When it comes to selecting a speed or cadence sensor for your bike there are several options to choose from. You can find sensors from the brands themselves (Garmin, Polar, etc) that will have specific connectivity for their devices, not in terms of only serving their brand, but for the type of standard they use (i.e. ANT+, Bluetooth or even W.I.N.D.). When it comes down to it, we're talking about a very simple device so, beyond aesthetic differences, the features you can have with all of them will be the same. What does Wahoo Blue SC offer, unlike the latter? Its dual connectivity.
The Blue SC transmits speed and cadence data to any device with ANT+ or Bluetooth Smart connectivity, and does so simultaneously, so you can pair your Garmin cycling computer or watch via ANT+ and record your route on your phone as well if you connect via Bluetooth, for example.
As you know, I always like to specify the origin of the test devices, to eliminate suspicions of "purchased" tests. In this case the Wahoo Blue SC was purchased directly from the store and was not loaned by the manufacturer for testing. In fact, it will be permanently installed on one of my bikes.
If you like the work I do and want to support the web, you can buy the sensor through Wahoo on your website or in one of the Amazon links that you can find further down This way you can contribute to the expansion of the web and the purchase of new devices without costing you absolutely nothing.
And once that's all cleared up, let's get down to business!
The Wahoo Blue SC is presented in a box where the company colours of blue and yellow predominate.
On the back you will find information about the product and what it can do, everything is quite detailed, and in the image you can already get an idea of where the sensor will be installed.
The opening is done by pulling the box to the right. It has a system that does not allow to finish taking the box out. The sensor is well anchored to the cardboard and the presentation is really good.
Let's put the box outside and let's stick to the interesting stuff. And inside the interesting stuff I've got these two little manuals. As you know, once you've read this test, you can put it in the same place as the box (in a closet or in the recycling bin), because it's not going to be useful for anything at all.
The content is limited to the sensor, the two magnets (one for the connecting rod, one for the radio) and the sensor fastening system, worthy of the most advanced aeronautics company: two plastic flanges or an elastic stretch. If simple solutions work, why make life difficult for yourself?
This is the sensor. In the area of support with the bike has a rubber to prevent both the frame can be scratched, and prevent the vibrations to move from its position. You can see that consists of two parts, on one hand the main block, which houses the electronics, antennas and the cadence sensor, and on the other an arm that is used for measuring speed.
The Wahoo Blue SC uses a CR2032 button cell battery, which Wahoo claims will have a life of 2 years. On the speed sensor arm you can see the logos of the two types of communications it supports: Bluetooth Smart and ANT+.
And now we're going to put it back, which is the bike.
The installation of the Wahoo Blue SC is simple, but you will need five minutes and a tool. In order to get used to its simplicity, the most complicated part is to remove the pedal from the crank, so that you can insert the magnet of the cadence sensor.
The first thing you need to do is to place the sensor on the bike, on the rear tie rod on the side opposite to the transmission (or you can place it on the transmission side and let it fly off on the first pedal, as you prefer). The same sensor is used to measure both the pedaling cadence and the wheel speed.
You can attach the sensor to the frame in two different ways: with a rubber band or with two plastic flanges. Both options are included in the package itself, so you can choose which shape is more comfortable for you. The advantage of the rubber band is that it would allow you to remove it from one bike and mount it on a different one in no more than 5 minutes.
Once you have the sensor in the frame, the next thing you have to do is to place the magnets. First we can place the crank magnet, for which you must remove the pedal and insert the magnet through the crank. So that you can calculate the placement point there is a small mark that you can find on the sensor itself, as you see in the image. The crank magnet must have a separation between 1.5mm and 3mm for proper detection, so you simply have to tilt the sensor towards the crank if it is too far away.
The next thing you have to mount is the magnet on the rear wheel (or on the front wheel, but maybe you can't get Wahoo to detect it...). It is composed of two parts, a plastic bracket with a rubber to fit the spoke (valid for round or flat spokes), and the magnet itself that is placed on the bracket by tightening it with a screw. Again, the point of placement will be on the mark that you can find at the end of the "leg" of the sensor. The separation distance is the same: 1.5-3 mm. You can bring the sensor closer to the wheel by loosening the screw on its side. When released, the arm can be moved to adjust it correctly.
Once the sensor and the two magnets are mounted, the work is done. You can use the Wahoo application to check the correct functioning of both sensors.
And when you know you have speed and cadence readings, it's time to pair it with your cycling computer or watch. And remember, the advantage of Wahoo Blue SC is that you can connect via Bluetooth and/or ANT+, and simultaneously.
The next thing you should do is choose the way you want your cycling computer, watch or application to calculate the speed. You can measure the wheel circumference and enter the measurement manually or allow automatic calibration via GPS. But all this depends on the device you're using, and here the configuration of Wahoo Blue SC has little to do with it.
When you have the sensor correctly installed, all you have to do is pedal and forget about everything else. When you pair it up, you will have information about your pedaling cadence and the speed at which you are riding.
The first thing that the Wahoo Blue SC allows you to do is to control your pedaling cadence. The recommended cadence is around 90 rpm, because it is the most efficient cadence for flattening. When you are climbing, this recommended cadence goes down to the range of 70-75 rpm. These figures are not counted by me, but have been obtained in several studies made by people much more competent than me. They are related to the central nervous system.
Then every cyclist may or may not agree with this recommendation, since for example there are cyclists who ride very comfortably at higher cadences, but at least what can be guaranteed is that a high cadence causes less muscle fatigue.
In the case of triathlon it is somewhat more complex, as the cadence during cycling can affect the cadence during running. Some people modify the cadence during the last few meters to adapt more to their running cadence and not leave T2 totally out of step. But I repeat, every cyclist is a world and it is best to try different cadences taking into account your particular preparation and the distance of the event in question.
If you don't want to pedal and you want to connect the electric motor hidden in the frame, the speed will still be shown on the screen even if you don't pedal, but the cadence will obviously be 0.
The main advantage you have with the speed sensor is that speed changes are much more reactive than when the data comes from the GPS. In addition, in areas with complicated coverage (vigilant, MTB users) or when passing through tunnels you would lose the speed data. Not only would you be left without information regarding your current speed, but it could also affect the total distance travelled.
In this graph you can clearly see the effect. The yellow line shows the speed graph obtained thanks to the Wahoo Blue SC, while the blue line is GPS data. The development of both graphs is very similar, and in fact the final distance marked is exactly the same. But for example, when there has been a complete stop, the GPS has never reached 0.
If we enlarge the graphs we can clearly see the differences in both cases. The GPS graph has the speed much more filtered than when the data is taken directly from the wheel magnetic sensor.
But where the lack of reactivity can be most annoying is in moments of constant braking and acceleration (whether due to obstacles or for any other reason), not because you don't have the real data at that moment, but because it makes you doubt whether the GPS is recording correctly or not.
And in short, as data addicts that we are, we prefer a graph that shows us reality to one where the data is filtered, as in the image above, where the line followed by the GPS is clearly the average of the different speed changes.
Of course, at all times we will have cadence information recorded, information that you can use to, for example, compare it with speed, power or height and determine your ideal cadence on the flat or climbing.
All this data is collected regardless of whether we are training outdoors or indoors, and perhaps where the speed sensor is most important is in roller training when measuring speed and distance.
Okay, the speed and distance recorded depends entirely on the development chosen and the resistance of the roller. Varying this data is as simple as reducing resistance and increasing development, but it can be a very important data for some people in their indoor training, especially for cadence exercises.
Speed and cadence sensors are quite common, and have been for a few years now, not only for when you are training outdoors, but also for your roller training. And I can't really think of any reason why you would want to do without one, as the information they provide is quite useful in the development (and analysis) of your workouts.
If you are interested in adding a cadence and speed sensor to your bike, the Wahoo Blue SC option is quite solid. Not only because of its simple installation (the most complicated thing you have to do is to remove the pedal with an allen key or a wrench), but mainly because of its dual connectivity. Thanks to this detail you can simultaneously connect the sensor to your mobile phone and your watch or cycling computer, or make sure that if you change devices in the future your sensor will still be fully compatible.
On the contrary, if you already have such a sensor on your bike, even if it doesn't have dual connectivity, it wouldn't make much sense to replace it. You won't find improvements between one device and the other. The only reason I always recommend the Wahoo model is because it offers both connectivity options. I think this possibility deserves the extra expense compared to a sensor that transmits only through ANT+, especially for the future.
However, if you're sure you won't need Bluetooth connectivity, you can also take a look at the Garmin sensor below.
Did you like the test?
I hope this test has been able to clarify all the doubts you had about the Wahoo speed and cadence sensor. Usually these detailed analyses take many hours of work. Besides, you know I am available to answer all your questions in the comments you can find below these lines.
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Buy Wahoo Blue SC
Do you want a Wahoo Blue SC on your bike too? Well, it's very easy to get it and its price is not at all crazy. You can buy it directly through Wahoo on your website There are two models referenced, but the only difference is the graphics on the sensor. Make sure that this is the second version, because the first only had Bluetooth connectivity.