Bike

Ask a Gear Guru: What Are the Best Power Meters for Triathletes?

For triathletes looking to maximize their bike training, a power meter is essential. We look at the best options.

If you’ve been in the sport for even a little bit, you’ll recognize that the biggest enemy of any triathlete is time. There’s never enough time to get in those workouts, proper recovery, good nutrition, stretching, strength training, injury prevention—not to mention those other little things like time with your family, friends, and work. Because of this, triathletes are always looking for the best way to optimize the time they spend training. For cycling, using a power meter is one of the best ways to get better by eliminating most of the guesswork behind effort. 

What Is Power?

Put very simply, power meters measure the amount of force the rider is applying (torque) times the angular velocity (cadence). This means that the power number you see on your computer is a direct result of literally how hard you’re pushing down on the pedals. With the exception of some microscopically small losses of force through the drivetrain (if it’s wheel-based or on a trainer) or other modes of transmission, what you put down is precisely what you get out. Unlike speed, if it’s windy out, it doesn’t matter; if you’re riding up or downhill, it doesn’t matter; rough roads don’t even matter. And unlike heart rate, there’s no cardiac drift or major effects due to temperature, fatigue, etc. So all of the guesswork that would come with heart-rate or speed training on imperfect places like roads are eliminated with power meters. Most power meters use strain gauges placed in various parts of the pedal-to-tire force chain, but a few use air pressure and other methods. Check out our links below for (way) more on training with power for triathletes.


Related:
Should I Train with a Power Meter?

Power Meters are More Affordable Than Ever—Here’s Why You Need One

A Power Meter Is Not Magic—Here’s How to Use It


But with so many options on the market, what makes the best power meter for triathletes?

It depends. Obviously budget is a big part of it—power meters are not at all necessary for someone looking to do their first (or probably even their second) tri. While there has been news about crazy cheap power meter parts being offered to manufacturers, time will tell if they’re any good or if they’ll make it to market. But budget aside, there are features and functions that make an ok power meter the best power meter for one triathlete and a complete waste of money for another. First, we’ll look at what makes a good power meter the best power meter for triathletes, and then we’ll go through some picks.

What’s The Point?

First, you need to ask yourself why you’re getting a power meter. The most important answer should be “to train more precisely.” After that, you can think about playing on Zwift or trying to hit “high power scores” to compare with buddies. Another good reason is to race better by pacing more effectively and dialing in your nutrition (power can help you determine calories spent!). Not only will your workouts be more precise and quantifiable, but you can determine exact zones for pacing with power as you race in order to avoid blowing up or still having too much left in the tank. Of course, there are other factors to consider when it comes to gauging effort and caloric expenditure on the bike for racing, but a power meter can help. In other words, the best power meter for a triathlete has to address your needs: If you’re going to race with it, be sure it’s not wheel-based and trapped on a set of training wheels you’d never race on. 

Where Will You Go?

Do you have multiple bikes? Do you ride on a road bike some days and your tri bike on others? Do you travel and rent bikes at your destination—be it for races, training camps, or work? Do you ride inside? If you’re only going to use it training indoors, maybe a smart trainer is the best option; if you need to take it outside, then look for something bike-based. If you switch bikes often, maybe look at something pedal or wheel-based. If you travel quite a bit, stick to pedals.

Accuracy Matters, Right?

This is a tricky one. Instincts say that accuracy should always be a priority when choosing the best power meter for triathletes, but actually repeatability matters more than anything else. Even the most accurate power meters in the world need to be calibrated often—due to changes in temperature and other conditions—so if you’re not calibrating properly, accuracy is not super important. In fact, knowing how easy (or not easy) it is to calibrate your power meter is a big draw in which one to buy. 

That said, accuracy matters most when you’re comparing to external numbers from other devices, like in a lab when you’re doing testing. Consistency matters most for one person riding one power meter: If it’s always off by 10 watts, then it doesn’t matter too much if all of your FTP testing, workouts, races, etc. all occur at 10 watts lower than the most precise power meter. It’s the repeatability (via constant and proper calibration) that matters most. If you use different devices often, then their accuracy matters much more.

Power Your Power

This is something a lot of first-time power meter buyers don’t think about, but they should: How does my power meter get its juice? Power meters have traditionally had to be hermetically sealed to prevent the elements from intruding upon the super sensitive electronics inside, and back in the day, the only way to access the batteries buried deep inside was to send it into the manufacturer for servicing. Today, things are better as most power meters have user-serviceable batteries, but some of those batteries run out pretty quickly if you’re riding a lot, and it’s not like they take AAs you can find at the liquor store down the block. So it’s important to note when a power meter has a rechargeable battery (that still lasts long) or knowing how hard/not hard it is to change when the time inevitably comes.

Armed with a little more information on what makes the best power meters for triathletes, let’s take a look at a few picks, based on features and reviews:

Best Value Power Meter For Triathletes

4iiii Precision Power Meter

$300, 4iiii.com

For almost half of some other brands’ offerings, 4iiii boasts a non drive side Shimano 105 crank arm power meter that weighs a ridiculous 9 grams. While this version runs for 100+ hours on a 2032 watch battery (a common battery that your liquor store might actually have), they also make a USB-rechargeable version for $350 called the Podiiiium for those who want to go that route. In both instances, this tiny little power meter add-on (you can also get it installed on your existing crank arm) has a shocking +/- 1% accuracy, which is amazing at any price. 

Best Dual-Sided Value Power Meter For Triathletes

Favero Assioma DUO

$600, Favero.com

In terms of combination portability and functions, the Assioma is tough to beat. With a dual-sided power meter, riders can squeeze every drop of data out of each training session—looking at balance between left and right pedals, smoothness, efficiency, and more. Very cool features like automatic temperature calibration and a light weight at 152g per pedal, Favero packs a ton into a ANT+ and Bluetooth-compatible setup that could easily go for $1,000.

Best Data-Driven Power Meter For Triathletes

Garmin Vector 3

$1,000, Garmin.com

Boasting a sleek and almost clandestine form, this dual-sided pedal system (also available in one sided for $600) gives so much data, it’s almost overwhelming. Using slightly difficult-to-find battery (LR44/SR44) this Bluetooth and ANT+ compatible system runs for roughly 120 hours and weighs in at 158g per pedal. Obviously it links up to the Garmin ecosystem in a heartbeat, and once connected it produces a treasure trove of data like platform center offset to show if you’re putting more pressure to the outside or inside of your foot, alongside other dynamics that show smoothness, left/right imbalances, and even visualizes (with a Garmin device) power phases through the pedal stroke.

Best Indoor Smart Trainer With Power Meter For Triathletes

Wahoo Kickr Core

$900, Wahoofitness.com

This smart trainer is built like a rock—exactly what you want in a wheel-on system that measures power and gives feedback from virtual training environments. Both ANT+ and Bluetooth-compatible, this trainer hooks on to your bike’s rear end to provide you with a super stable (but also easy-to-move) platform to measure watts, do workouts, and more. With an accuracy of +/-2%—pretty much around the industry standard for trainers—there’s a lot you can do with the 1800W max ceiling and 16% simulated grade. Unlike some other brands, expect instant and rock-solid connectivity with devices and virtual platforms.

Best Alternative Power Meter

Velocomp PowerPod Lite V3

$200, Velocomp-llc.com

Unlike the other power meters in this guide, the PowerPod uses a combination of wind sensors, barometric sensor, accelerometers, and a host of calculations to deliver a power reading that’s said to be accurate to within -/+2%. By simply mounting to your handlebars and connecting to a Bluetooth or ANT+ speed sensor and computer, the PowerPod sets up super quickly. Bear in mind, you won’t get any pedaling analysis or other high-end cycling dynamics, but in terms of price, low-profile, and simplicity, this could be a good solution if you’re willing to think outside of the box.