Another unusual component for this blog: a rim dynamo. Unusual, because as you know, I am not a big user of energy producer components, as for my needs I use just a couple of battery lights and it’s better they are very small.
I need a lighting system only to be visible and not to see the road, and between the two there is a big difference. But because a component does not fit into what I would use on one of my bikes, does not mean that I should not test its effectiveness. On the contrary, just when I deal with some components and accessories I can easily do without, it means I must test them, because beyond effectiveness, it’s a healthy way to question my beliefs. And he who is always convinced, never touched by doubts and animated by curiosity, does not go on.
I came across this tiny rim dynamo, very cute and well manufactured, and reading the rich technical documentation in the website, I wondered such a small object could be capable of such performances. The light bulb immediately turned on (poor metaphor, eh?), and so immediately I requested a sample to test.
A sample that the manufacturer Velogical sent by return of post, attaching a front headlight and the necessary for the installation. I added the back light, to make the test complete. And still for the sake of completeness, this time, unlike the usual, I recourse to some pictures not taken by me, but to those albums posted online by Velogical. There are several systems of bike fitting, but asking for all of them did not make sense; and then I must say that the pictures taken by Ogando are really of great quality, I could not do the same… 😀
Let’s start by getting acquainted with our small and light dynamo.
No flask or bottle shape we have been used for years: some simple, clean, geometric lines, embellished with the precise manufacturing of the base made from the solid part.
A base that has both a couple of electric wires and two threaded holes, one of which is closed by a small Allen. The plastic cap protects the inner axis, in turn secured by a tiny seeger ring; too small for my equipment and I refrained from removing it ….
However, for the most curious of you, here is the interior, with an image taken from this comparative, in German language though.
The holes just seen correspond to those placed on the outer circumference: inside them it will run the anchorage pin to the bracket dynamo, and it will be held in place thanks to the little Allen we saw before.
The threaded holes are rightly two, and you use only one of them to secure the axis, because they have two dynamo versions, to be mounted to the left or to the right. This makes necessary to reverse the fitting and it would not have made sense to create a different “foot” depending on the fitting direction.
The overall size is really minimal, as you can see in comparison with a Euro coin.
But I like to give detailed information, so I report that the net diameter, without the rubber ring, is 27mm and its length is 37mm.
All in just 52 grams in weight, without o-ring.
When I asked for the dynamo to test, I indicated my London Road’s cart, so Velogical sent me the plate with the small clamping arch in the appropriate size. A rubber sheathing prevents damage to the paint.
The small plate has several holes to fit different sizes archs, so that it is compatible with virtually all tube diameters, whether it is steel or titanium, thinner, or aluminum, and therefore thicker. Integrated and protected by a thin layer of grease, there is the pin to secure the dynamo. Pin that will have to pass between the holes seen above, integrated to the base, and then secured with the little Allen. A soft sponge prevents scratches in contact with the frame. The spring you see in the back is the one that controls the approaching and the parting of the dynamo from the rim. Its position is regulated by some custom-size angle cuts.
The overall lenght, including the spring protrusion, is about 6,5cm.
And this is in detail the little fitting arch I used, on a 20mm diameter tube.
Adding the dynamo and the fitting, depending on the version we chose, we have a total weight of between 70 and 90 grams. We are far from any rim dynamo and very very far from the hub dynamos.
As you can see, the choice of sizes is wide, capable of covering a range from 12 to 46 mm, including not only the rear chassis, but the forks also, even those in aluminum or carbon, that have very large sheaths.
In addition to the anchorage system, the equipment includes a thermistor, i.e. a resistor with the function of protecting the circuit from excessive tension. In the picture below, we see it together with some spare rubber rings, a pair of thermo-tigthening sheathings (which are part of a more substantial equipment) and two very useful tools. The first one is a 3 Allen, to be used on that Allen securing the pin, as we saw before. The second one is a 5,5 bush, which is not always easy to find and almost never included in the normal house tools, allowing you to work on the nuts closing the fixing arch. The electrical connection cable is also included, but is nor present in the picture.
As you can see in detail, the rings are provided in two gauges: the larger one lowers the starting speed of the dynamo. The manufacturer’s guaranteed life, that anyway varies depending on the use, is between 5000 and 7000 km. Replacing it takes only few seconds and no tools.
The thermistor uses a 20w absorption bulb. It protects against over-voltage and its installation is compatible with other protection systems, such as the one manufactured by Shimano.
Using the thermistor seemed to me an excess of the manufacturer’s caution; then, after having mounted and connected the dynamo, and after a couple of push thrusts, the light power already expressed at such a low speed made me realize that the efficiency is high and some protection is needed. Connecting it is simple: a thermistor cable must be connected to a dynamo’s cable, and the other one connects to a single cable coming from the light. Placing it on the bike may require little creativity, as we will see later.
For now, I will continue with fixing the dynamo to the bike. In my case, the upper sheath lodged it, on the left side.
You should forgive my installation not so clean; but you should consider that I test the components and then I return them. It means that when I install something, I have to make sure that everything works perfectly but I have also take into account the speed of intervention for any problem or need for further test; and I have to use an installation that is the least “invasive” possible for the component, so that I can return it to the best of its conditions. This also explains why I preferred to use the bottom holes of the plate and not the upper ones where, in my opinion, it would have been better to insert the arch: for a little bit, but I could not easily pass the key I carry with me on the road and, because it’s a test, I must be prepared for any eventuality in order not to thwart a test.
Just to remedy, here are some clean and well-made fittings, still taken from the Flickr albums by Ogando, Velogical’s owner.
The fitting to the frame is not the only one available: it is also possible to use the cantilever/V-brake junction, thanks to properly-shaped plates.
They are included in the mounting hardware and obviously integrate the spring.
Here are some installation examples.
For those who are creating a custom frame, the possibility of welding a support to the frame it’s an interesting option; some examples are still visible in Ogando’s Flickr albums.
The thermistor has two small connections to be secured to the brake sheathing.
Or to some types of light brackets.
In the case of the Planet X London Road I used for this test, I had the problem of the brake sheathing with a low passage, under the cart, just to be clear. Too far from the dynamo to let me install the thermistor. I could stretch the cable, but I would have been with the security device in a exposed position. And between the risk of damaging the component and an unusual fitting, I chose this last option. By creating a rubber bearing, integrated with a little piece of brake sheath, to serve as an anchor.
A coat of paint in the color of the frame and the bearing is not even noticeable. The tangle of cables yes, but it was important to have them in sight all the time, to be able to work fast. For those who want a clean fitting, the ideal way is to pass them inside a sheath; spiral ones are quick to mount.
Talking about cables, my advice to preserve the efficiency of the current transmission is to weld them to each other. It’s simple, just a little tin and a small electric welder. We connect the ends of the cables and then “melt” a drop of tin on them, carefully spreading it with the welder.
In order to carry out the test, Velogical provided me with a Trelock light, version with a sensor for automatic ignition and switch-off, and integrated retro-reflector, according to German homologation regulations.
The automatic ignition system makes sense with the hub dynamos, many of which are not detachable and it may as well let the light to illuminate the road when it is needed. In our case, on the contrary, we can decide of engaging the dynamo or not. But the friction is so low, practically non-existent, that I often let it functioning even in daylight.
To make the full test, I applied my own rear LED light, a small BM with holes separated in 50mm. and I applied it on the luggage rack. But during this test the luggage rack has been removed, so here too I used my imagination, creating a special small clamp. A light coat of paint in the same color of the frame and disguises itself well, besides the tangle of cables….
The list of compatible lights is wide, we can say that every headlight for hub dynamos can be installed with this Velogical dynamo. In any case, in the official webpage there is a list of equipments already tested and therefore definitely installable.
Before going through my road reviews, I close this long presentation, justified by the uniqueness of this dynamo, informing you that it is available in three versions, differentiated for performances and characterized by different colors.
We have Sport, Trekking and Special.
The Sport version is recognizable by the red cap; for universal use, minimum rolling resistance and minimum engagement speed set at 10kms per hour, which lower to around 7-8km per hour using the o-ring more often.
The Trekking version has a silver cap and engages at 8kms per hour, with a thin o-ring. Probably the most suitable for city use, although I can tell you that the Sport version, the one I used, proved to be perfect even at very low speed.
Finally the Sport version, with a blue cap; the engagement speed drops some more, stabilizing at 5kms per hour. But above all it offers a power boost at low speeds and it is useful to connect USB charging devices, such as those on the market, and keep your phone or your tablet in power.
Well, after this long presentation, we can turn on the spotlight on the road test. This is even worse as a metaphor, uh? Sorry, I’m out of shape….
A dynamo has a simple working (in its use, I don’t mean the technique): the faster you go and more energy you get to charge the lights. But to me the efficiency at 30 or 50 kms per hour is relatively important. All right, especially downhill is important, because the speed increases and you must have a good road vision. But I wanted to investigate low-speed performances, a field where hub dynamos show an incredible efficiency.
I did not perform comparative tests or used some equipment to measure amperage, watts and so on; in this website and in the internet there is already extensive documentation and then, you know, I look forward to the practical aspects of the tests. I try to answer the questions that every standard cyclist asks and in this case the question is: can I light up the road with this little dynamo? Yes, a lot; even at a very low speeds, without almost perceiving friction and carrying just few grams, lights not included obviously because it depends from the chosen lights.
I often cycled at speeds below 20 kms per hour, lowering it almost to the limit of balance on some climbs, just to find out how much light I could generate. Always more and more than necessary. For photographic needs I lowered the light, pointing it to the ground: here below there are some motion pictures (as you can see…) at the ridiculous speed of 9 kms per hour. And, even if at night, the park used as a location is in any case illuminated, and this confuses the view.
Hereafter, still at speeds below 10 kms per hour (I used the o-ring more often) and stopped with the condensers provided with the lights on.
I apologize for the low quality of the pictures, but neither my equipment nor my photographer’s ability combine with the images at night. But I counterbalance with my long experience in using dynamo lights, because even if I don’t install them on my bikes, I handled lots and lots of bikes and other bikes on which I installed non-battery lights.
The comparison with any rim dynamo always gives this little Velogical an advantage; the comparison with the hub dynamos is lost only if compared with some mythical figures, such as the Son, which floodlights even if you only look at it. But here we have some advantages that a hub dynamo does not have. Not actually the cost, because the Velogical is not really inexpensive, it costs around 150 Euros to which you must add the lights’ expense, but this common to any hub dynamo.
No, here we have a considerably lower weight. Sure, you could object that a hub dynamo must be heavier just because there is actually the hub. It’s true, but between a lightweight wheel with a high quality hub and a heavier wheel (without forgetting that working on bearing maintenance on some hubs takes a very long time, requires specific tools and not all of them have an adequate smoothness), I always choose the lightweight wheel and the few grams added to the frame by this Velogical dynamo.
The wheels complete with dynamo, I mean nice and ready, are not very popular and the cheaper ones are easier to find. With performances, both energetic and dynamic, not really exciting. It is indeed a common practice to buy a hub dynamo and then assembling or have the wheel assembled by a mechanic, in the latter case with a legitimate additional cost. And always carrying the extra weight, even when we could do without the dynamo. On the contrary, the installation of this rim dynamo is very simple, within reach of any bricoleur who has less than half an hour available. And the instructions provided are sufficiently clear, in English language but understandable also by those who are not so familiar with across the Channel language.
And mark well, I am comparing with the hub dynamos, because in respect of any rim dynamo there is no match, Velogical is alwaysthe winner. Maybe only the B&M Dymotec 6 can be competitive at low speeds; it’s been too long since I used it and so I might be wrong, but at very low speed the Dymotec could also be leading. But at the price of a greater resistance and, let’s say it, it’s not so pretty to look at…..
The test, empirical but indicative, of Velogical effectiveness was of the condensers’ charging. A few hundred meters and I already accumulated sufficient energy to keep the condensers in operation for the prescribed four minutes.
The amount of light produced – of course the quality of the light also counts, but it must be properly powered, otherwise you can have the most efficient light in the world but the road stays dark – is more than abundant to illuminate our route, as well as make us very visible even by large distance. I cannot give my opinion on the ability to recharge electronic devices, as I did not tested directly this aspect. And although the trial version is not the best one for this use, from what I have seen I do not doubt it will be really effective.
I can give my opinion on the waterproofness and its efficiency in the rain, because accidentally I found myself in a heavy, violent and sudden rain during a test run. No slip of the o-ring on the rim (I remember I used a bike with disc brakes and a specific rim, therefore without braking run; the grip is harder), no tension drop, no infiltration. I cannot say the same for the front light, but it’s not a problem, as it is a model which is getting on in years, which has complained of some infiltration and condensation.
Although in the rain it has proved not to lose functionality, it might be a good idea to offer a small protection to be mounted on the plate, shaped like the dynamo, to protect it from water and mud shot from the wheel. As they used to do before, especially on French bikes.
In this short video I enclosed some sort of situations during urban routes; always at low speed, never exceed 25kms per hour in the accelerations and uphill I pedaled to the limit of balance. Because, as mentioned earlier, I was interested more in seeing it in action at low speed than at 40 kms per hour. And then who is pedaling all the time at 40 kms per hour? Not me…
And now the conclusions. I start from an evaluation of the purchase price. High when compared to other rim dynamos. But this little Velogical does not have to compete with them: it’s a good alternative to the hub dynamos, and if defined in this way, the cost is reduced. Because there is no need to add the cost of the rim and the radial.
And if I compare it with a hub dynamo, I must go back to the weight and the ease of assembly, and in both cases Velogical is the winner, at least if somebody, for the second hypothesis, has the wheel assembled. In addition to the overall weight, I also note that in case of a hub dynamo, I carry that weight on my wheels, on the hub and not in the periphery, but still on the rotating mass. And I have a particular idiosyncrasy for heavy wheels…
I did not measure the energy efficiency with appropriate tools, but it’s not serious. At the end, what is important is to know is if lights up or not, if it’s workable or useless. Tables and charts can be found in the website for those who are interested, I aim at the practical aspect. And here the little Velogical has several points in its favor. Few push thrusts and you already have enough energy to illuminate the road, the speed required to get a good view is definitely low, if you slow down more you may fall; the friction is almost completely absent and that minimum present is immediately canceled by the flywheel effect. There is no resistance even in the most difficult climbs at ridiculous speeds, and I cannot say the same about every hub dynamo available on the market, with reference to the cheaper ones. There is no annoying noise in the use, absent with the hub dynamos but present with other rim dynamos, and during the test I only heard an annoying “tick tick”; because I had the adhesive step on the rim in the contact area. As I said above, I used disk brakes, without braking track.
It is suitable for any rim andy any bike, so the diameter of the wheel or the hub typology – aspect of relevant importance – do not matter. Finding a hub dynamo with a passing pin for disc brakes it’s not easy, and when you find it, it’s expensive. And then you are forced into the choice of rays. All these problems do not appear with the Velogical, so total technical freedom, and without any sacrifice on the level of energy efficiency.
I stressed so far on the efficiency at low speeds, but before closing, let me say a couple of words on the efficiency when you increase the speed, or better, only one word: great. The only thing that made me slow down in winding descents was the mounting of the light on the fork head, which, as we know, is an ineffective solution to lighten the roadway in trajectory. Your look, when you bend, always points more inward than where the wheels are, in order to find the right line.
With a fitting different than mine (mine was a “test” one), and of which you have many examples in the photo albums, it’s easy to camouflage cables and wires by easily integrating them on the bike. And in any case, the problem of having the cables in view is a common problem for any dynamo, unless they have some internal passages to the frame. Only the thermistor requires, or may require if you don’t want to stretch the cables, some extra work to keep it close to the dynamo and, at the same time, protect it from shocks. And even if there is a solid cage to protect the bulb, a rock thrown from the road could still damage it.
Who to recommend this dynamo? To anyone like me, who doesn’t like to weigh down the wheel with a hub dynamo and to who, unlike me, needs a strong source of energy always available. City cyclists, tourists, randonneurs who take care of the bike’s weight, off-road riders (no fitting problem even on cushioned forks), technological riders who, willingly or due to circumstances beyond their control, carry GPS and cameras requiring continuous recharging; but not so much to the pure athletes, and not because technical contraindications, as the dynamo is very light but the spotlight are not: and I care about the final weight, when I talk about a pure sport bike. But if I look for equal power, I also find out that, in order to get it with a battery light, I should use some systems that overall are much heavier than the dynamo/LED lights. Considering that with a tightening pair below 4mm. the dynamo is already very secured to the frame, there are no contraindications even for carbon frames. In conclusion, the use is universal, so the question is no longer whether if it is effective or not, because we found the answer: Yes! The question is: “Do I need it?”. Here, only you can answer that.
Have a nice cycling!
Sono Fabio Sergio, giornalista, avvocato e autore.
Vivo e lavoro a Napoli e ho dato vita a questo blog per condividere la passione per la bici e la sua meccanica, senza dogmi e pregiudizi: solo la ricerca delle felicità sui pedali.
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