As early as December, I started using a little red box with my original Peloton bike. That little red box did exactly one thing: broadcast my power, cadence, and speed via Bluetooth Smart to third-party apps and watches like Zwift or a Garmin watch. Intelligenate’s DFC unit is meant to be a set and forget about the sort of thing. You just plug it into your Peloton Bike and it will re-broadcast your power and cadence numbers to anything you want. This is noteworthy because neither the Peloton Bike nor Bike + have built-in data transmission of your power or cadence.
For many families who own a Peloton bike, that means you can’t use it with platforms like Zwift or TrainerRoad, without installing third-party pedals, which clearly adds significantly to the cost of the bike. Sure, you could load those apps on the bike, but you actually couldn’t access that power data. But … now it is possible.
I’ve been using this device for about four months now and it’s honestly one of the few perfectly perfect devices I’ve ever tested. It just works. That said, keep in mind that the unit I’m testing is technically a prototype, and also slightly different from the final product (which has more ports, particularly USB-C ports for the Peloton Bike +).
Now we’ll keep this post quick because … well … it should be quick – it’s not complicated.
How it works:
DFC stands for “Data Fitness Connector”, and the little red box is smaller than a deck of cards. Essentially, the box acts as an intermediary, quietly listening to the power data sent from the Peloton Bike’s sensor to the display. Normally this is connected via a simple 3.5 mm cable that you plug directly into your screen. However, the DFC comes with an extra cable, so you plug your original cable into the red DFC box and then plug the DFC box into the display. Then connect the USB cable to the USB port on your Peloton. This is only to provide power, just like charging your phone.
And with that you are done. What’s important about this is that there is no need to install any software or have software (or even hardware-wise) changes on your Peloton Bike. It’s basically like plugging in headphones. Behind the scenes, the DFC box decodes the power and cadence signals normally sent from the bike to the display, and simply retransmits them via Bluetooth Smart using the standard Bluetooth Smart power meter profile. This allows you to easily connect it to apps and devices. By using the USB port on the back of the device, you don’t have to worry about the battery life, as it will remain charged forever.
So once everything is connected, you can search for and find a Bluetooth power meter. For example, here it is connected to a Garmin FR745:
And here’s the data streaming. From the user’s point of view, this is identical to any other bicycle power meter. It’s all the same. Just start your indoor ride on your Garmin / Polar / Wahoo / Suunto / whatever, just like you would for any other trainer ride.
And here’s Zwift on my iPhone connected to it:
It broadcasts the same data as Peloton itself, although you will see very slight 1-3w differences in some cases. Below is not really one of those cases as my watch is set to 3 second smoothing and the Peloton bike is not.
But looking at the data itself, I’ve recorded a workout both within the Peloton Bike and on my Garmin, and you can see that the data is pretty much the same except for some very minor second-to-second differences by a watt or two:
This includes both power and cadence data and also speed, although most cycling training apps will ignore / ignore the speed (as in Zwift or TrainerRoad). The system supports two simultaneous Bluetooth connections, so you can pair it with an app such as TrainerRoad while simultaneously storing the data on your watch.
For Garmin and Polar users, this is notable from a training load standpoint, as there was previously no way to get power data from a Peloton Bike to your watch for training load and recovery perspectives. And I know some of you think “no serious cyclist” would ever use a Peloton bike, but the reality is the opposite. Far too often people think about training platforms. As long as you apply load (a stimulus) in an organized and structured way, you will gain speed. It really is that simple. Peloton also has power zone-based training. You do what makes you happy, as long as you pedal, it is all good.
Whether the Peloton Bike itself is correct or not is a different story. In all my tests comparing the Peloton Bike (original) data to power meter pedals, it tends to read high, usually in the 5-7% range. You can technically try and recalibrate, but I haven’t found that to fix anything (and frankly, I’ve also done calibration runs that make it a lot worse – and without power meter pedals on the bike you wouldn’t know which way made it).
While the Peloton Bike + I have found to be exceptionally accurate – comparable and actually better in terms of accuracy than many of the high-end smart bikes that a typical Zwifter or TrainerRoad user would have in their arsenal. Unfortunately, the DFC is currently not compatible with the Peloton Bike +. That said, they added USB-C ports and other bits to make it potentially compatible later on. But I wouldn’t buy it today until that happens. Whereas if you have a regular Peloton bike, it is fully compatible there.
Geeky stuff:
For those who are a bit more geek, the company has done quite a bit to allow third parties to expand it. So, for historical interest, here are the technical specifications of the business listing:
- Built around the Nordic NRF52840
- ARM Cortex-M4 32-bit processor
- 2.4 GHz Bluetooth 5 transceiver
- 11 visible GPIO pins in a breadboard and IDC compliant layout
- 4 analog or digital pins
- 7 pins that are digital only
- 16 M-Bit QSPI external flash memory
- Two channels for bidirectional RS-232 to TTL / CMOS conversion via MAX3222 IC
- I²C JST connector compatible with SparkFun’s Qwiic or Adafruit STEMMA QT Connect system
- SWD connections on the front and back of the board via Tag Connect footprints
- 20 V max to 3.3 V voltage regulator
- Two 3.5mm stereo jacks connected to each other and to the RS-232 driver / receiver IC.
- A standard jumper allows the transmission of RS-232 data through the connectors
- Two USB Type-C connectors that allow DFC to be in-line with a USB cable operating up to 20V
- With this experimental configuration for use at your own risk, you can branch out and connect the signals present in the USB cable, such as those used by the Peloton Bike +, to the processor.
- Configurable routes via jumper headers and solder pads for USB D +/- and SBU1 / 2
The idea is that this can later be expanded by both the company itself and third parties.
Notably, this device doesn’t have ANT + enabled at this point, but Nordic’s NRF52 chipset they use would allow for that upgrade if they so choose. It’s a software upgrade that the company would have to pay for (they may have already).
Practically speaking, all Garmin devices from about 2017ish and beyond have supported Bluetooth Smart power meters. So any Fenix 5 or higher, as well as Garmin FR935 or higher, will support it. And all Polar and Suunto devices support Bluetooth power meters. Still, ANT + is useful and often preferred in desktop computers over Zwift and other third-party apps, plus older watches and cycling computers, of course.
Packing up:
Frequent readers know that I really like devices that ‘just work’, and this one takes the cake. I don’t have to touch it since I plugged it in in December, and it just works every time – always there, always ready. My watch automatically connects to it when I start pedaling and all I have to do is start a workout on the watch. Not sure what more I could ask for.
The unit costs $ 109, which seems pretty reasonable considering the alternative is to buy power meter pedals from around $ 500 + (and more if you want total power). Using Peloton Bike’s data stream is certainly not as accurate as buying a set of power meter pedals for other apps, so that’s a consideration. For those concerned this will somehow lead to an explosion of inaccurate data on Zwift, the level of accuracy here is really no different from most of the wheeled trainers I’ve tested over the years (which specify + +/- 5%, but are often closer to 5-10%, especially in sprints).
The company is now taking orders on their crowdfunding site, for delivery in early August. Given the shortage and long backlogs for computer chipsets at the moment, they (like any other tech company) have identified that as a risk. The other risk is that Peloton could update the data stream on their bikes to specifically break this down. The DFC unit can be upgraded via software in case something changes. That said, I would be extremely skeptical if Peloton can actually do this on the original Peloton bike. It would certainly have this capability on the Bike +, but after taking the original Bike apart, the sensor system is only connected by an analog 3.5mm cable, which is highly unlikely to allow firmware updates. Furthermore, that would be a huge risk for Peloton to upgrade that part on 1.5 million bikes just to ‘break’ a few boxes.
So, considering it’s working great for me on the original bike today, I went ahead and pre-ordered it already. If they find compatibility with Bike +, I’ll buy another one for my Bike + too.
With that – thanks for reading!