NPE Runn Treadmill Smart Sensor: Everything you need to know

A few weeks ago when Zwift announced their new running track within Watopia, a bunch of you were curious about the NPE Runn device I showed briefly within that post. But then yesterday Zwift sent an e-mail out to about a third of a million people talking about the Runn, and a cruise ship’s worth of you migrated here for questions. So ask, and you shall receive!

Runn serves exactly one purpose: It turns your dumb treadmill into something a bit more bright. The small pod simply attaches to your treadmill and then broadcasts itself as a smart treadmill, allowing apps like Zwift to get your current speed as well as cadence. It even transmits the treadmill’s incline too, though no apps yet take advantage of that today.

For those unfamiliar with North Pole Engineering (NPE), my guess is that if you went into any major chain gym in America, you’ll probably find NPE devices hidden away behind the scenes. They’ve become one of the core players in the fitness communications realm on things like ANT+ & Bluetooth sensor connectivity and bridging in gyms, but also chipset/communications work and solutions behind the scenes for companies like Wahoo, Orangetheory, Kinetic, Scosche, Garmin, and many more. You’d probably be surprised how many sports tech paths lead to this Minnesota company. But this product is all about the consumer, not the industry.

Finally, note that I did buy this unit myself. As noted I had previously beta tested a prototype of the Runn over the course of the fall. And then I recently bought a final version at full retail price ($99) for myself and the DCR Cave. That’s what you see here. As always, I don’t do sponsorships of any type with companies that make the products I review. If you find this review useful, hit up the links at the bottom or on the sidebar to help support the site.

What’s in the box:

NPE has never exactly been known for their swanky box or packaging designs, and the Runn continues that trend. Their mantra would probably be “Just the facts, ma’am”. The box simply says North Pole Engineering on one side, and Runn on the other.

 

Crack open the box flap and there’s a simplistic note sitting atop it:

That note reminds you to fully charge the unit up before first use, as well as their e-mail address in case you’ve got any feedback or issues.

Below deck there’s a tray of stickers. This box is basically my toddle’s dream: Two different sticker packs and something with blinky lights.

The red ones are double-sided tape and used to attach the Runn device to your treadmill, while the silver stickers are used as mini light reflectors on the treadmill belt itself.

 

There’s also a short manual with the handful of steps you’ll need to know.

Then, of course, there’s the device itself, which is technically two parts – the pod and the pod holder.

Plus the micro-USB charging cable:

The pod easily unclips from its holder, and if you look at the underside of it you’ll see the two little optical sensors at the top (right picture, upper edge). It’s the measurement of the time it takes for the little sticker to go between the two points that’s determining the speed. Since this distance is known, figuring out the speed is easy.

 

We’ll talk more about these later. Then on the back you’ve got the micro-USB charging port under a protective rubber flap and the single power button:

With that, we’ve exhausted all there is to exhaust in this box.

Installation:

We’re gonna keep this section short. Because frankly, it’s easy and short.

If you didn’t charge it yet out of the box, now’s a good time to do so, unless you plan to simply leave it plugged in all the time.

Now, find your treadmill. I suspect this step will be easy. Next, you’ll need to find a smooth spot on your treadmill to mount the unit. Grab the mounting piece and find a spot big enough, ideally not near where you’ll clip it while running. In my case, I went towards the very back. As a pro tip, you’ll want to ensure you’ve got a spot that’s smooth and ideally doesn’t have any curvature or slant to it.

 

For example, you can see how on my treadmill there’s a slanty part that looks like it got the Chicken Pox. That ain’t no good! Sure, with enough creativity you could make it work (I did briefly on the earlier prototype), but it won’t be super stable. Physical stability is ideal for accuracy and stability of your pace.

Once you’ve got your spot, place the tape on the back of the NPE device, and then remove the other part of the double-sided tape. Plunk it on your spot:

 

And then attach the unit to it. You’ll want the pod a bit under 1cm from the belt, so pretty darn close. I find it useful to put the treadmill on a low speed while doing this, so you can hear in the event it rubs anywhere.

Next, you’ve got these little silver stickers. These are what the unit uses to reflect light off to measure speed. You need a minimum of one, and ideally a maximum of 2 or 3. I used one during most of the prototype phase without issue, and then also used 2 and 3 with the production device. I didn’t personally see much of a difference in responsiveness, but if you’re mostly at slower speed, it’ll make more of a difference.

Remember, it’s not measuring the time between the stickers, but rather the time it takes a single sticker to pass from the 1st optical sensor to the 2nd optical sensor. The more stickers you have means there’s more data points to gather speed upon each rotation.

In my case my treadmill has this pattern on the belt. While that’s great for traction, it’s horrible for stickers. That means that in some cases the stickers would last about 4 rotations before flying off. I had a bit more luck later by really cleaning the sticker spot first, and then pressing the crap out of the sticker into the groove.

Instead what you can just as easily do is take a little bit of white-out and make a mark as well. That works just as well for me and NPE says that’s perfectly good too. It basically just needs a white-ish surface to reflect the light off of:

Finally, go ahead and plug the device in. It’s got an internal battery that lasts 10-12 hours according to NPE. I never used that bit. I just left it plugged in the entire time. The cable NPE provided would probably drive a large pickup truck, since it’s a bit short. But since it’s just a standard micro-USB cable, I just grabbed a longer one out of the bin of 148 micro-USB cables I have. Plug it in and then forgot about it for the rest of your life:

 

Finally, you can use NPE’s GymTrakr app to do quick tests of the sensor, as well as even record workouts and save history from it. It wasn’t something I spent much time testing though, as like many sensor-focused apps from sensor companies, if the device works properly, you’ll probably be using other 3rd party apps 99% of the time anyway.

With that, done.

Usage with Zwift:

I’m going to mainly focus on Zwift here, since I’m pretty sure that’s what approximately 99.3% of you will use it for. But it’s not technically limited to Zwift. In fact, that’s sorta the beauty of following industry standards – it’ll work with any apps that support these standards.

The Runn currently broadcasts three core values:

A) Your current pace
B) Your current cadence
C) The treadmill’s current incline

It does this on two protocols:

1) ANT+ FE-C (for fitness equipment control)
2) Bluetooth FTMS (for fitness equipment control)

In addition, it supports the broadcasts itself as a standard running footpod, it’ll show up on both ANT+ & Bluetooth Smart, allowing you to pair it to virtually any Garmin/Suunto/Polar/COROS etc running or multisport watch. That’s because none of those watches support FE-C or FTMS, so you wouldn’t be able to use it with them directly yet.

However – in my testing this function wasn’t showing up. NPE says (after publishing) you need to have the unit either plugged in via cable, or double-tapping the button. I had the unit plugged in, but I’m not sure if I tried double-tapping before or after pairing. At this point I’m on a trip to the Tour Down Under, so will have to check again when I get back.

Go ahead and crack open Zwift. It doesn’t matter what platform you use – it supports them all. I’ve tried it on Apple TV (Bluetooth Smart), Windows PC (ANT+), iPad (Bluetooth Smart), and iPhone (Bluetooth Smart). You’ll see the option to switch Zwift into the ‘Run’ mode if that’s not your default.

Next, you’ll see the Runn sensor listed automatically as a ‘Run Speed’ sensor. In my case, I had both the production unit you see as well as the prototype nearby. You’ll notice how the icon is technically a little treadmill, and not just a plain footpod. That’s because it’s using that fitness equipment protocol instead of the footpod one.

Once you’ve selected that, you’ll see the Runn sensor showing. I turned on my treadmill so I could show you the speed bits, so you see it showing 6MPH there (if you have Zwift set for non-Americana, it’ll show metric).

However, we’re not done yet! Next, let’s pair up the cadence side of things. You’ll see the option there, simply select it and tap OK. Because I was using an iPhone for these screenshots, you’ll see that it shows just the Bluetooth Smart connection. If using an ANT+ enabled computer/etc it’ll show ANT+ too.

And with that – you run. It’s frankly as simple as that. Below you can see my pace showing up on the left side and upper middle (8:01/mile and 7.5MPH), as well as the cadence (Steps/Min at 172). Cadence is using the vibrations of your (or my) gigantic footsteps through the belt and shaking the treadmill as I do. Given how sensitive accelerometers are, this is probably equivalent to the ease of detecting an 8.0 earthquake.

A couple of weeks back when I did my first Zwift structured track workout I used it then too – and it worked great. In that case I was using it with ANT+ and my laptop precariously perched above the treadmill on a cabinet. I did see a few dropouts there, but in talking with NPE they suspect that might be more to do with the specific ANT+ USB stick I was using and the wonky location of my laptop. NPE says they’re looking at a few options there as well though if they see it become a more widespread issue.

One of the fascinating things that the Runn will show you though is just how accurate (or inaccurate in my case) your treadmill is. Unless a sticker flies off, the Runn is a fairly simplistic device in terms of how it works. It’s gonna show the correct belt speed. The question is: Does your treadmill show the right belt speed?

Of course, treadmills are known the world around at being inaccurate or variable, and mine is no exception. For example, at relatively steady and long-run type paces, my treadmill is pretty much spot on with no issues. But, when I ramp up the pace and start throwing down intervals like the above, my treadmill has a rough go of life.

The actual belt speed wobbles quite a bit. And it’s something you can absolutely feel (and see in the charts above). My treadmill has quick selection options along the side, enabling me to quickly tap a given speed (shown in KPH here) and it goes straight there within a few seconds. But what I felt, and Runn confirmed in data, is that the speed oscillates and meanders quite a bit. Upwards of a few KPH easily at these higher speeds. I’d then have to manually put the treadmill faster to get it to the target speed.

So while some may prefer ignorance is bliss on this sorta thing, having Runn is great here, because it allows me to ensure my intervals actually hit the exact pace I want – not some less useful slower (or faster) pace.

Now as mentioned earlier, the Runn transmits your incline, and even allows you to zero it out with a calibration option too, in case this is somehow out of alignment. However, no apps that I’m aware of today actually support this feature. And even once implemented the main usage would probably be around displaying incline difference reminders.  Note that you can change the incline zero (baseline) via calibration via a simple button procedure. I did this for my first unit but didn’t see any meaningful difference on the final production unit with my specific treadmill.

That’s because the unit doesn’t integrate directly with the treadmill. Meaning, it won’t change the incline on your treadmill per what Zwift (or any other app) says it should be. This is mostly because treadmill companies are super hesitant to let 3rd party companies or apps change the treadmill incline or speed (the primary concern is speed). In fact, NPE actually has gym modules that integrate better with treadmills – though unfortunately mine doesn’t support that module port type (Random backstory: Four years ago Wahoo partnered with NPE initially for this module, and then sold it all back to them, so it’s all NPE now).

In any case, once you’re done with your workout, then like normal you’ll get all your stats on your run just as you would have with a footpod.

I’ll add some more accuracy comparison charts here over time, but honestly that’s kinda like comparing the weather on your phone saying it should be raining, versus just looking out the window and seeing it’s not yet raining. Using a footpod or a wrist-based accelerometer will introduce some variance. For many people – it’s stable enough. Whereas with this, as long as you’ve got your stickers (or white-out) in the right spot, there’s very little chance of measurement inaccuracy.

Treadmill belt speeds can and do shift slightly within each ‘rotation’ of the belt. It’s one of the arguments that Stryd, for example, has made on why a footpod might be a better fit for some people indoors. But Runn gets around that by simply allowing you to add more stickers, which increases the sampling rate per revolution. I think it’s far less likely that within that split-second gap between the sensor detecting the next sticker that you’re going to find an appreciable difference in speed, versus the far more common scenario of just having a footpod that’s not perfectly calibrated at all the speeds you’re trying to track (most footpods become less accurate the further away from your calibrated pace).

In any case, at this point, that’s about all you need to know about the Runn.

Footpod vs Treadmill Sensor:

I’ve seen a few questions on comparisons to a footpod, and which one is a better choice. As always, the proper answer is ‘it depends’. For example, if you want to go outside, then no amount of Runn creativity will help you there (ok, I suppose one could get absolutely crazy creative with markings on the ground…but don’t tempt me!). So for that, a footpod like the Zwift Pod or Stryd will be better.

But if you’re focused purely on treadmill usage, then the next question is whether or not it’s a treadmill under your control. If you primarily run on a gym treadmill – this isn’t super ideal, since you’d need to place stickers on it and a mounting pad. On the flip side, if you live in an apartment building with just 1 or 2 treadmills, you could probably get away with applying the stickers, and then instead of using the tape, just use Velcro to be able to quickly attach the sensor to the treadmill (certainly, one sticker strip of Velcro will have to remain). So if you don’t own it, then you’ve gotta balance those aspects out vs just using a footpod. (This is where the previous TreadTracker was great, sadly, it’s been discontinued)

Last then, is the case of owning your own treadmill and deciding whether Runn or footpod is best there. For me, I’m going to go Runn. The reason is simple: I don’t have to dork with it. Just like a stationary trainer or indoor bike, it’s just sitting there ready for me. No charging required (since I just leave it plugged in), and no calibration required.  I know some footpods claim no calibration, but there’s kinda a mountain of people showing that’s not entirely the case.

With the Runn, it’s a very straightforward concept. There’s no need for calibration for most people. It’s just measuring belt speed with two optical sensors. That actually has advantages of the earlier TreadTracker, because that measured it via a small wheel that could potentially see bumps/drops due to footsteps bouncing the belt. With the optical sensor, I haven’t seen that be the case. And of course, the Runn sensor is a heck of a lot cheaper than the Stryd footpod, though, more expensive than the Zwift footpod.

Finally, if in a multi-user situation, then the Runn really excels, because it’s there for everyone. No need for multiple footpods each with their own calibration values.

Summary:

NPE’s made a name for itself in the consumer space by filling these protocol and connectivity niches with reasonably priced solutions. They did it with CABLE, WASP, HeartBeatz, and now Runn.  In all of these scenarios (except for WASP), technology will eventually eliminate the need for this product. And I suspect that’s alright with NPE – it’ll have moved on to the next thing.

With Runn it’s filling the gap of decades of treadmills out there that can’t connect to much of anything. Treadmills that people are highly unlikely to replace. Heck, even boatloads (the vast majority) of brand new treadmills these days don’t transmit pace or cadence on proper industry standard protocols.

I’d love to see a way to mount it underneath the treadmill (to minimize chance of damage), and of course, I can’t wait for Zwift to do something with the incline data. For example, they could show when there’s a mismatch between the prescribed incline in Zwift, and what the treadmill is showing.

In my case, I’m looking forward to the Runn sensor always being there, and just having a high ‘just works’ factor. I’m all about ‘just works’ devices.

With that – thanks for reading!