The Chainlink

Product Review: PowerPod Power Meter

By Jeremy Bloyd-Peshkin

When I first started actually training for riding, everyone said to get a power meter. It was the holy grail of cool gear, and the science to back up why using one made training more effective was sound. I loved the idea and was about to get one until I realized the cost involved - a typical power meter costs as much as a high-end groupset. Yikes. Enter the PowerPod, which retails for $299 and can be swapped between bikes. Velocomp, who make the device, claim that it’s as accurate as a traditional power meter, far more convenient, and at a fraction of the price. So is it as good as they say? 

Disclaimer: The PowerPod I tested was provided to me at no cost, but the expectation was that I would give my opinion honestly.

First things first - why would anyone want a power meter? In order to train effectively and efficiently, it’s pretty darn handy to have a complete picture of how hard your body is working. Although it’s perfectly fine to gauge a workout by your perceived exertion, it isn’t very accurate. A heart-rate monitor is a common tool to have, since it’s inexpensive and does give a good picture of your performance from a cardio standpoint. Knowing your maximum heart rate, how hard were you working and for how long? But although they’re related, how hard your heart works and how hard your legs work aren’t exactly correlated. And their relation changes as you train - even over the course of one workout. Enter the power meter, a device that tells you how much power you put into the cranks (or don’t in my case). By periodically testing how much power your legs are capable of putting out, you can build a scale by which to determine how hard you can mash when you train. Combine that with your heart rate and you have a pretty complete picture of what’s going on in a workout and a good idea of how to train effectively and efficiently. Of course, I don’t mean to say that any of this is necessary. But it is handy, and pretty cool as well.

A typical power meter measures the force you exert on the drivetrain directly. They come in many forms, from pedals with load cells in the spindles to cranks with embedded strain gauges, and even hubs that measure torque. All of these measure force directly, do a bit of math, and transmit a number in "Watts" to your cycling computer. They’re called direct-force power meters.

PowerPod takes a different approach. PowerPod measures all the things slowing you down - aerodynamic drag, rolling resistance, hills, wind, even road roughness - and calculates it against your acceleration to figure out how much power you’re putting down. It’s a solid principle, but it relies on measuring a lot of factors very quickly, a bit of guesswork, and a hefty dose of math. This is often how data collection is done in a lab environment, but does it work on the road?


The device itself is, well, a small pod. It comes in a box with a USB cable (conveniently, micro-USB like most other devices), a mount, and a single sheet of instructions consisting of large pictures and very few words. All I needed to provide was an ANT+ speed sensor on my bike. The pod itself mounts on any standard GoPro mount, though it comes with a very nice slim one designed to clamp around 31.8mm bars. The provided mount is slightly shorter than one for a GoPro (so a camera won’t fit), but this means that it’s very easy to remove and re-attach the PowerPod in exactly the same alignment every single time. I’ll get into that later, though. I mounted everything to the bars, spun my rear wheel to wake up the speed sensor, and pressed the one button on the back of the PowerPod. It woke up, paired with the speed sensor, and started blinking at me to take it for a ride. So I paired it with my Garmin (it showed up as a power meter) and pedaled away. The PowerPod’s first ride is supposed to be for calibration purposes, meaning it should be on more-or-less level ground and smooth-ish pavement with minimal stops. In Chicago, the first of those three criteria is easy to meet and the last remedied by riding late at night. It takes five minutes to calibrate, and gives a progress indicator on the head unit by displaying a power value from 0W to 100W. When it gets to 100W, it’s done and starts displaying normal power numbers. After a long enough period of inactivity it powers off and can be woken up again by pressing its button.

The interface is very simple. It has a button and a light and a USB port and that’s all you get. Press the button once to turn it on. Press and hold it to pair to new sensors. Leave it alone and it turns off. As much as I like cool tech, I don’t like overly complex things on my bicycles and so the PowerPod is perfect for me. I push the button, and then forget about it and go ride. That it is entirely unremarkable in use is the best praise I can give - if it were attracting my attention something would be wrong.

Perhaps even more importantly, it gives reasonable-sounding power measurements. I don’t have a direct-force power meter for comparison, though others have verified it to be accurate ±2%. For example, the DC Rainmaker blog, largely known as an authority on power meters and other high-tech cycling-related products, did an extensive test of the first-generation Power Pod, compared it head to head with an array of popular power meter products, and found it to be quite accurate in most paved riding conditions (though in his test it encountered some issues on rough surfaces like cobblestones). Another plus is the battery life is very fair at ~9h.


The real fun comes when you plug it into the computer post-ride. Download the Isaac software package and you gain access to all the fun internal features of the PowerPod. It’s capturing huge amounts of data as you ride, don’t you want to play with it?

 

It turns out that the PowerPod doesn’t just pair with the speed sensor on the bike, it pairs with every nearby ANT+ sensor. In my case, that includes cadence and heart rate as well. The wind sensor that calculates your drag coefficient can also reassure you that it isn’t just that you’re slow, but you can blame that headwind as well. When paired with a cadence sensor, it calculates how efficient your pedal stroke is. And using accelerometers, it can figure out when you’re coasting, braking, and standing to get an idea of your overall efficiency as a rider. There are also countless configuration options. The profiles it builds while calibrating on the bike are visible and editable. And if you’re willing to go for a ride in known conditions, you can use the Isaac software to further refine that profile and end up with an even more accurate calibration.

The PowerPod also supports mounting on multiple bikes. If when you mount it on a bike with a different speed sensor it re-calibrates, builds another profile, and then behaves exactly as it did before. Switch it back to the other bike and it switches to the profile that matches the speed sensor it’s reading. In practice, I’ve had some issues with smooth transitions bike-to-bike. It often takes 5-10 minutes to start outputting power data when I switch bikes, though it’s solid after that and when examining the data later I’ve always found it to use the correct profiles. It’s very important when switching between bikes that orientation of the PowerPod itself is consistent. If it’s tilted on one bike, it must always be tilted that way or the data will be skewed. This is easy with the stock mount, since it’s shorter than a standard GoPro mount the locating tab on the PowerPod can be used as a stop to make sure it’s the same every time. On a normal GoPro mount, you have to use a straightedge to make sure the front of the mounting tabs are flush. My solution was to attach the PowerPod to a standard GoPro mount and then use GoPro’s handlebar clamps on my bikes so I can just clip it in and out. It’s worked a treat, though the mounts are a bit pricey.

Since everything was working swimmingly on my road bike, I decided to try to break things by mounting the PowerPod on my cyclocross bike. Velocomp recently released a firmware update for the PowerPod that gives more accurate readings when on gravel, but gravel is a whole different beast from mud, sand, and rough grass. I bolted it onto my bike, rode over to the park, and rode the calibration doing laps on the grass. The PowerPod gave me numbers, but they were all over the map so I returned home and messed with the profile on the computer a bit before heading back out for another test. A few more rounds of this combined with coast-down tests and a stopwatch and I arrived at what seemed to be a reasonable profile. Again, let me state that I don’t have a direct-force meter to use for comparison, so I was just going for numbers that seemed within the ballpark. What was far more important to me is that the numbers I saw were consistent from lap to lap, and they were.

So I took the PowerPod to an actual race at Melas Basin, the 10th race in the Chicago Cross Cup series. Comparing notes post-race with others in my category who had power meters, the numbers were fairly close. The PowerPod was tending to read low, but it had no way to determine when I was on grass or in sand so that’s more than fair. It also survived getting stuffed with sand during a pile-up shortly after race start, so that’s a win too.

So what’s the verdict on this thing? Is it possible to get good power data for less than half the cost of the next thing on the market? Yeah, sure. The PowerPod proved to be a consistent (and surprisingly durable) performer in a variety of conditions, some of which it was never intended for. It is arguably not the most accurate system out there when faced with off-road and other rough surfaces, but it’s consistent and as a training tool that’s the only thing that matters. I appreciate its simplicity and reliability, and though I had a few small issues with switching it bike-to-bike I never encountered anything genuinely frustrating. If you’re looking for dead-nuts accuracy regardless of road conditions or the ability to measure power during a 24-hour race, this is not the device for you. But if you’re looking to train with power and don’t want to spend half the price of your bike on a load cell, I’d definitely recommend the PowerPod.

PowerPod, $299 Retail

https://powermetercity.com/product/powerpod-power-meter/

Jeremy Bloyd-Peshkin is an engineer, machinist, and racecar driver from Chicago who really doesn't care how many wheels a vehicle has as long as he can race it. He credits Flint's leaded water for his trust issues with freewheels, and can often be found riding brevets fixed-gear, attempting to unicycle down stairwells, or inventing new and strange forms of profanity. He's probably drinking coffee right now.

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