What are dynamos and why do you need one?
Dynamos are ingenious cycling components, generally taking the form of a wheel hub, that allow you to harness some of the mechanical energy that you are generating when you ride your bicycle. This energy rather than being used to exert force upon the wheels to help them turn is instead captured by the dynamo and converted into electrical energy which can then be used by the rider for another use. Therefore for the modern cycle tourer or commuter, often travelling with many electronic gadgets, they can be an invaluable source of electricity, allowing you to generate your own green-energy and also be electrically self-sufficient.
How to go about getting your first dynamo:
There is no way around it, getting a dynamo and the associated converters is a big investment for most people. However for my cycle from Alaska to Mexico I knew it would be a worthwhile investment. This is because I knew I would be camping the whole time with limited access to power and that being able to charge my phone, GPS, camera, bike lights and other electronics whilst cycling would be invaluable as it would allow me to continue on cycling and also do the things I like to do whilst on tour, like photography.
I was therefore faced with the option of either getting a solar charger or a dynamo charger. I have heard mixed reviews about solar chargers, and the overwhelming consensus was that a couple are okay on sunny days but I wouldn’t be able to charge up as many gadgets reliably compared to if I invested in a dynamo hub.
I therefore decided to start researching and exploring the –surprisingly- large market of dynamo hubs. There are a large amount on offer and the prices range from cheaper Shimano hubs at around £50 to the highly expensive Schmidt SON dynamos at over £200. Roughly you get what you pay for, the more expensive the more efficient, the more reliable, and the lighter the hub is going to be (dynamo hubs understandably carry a significant weight penalty over normal hubs however the addition of a few grams is less important if it is used on a commuter or touring bike). I found this article by the CTC comparing a few models very useful and well worth a read if you are considering purchasing a dynamo.
As you can see in that article the Shutter Precision sticks out as not only being the most affordable dynamo but also not far off the most expensive dynamo manufacturer on the market, both in weight and in efficiency. The only question mark seemed to be over reliability, and due to the large difference in price between the two I decided that was a risk worth taking. As my touring bike (Genesis Tour de Fer) has disk brakes I opted for the SP-PD8, the 6-bolt disk hub version of their most popular dynamo hub.
SP 8-Series Review
The 8-series of dynamo hubs are undoubtedly the best value for money hubs on the market, this I know after Tom and I have ridden over 12,000 kilometres on them this summer. To be honest most people are put of the idea of dynamo hubs because they think the drag will slow them down even more. However with a hub that operates at around 70% efficiency to give a 6volt 3watt output, there is just no discernable difference to riding with or without the dynamo hub –even more so on a loaded touring bike.
The 8 series come in a variety of formats so that they can cater for pretty much every style of bicycle, depending on the style of your brake and also the number of spokes in your wheel. These factors will affect the weight of the hub however the SP dynamos manage to come in significantly lighter than their competitors at the similar price and are a similar weight to the Schmidt SON hubs, which are significantly more expensive. So my verdict on the whole package of price against efficiency and weight was that the SP-PD8 I got was very good value-for-money.
When my dynamo arrived it looked amazing, I ordered a red coloured dynamo so that it would match the frame of my bike. After a quick wheel rebuild, courtesy of my local bike shop, the wheel was ready to roll. I hooked the dynamo up to a USB converter to convert the AC output from the dynamo into a DC current that I could use to charge my electronic gadgets (I will write an upcoming post on these). This DC current I fed into a large Anker rechargeable battery which has two USB outputs for charging and from full can charge an iPhone six times. It may sound like a complicated set up, however those three items hooked together made me electrically self sufficient and meant that I could not only charge gadgets whilst riding but also using the Anker I could charge items in my tent in the evening.
Before leaving for Alaska I completed a couple of training rides with this set up and was really happy with the results, I felt no additional drag from having a dynamo versus a normal hub but was also satisfied that I could now cycle wherever I wanted to in the world and I would always have power to charge up my camera, GoPro, and iPhone (which I eventually used for GPS). It was the perfect set-up.
I also cycled with my good friend Tom, who along with me had exactly the same set up for charging –same bicycle as well. So with two of us electrically self-sufficient this was perfect as it meant that one of us wasn’t reliant on the other for charging. It also meant that halfway through our journey when we decided to purchase a set of USB speakers we could power these directly from the USB converter connected to the hub, our music was powered by our pedalling. This made us very popular through Oregon and California as we were the guys who had the tunes playing from our bicycles and we could have a good singsong whilst riding, which really does help the miles fly by.
After over 6000 kilometres both mine and Tom’s hubs are still rotating perfectly and giving us electricity. We have encountered no problems with them at all. This we were particularly surprised about as through the Yukon we were cycling on rough gravel roads, through thunder and rain, the hubs really did take a battering from the road and the elements. We had no broken spokes or bent despite very heavy bikes weighing in at over 50 kilograms. This we were really worried about as beginning our journey in Anchorage as due to the slightly wider hubs our spokes were running very close to our disk brakes however they never touched or broke no matter where we rode.
To say I am impressed with these hubs would be a big understatement. I was very worried that they would make it when we got to Anchorage and when we saw the quality of the roads we would be cycling on. However they have lasted through it all and they look like they could do it all again –another ten times. Tom and I now have a combined over 12,000 kilometres riding on these hubs, and quite a lot of that was on some very rough roads. So with the reliability box checked I am really struggling to find a fault with this hub.
It is testament to Shutter Precision that they are able to make such a reliable, efficient, and lightweight hub for such an affordable price. With hubs like this on the market I really think more people should be using them, it just makes so much sense and does work out cheaper in the long run. If you are going on a long cycle tour then having one probably isn’t a necessity but it will probably make your life a lot easier, and if your cycle touring for fun and enjoyment then why not make your life a bit easier? It also seems that Shutter Precision are intent on getting their hubs more efficient and lighter too with their 8X and 9-series hubs. With all this innovation I am glad to see that they are still striving to make their already great hub even better.
Pros: Reliable, Efficient, Value-for-money
Cons: Still carries a slight weight penalty over more expensive models, if only a couple of grams.