing road conditions, traffic, climbs and descent, its pretty uncommon to keep the bike above 15 Km/h consistently. While charging my GPS, iPad Mini or my MP3 Player directly, the ups and downs (especially downs) in speed means that the charging starts and stops almost all of the time. Sometimes, its pretty annoying (for instance, the Garmin GPS would shutdown if I the external charging stopped). Of course, it’s not the fault of the Sinewave revolution, just a quirk of Dynamo output one has to be aware of.

As a consequence, it’s pretty much essential to add a buffer between the USB out and the device being charged. I use a couple of battery packs that I keep constantly charged while on the road and would use the battery pack to charge my devices in the evenings. On a full day’s ride (about 80 km or so) I usually ride for 6 hours or so and on average, for about 4-5 hrs, I’d be riding about 15 Km/h. That seems to be enough time to charge my 5000 mAh battery pack fully.

That is pretty much enough to top-up my GPS which is on all day long and have enough battery left over to top up by camera battery. Once every few days, I charge my iPad mini and given it has reasonably decent battery life, I could stretch it without charging for nearly a week.

I thought there might be a problem of over voltage or so at higher speeds, I have bombed thro downhills at constant 40-50 Km/h and sometimes reaching 65 Km/h. I don’t know if there is a voltage regulator in the Sinewave revolution or on my battery pack, but it seems like I’ve never had a problem of burning out my devices or cables to contacts.

There is an issue for charging my Computer, bummer, but that’s a power drain I have to manage – dynamo power ain’t going to help matters there.

I have had the Sinewave Revolution on my bike for more than a year now. I should say the contacts have been corrosion free and the power output is consistent as it was on day one! The little device has been exposed to extreme weather all along, From Mexico to Ecuador where I am writing the review. There has been tons of dust, heat, rain, thunderstorms and whatnot and the little device seems to be chugging along fine. I suppose not that much can be said of the cables that came along with my electronics, some of them started to corrode and I had to replace them a couple of times already.

I mounted the Sinewave revolution on the stem at first and later decided to move it to the steerer tube with the USB socket facing down. Just felt like a sensible thing to do to keep the water out. The USB socket is a snug fit and at first I had trouble getting any output. I realised it was because the fit was super tight and I had to forcibly squeeze my usb cable in. This really tight fit is essential, I suppose. Due to the vibrations that the bike takes, all the connections (sometimes even screws on my bike) come loose. Once the USB cables loosens from the socket, the contacts become unreliable. But the Sinewave revolution, with it’s tight fit seems to be working along well.

Just in case though, it would be nice if there was a way to plug the cable in and have some sort of retaining mechanism, a lock of sorts, to keep the contacts engaged. It’s not a problem yet, but all my devices that I used to charge while on the bike have loose contacts and I suppose in a few years of use, the Revolution will pry loose too.

Overall, I would say the Sinewave revolution works as advertised. It has been reliable and extremely weather resistant in nearly 15 months of rugged use while touring the Americas. I suppose the only issue is to have a realistic expectation of an Dynamo based charging situation. The power output trickles and while touring on a loaded bike, it’s tough to maintain speeds about 15 Km/h all the time. So the charging will be intermittent. A battery pack is essential in my opinion and they are pretty cheap these days.

When I got the product from Sinewave Revolution, I offered them an honest review based on real world use. I am genuinely happy with the product and would gladly pay for it. It’s an expensive addition to the bike, especially the fact that if you did not already have a Hub Dynamo, you’d have to rebuild the wheels with the dynamo. If you already have a hub dynamo though, the addition is pretty useful. If you are away from power sources for long stretches of time, and it’s important for you to keep some charged batteries, then I’d highly recommend the Sinewave revolution.


  • Super weather resistant. Would be nice if the supplied a rubber or Silicone cover for the USB socket.
  • Easy to Setup
  • Works as per specs
  • Limited Power output (due to dynamo Limitation)
  • Need to switch between lights and USB (Correction: Revolution would be able to run both lights and an USB output at the same time, however with dimmer lights and slower charging)
  • Consistent output at and above 15 Km/h (depends on wheel size of course)
  • Highly prefer to use a buffer battery.
  • Able to charge 5000 mAh battery in a full day’s ride.

Track Notes