THE BEST POWER METER
A power meter has become an essential component for cycling enthusiasts. When we think about how we can go faster, we now include getting the best power meter in the same conversation as getting a new bike or wheelset, which costs far more, or buying new tires, helmets, and kit, which don’t cost much less.
We use power meters to guide our training, measure our fitness, and, for some, assess our worth as cyclists.
So, it’s an important decision, at least if you care about getting faster. And, if you’re reading this, I’ll bet you do.
Choosing the best power meter has become a two-part decision. Do you get one as part of the groupset when you buy a new bike or purchase one separately? And, if you get your power meter after buying your bike or want to add it to a bike you already own, should it be part of your pedals, crank arms, or chainrings?
While I’ll explain the trade-offs to help you make those decisions, the good news is that power meters have become a mature market and technology. While there are still some noncompetitive outliers, prices have stabilized, performance has equalized, and options have normalized among the best power meters. The choice comes down to how much beyond US$330/£325/€400 you are willing to pay for installation convenience, pedal preference, model compatibility, power data geekery, and bike integration.
Based on those criteria, the best options for new bike builds are 4iiii crank arm power meters that are part of Shimano 105, Ultegra, Dura-Ace, and GRX groupsets or Quarq spider power meters that sit between the chainrings on SRAM Rival, Force, and Red groupsets.
If you decide to buy a power meter separately, the best choices for road and gravel cyclists are between crank arms with attached power meter sensors from 4iiii, pedals with integrated power meters from Favero, Garmin, Wahoo (road only), and Look (gravel only), and power meter spiders from SRAM’s Quarq division.
In this review, I’ll tell you more about how road and gravel bike power meter products are maturing starting just below, how to pick the best power meter for your needs and preference, and give you my reviews of the best power meters. (Click on those phrases to go directly to the part of the post that covers that topic.)
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POWER METERS HAVE MATURED
Over the last ten years, there’s been rapid growth in power meter use. Cyclists have seen the value power meters can bring to improving our performance. Technology has improved, applications have broadened, competition has increased, and prices have dropped.
While usage continues to grow, changes in technology, applications, competition, and prices have largely settled down and sorted out in the last few years.
Cycling enthusiasts have come to expect a power meter in the groupset of the most expensive new road and gravel bikes. Leading bike brands are putting them on their bikes selling for US$5,000 or more built with Tier 1 and 2 groupsets (Dura-Ace, Ultegra, Red, and Force) as standard equipment and offering them as an option on Tier 3 ones (105 and Rival). What was once a need served almost exclusively by after-market products is now filled almost half the time when we buy an enthusiast-level bike.
Copy-cat power meters from low-labor-wage countries have entered at the low end of the market. Some of the largest industry suppliers have acquired power meter companies (SRAM and Quarq, SRAM and Powertap, Shimano and Pioneer), established close supplier alliances (Specialized and 4iiii), and invested in or hired experienced power meter staff (Giant and Stages).
All of this indicates to me that, while still growing and certainly not old, the road and gravel bike power meter product market looks like a maturing young adult leaving behind a pretty wild time of adolescence.
Specifically, I see the following confirmation of this early-stage maturity.
Options have normalized: As in any maturing market, cycling enthusiasts have had enough time to focus on a shorter list of power meters and suppliers that best suit their budget, performance needs, and preferences. Those that don’t have broad appeal have either been marginalized or exited through acquisition or by closing down.
For example, Powertap and its gold-standard rear hub technology power meters were acquired and then shuttered by SRAM. Stages, which grew rapidly after creating the modern power meter market for amateur cyclists with its low-priced, crank-based power meter sensors, laid off its entire staff after falling victim to the economic downturn that affected fitness centers they supplied with stationary bikes during Covid and the entire cycling industry after the pandemic.
Direct force, strain gauge-based power meters are now only made for pedal, crank arm, and chainring spider locations. As I listed above, there are just a few top-performing power meter brands you should consider at each location, yet another indicator of the market’s growing maturity.
Performance has equalized: Power meters are often marketed around their accuracy. Claims run between +/- 1.0% and +/- 2.0%. If you are a road or gravel cycling enthusiast producing 300 watts, that 1.0% difference between the most and least accurate power meters is just +/- 3 watts. That amount doesn’t matter to anything other than your bragging rights and is easily overwhelmed by a dozen other things that could affect how much power you can translate to the road, from your wheel’s stiffness to your drivetrain’s cleanliness to you getting a better night’s sleep.
Power meter consistency, or getting the same reading day after day for the same power output, is more important than the absolute accuracy of your power meter readings. However, I’ve not seen power meter suppliers make claims about their product’s consistency.
Fortunately, there have been a lot of evaluations of the actual performance of power meters done by independent testers and publications I trust. The differences they show in the accuracy, consistency, drop-outs, top-end power, temperature compensation, communication to your head unit, and other measures of the best power meter models from the leading companies are nearly non-existent or so small that they shouldn’t matter to almost all road cycling enthusiasts.
I realize I’m taking a risk in speaking for all of my fellow roadies with that last italicized statement. Note that I’m not talking about pro or Cat 1 road racers or time trialists, triathletes, track cyclists, or their personal coaches. But frankly, I think there are probably many things that are more important to their training and performance, even for them, than these small differences between the best power meters.
There are differences in battery life, another performance measure, and how you recharge or replace your battery, which is more of a feature than a measure. There are also some differences in other features. But the biggest differences remain, as I’ve said before in the price you’ll pay for installation convenience, pedal preference, model compatibility, power data geekery, and bike integration.
Acceptance has been realized: Once thought to only benefit high-level racers, cycling power meters are now accepted as standard equipment by those who want to train better, ride faster, manage their efforts more efficiently, and do inside rides on Zwift. That means serious amateur cyclists like you and me.
The best power meters have moved well beyond being an analytical aid for personal coaches. As more roadies use training tools and programs like Zwift, TrainerRoad, FasCat, and those built into Garmin Edge computers and track their progress on Training Peaks (see my training plan review), a power meter has become an essential tool to measure your progress and guide your daily and long-term training.
AI is further enabling better coach-like tools for cycling enthusiasts. Power meter data, along with the heart rate variability and sleep tracking information from wearables, is central to their ability to give good advice.
If you do two or three 6-week training blocks well, with the help of a power meter, you could increase your FTP (functional threshold power) by 5-10% or more. This means you ride faster or save energy at the same speed.
When you know what power you can hold for 1, 5, and 20 minutes, you can also use your energy more efficiently on rides and in events. A power meter will tell your bike computer how much energy you burn overall and at key parts of a ride. Once you know this, you’ll know how many and how hot to burn those metaphorical matches you have during the most challenging sections of a ride.
A power meter set up on the bike you use for inside rides or built into your smart trainer has also become the tool you need to calculate your power-to-weight ratio. More so than speed or heart rate, your power-to-weight ratio in watts/kg is key to picking out the right Zwift group rides and measuring and managing your efforts during any ride in Watopia and other virtual worlds.
If you are new to training with power, here are two classic books I’ve read, continue to refer to, and highly recommend. Hunter Allen and co-author Andy Coggan wrote Training and Racing with a Power Meter which laid the foundation for much of what everyone is doing now with power. Joe Friel wrote The Cyclist’s Training Bible, the original and still the best resource I’ve ever read on endurance training. Friel’s later book, Fast After 50, is for those of us who want to keep improving despite our age.
Unnecessary features have been neutralized: There’s been an argument from some reviewers and suppliers that determining your power by independently measuring and adding how many watts come from your left and right legs is better than measuring your total power or doubling the power that one leg produces.
Unless you are coming off an injury, most riders will have a power imbalance between their left and right legs of up to 10%. Few of us will produce 50% of our total power from each leg, and a 2% variance (48/52 or 52/48) is very common. That seems perfectly normal since our legs are usually not exactly the same length and few of us are “ambipedal” or use our right and left feet and legs equally.
While I’m not privy to what some private coaches may be telling their high-level athletes, I’m unaware of any training prescriptions for riders with power imbalances in the 10% range. I’ve not heard or read of training guides, fitters, or power meter suppliers suggesting you do something different in your bike or strength training, bike or shoe fitting, or anything else to increase your power output if you have a slight L/R leg power imbalance.
No doubt, it’s interesting to know that you might have a 2%, 3%, or even 5% imbalance. But, recognize that you’ll pay nearly twice what you would in the initial purchase price for a pedal or crank arm power meter to have this information that you physically won’t do anything with and may obsess about.
While not comprehensive, my discussions with stores selling road bike power meters show a clear preference for pedal and crank arm power meters with a single sensor that measures and doubles the power you produce from your left leg, and saves you money.
I also haven’t seen proprietary pedaling dynamics and other analytical features built into Garmin and other bike power meter software incorporated into training plans and pedaling techniques I’m aware of, except perhaps for those used by the geekiest enthusiasts.
Pioneer’s crank arm power meters were differentiated around some very cool-looking pedal stroke graphic data and other analytical features. After struggling to get traction in the market with this approach, Pioneer closed its power meter business and sold its IP to Shimano, which has not appeared to have used it or put out an accurate or repeatable line of power meters with or without the aid of Pioneer’s technology.
As best I can tell, none of the leading power meter suppliers depend on proprietary analytical features to separate themselves from the others.
We will likely see more integration between power meters and other parts of the cycling electronics ecosystem. The latest 4iiii power meters have a Find My feature that acts as an air tag within the Apple ecosystem. Quarq is owned by SRAM, which makes electronic groupsets and Hammerhead bike computers. In addition to power meters, Garmin makes Varia radar and smartwatches and has the Garmin Connect app, a platform for creating some information or training benefits from using these devices together.
The possibility of integrating power meters with electronic groupsets, radar, GPS computers, personal fitness trackers, and other parts of the cycling and training ecosystem seems a more likely direction for future power meter development than making them another 0.x% more accurate or adding more device-specific analytics or features.
Prices have stabilized: As you might expect from any maturing business, power meter prices have stabilized. Only a handful of large-volume power meter suppliers remain, and with a few notable exceptions (Favero in the pedal power meter segment), prices for competing models used at the same location are very close.
With demand continuing to grow and after all of this sorting out and consolidation, I think it’s unlikely we’ll see more price declines until the percentage of cyclists using power meters gets closer to a peak.
HOW TO PICK THE BEST POWER METER
If you’ve been waiting for lower prices or fewer choices or to better understand how a road or gravel bike power meter can improve your speed and performance, you probably haven’t been alone. But, with the market maturing in the ways I described above, picking the best power meter for you and your needs has become much easier.
With little to no difference in how well the best power meters perform, choosing between them comes down to how much extra you are willing to pay for attributes that may be more or less important to you.
Those are:
* Installation convenience – If you ride one bike, a left-side crank arm power meter is the least expensive option. Alternatively, power meter pedals are the easiest kind to move between bikes if you have and want to measure power on more than one road bike.
Want to move your power meter between your road and gravel bikes? A crank arm power meter is your least expensive option. Unless you never plan to put your foot down in the dirt or gravel off-road, you don’t want to use road bike pedals. Even if you have a Shimano GRX gravel crankset on your gravel bike, it uses the same left crank arm attachment fittings as on Shimano road groupsets.
* Pedal preference – If you use Shimano or Look pedals, then Favero’s Assioma or Garmin’s Rally power meter pedals will suit you and be the most convenient power meter for switching between road bikes. Wahoo’s POWRLINK pedals meet the needs of those who want power meters built into their Speedplays.
Note that Favero’s Assioma for Shimano pedals has a longer spindle than the standard one, and Wahoo’s POWRLINK has only one spindle length vs. the several they offer on their standard pedals. If your fit is very sensitive to a few mm of Q-factor difference, these solutions may not work for you. More on this below.
Gravel and mountain bikes use different pedals than road bikes. Garmin’s Rally power meters allow you to change pedal bodies to switch between road and off-road use. And Favero and Look make good dedicated SPD-compatible off-road power meter pedals.
All of these power meter pedals come at a price premium to a single-sided crank arm power meter.
If you prefer Time or another road or gravel pedal model, a left-side crank arm power meter is the lowest-priced option and the easiest to move between bikes. Dual-sided crankarm and spider power meters are more expensive and require more work to switch from one bike to another.
* Model compatibility – Power meter pedals work with any crankset. There are zero compatibility issues with power meter pedals.
Most enthusiast-level road and gravel bikes have Shimano or SRAM cranksets. 4iiii sells Shimano crank arms or cranksets with power meter sensors installed. (Shimano also makes power meters for their cranks, but they are inaccurate and should be avoided.)
If you have SRAM, Campagnolo, Cannondale, or many other cranksets as well as a Shimano, you can send the left crank arm or the complete crankset to 4iiii, and they will install their power meter sensors on them through their factory install program. While you’ll have to be without your gear for 2-3 weeks (do it during your offseason break), this can keep your cost down and give you the option to get a power meter on crank arms that you wouldn’t otherwise be able to.
Spider power meters also require a model compatible with your crankset. Between those sold by Quarq, Power2Max, Sigeyi, and Magene, you can usually find several options that fit just about any crankset.
You install the spider power meter between your chainrings or replace one of the rings with the power meter and keep your existing crank arms. However, for some cranksets, notably Shimano ones, you have to replace the crankarms as well, making for a more expensive and less well-integrated proposition.
* Power data geekery – If you want to totally nerd out on power data, you’ll probably want left and right-leg independent measurement capability only possible from power meters with sensors in both pedals or crank arms.
Spider power meters give you total power and have an algorithm to estimate L/R metrics based on how you torque the spider during your pedal stroke. While I’ve found the calculated balance is within 1-2% of what you’ll get from independent measurements over the course of a ride, it’s not a true L/R measurement for those of you who insist on it.
There are various pedal balance, efficiency, and “smoothness” analytics over different time intervals you can measure if you have L/R power measurement.
Favero Assioma pedal power meters also provide Garmin’s Cycling Dynamics suite of metrics, which is captured exclusively on Garmin head units. They can show you things like how much time you spend standing vs. seated, how much power you are putting out in each part of your power stroke, and where your power is distributed across your pedal.
It’s all very interesting data that may excite the geek within us. However, we cannot do much with this data other than perhaps become obsessed with it. It also costs more to feed it.
And yes, I bought independent left/right power meter cranks after breaking my femur on a ride. But, after healing and rehab, and a few years of looking at my 2-3% imbalance, I’ve found worrying about it is a major distraction to my training focus and the pleasure of riding my bike. I do nothing differently with that knowledge and nothing in the Cycling Dynamics suite that would influence my training.
Frankly, I don’t even look at it after rides anymore, let alone during them.
I will note that some friends who have a power meter know their FTP and watt/kg data better than their spouse’s telephone number after they’ve put it on speed dial, but they don’t train to any kind of plan that uses these power numbers. This renders their power meter an expensive toy that can only mess with their ego as it bounces up and down. Don’t be that guy or girl.
*Bike Integration – The best power meters will functionally work with any road or gravel bike whose groupset they’re compatible with. However, some power meters will look more integrated than others.
Single-side crank arm power meter sensors are mostly hidden on the back of the left-side crank arm.
Dual-sided 4iiii crankset power meters show the drive-side power meter sensor facing out between the chainrings. They look integrated but are not as clean as a crankset without one.
Favero and Wahoo road pedal power meters have power meter sensor pods wrapping around the spindle area between the pedal and cranks. Some are turned off by how they look. Garmin road and gravel power meter pedals and Favero and Look gravel power pedals hide the sensors inside the spindle and look like regular pedals.
Spider power meters run the gamut of integration. Quarq spiders inside parent company SRAM groupsets look like they were made for each other because, well, the latest ones literally are. Other combinations look like they are made by different brands. Some lean into this by offering a range of colors or displaying bold logos. A spider power meter inside a Shimano crankset requires you use different cranks and looks, to me at least, like an ugly mutt.
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REVIEWS OF THE BEST POWER METERS
As I wrote in the opening of this post and detailed in the sections above, there are no meaningful performance differences between the best power meters I’ve listed below for most road and gravel cycling enthusiasts.
Instead, you should choose among them based on how much beyond US$330/£325/€400 you are willing to pay for installation convenience, pedal preference, model compatibility, power data geekery, and bike integration.
Below, I’ll review the best crank arm, pedal, and spider power meters for road and gravel bikes against those criteria.
CRANK ARM POWER METERS
For as little as US$330/£325/€400, a left-side 4iiii crank arm power meter is the lowest-priced direct-force option available to consistently measure your power and get all the performance data and training benefits most cycling enthusiasts need.
As I wrote earlier, Stages Cycling brought modern power meters to the cycling enthusiast masses with the first crank arm power meters that sold for under US$1000. They reduced their prices in steps as volume grew and product developments made it possible. Increased competition from 4iiii and power meters made for other locations on the bike also forced prices down. With the downturn in the cycling industry after COVID-19 and the closure of health clubs that used indoor bikes made by Stages’ larger business division during the pandemic, the company struggled financially for several years and in the Spring of 2024, laid off their staff and stopped making power meters.
4iiii was Stages’ largest competitor. It has been making power meters for nearly as long and competed successfully with them on price, technology, and performance.
I’ve tested their latest model 4iiii Precision 3+ left-side and Precision 3+ Pro dual-sided power meters on Shimano Ultegra cranks. I’ve also ridden earlier models of their left-side power meter crank arms. Independent testers have verified their accuracy is on par with other leading power meters in a wide variety of riding situations.
More simply put, they just work. The newest Precision 3+ models also stay charged for an entire year or more of riding and help you find your bike using your Apple iPhone if you ever get separated.
Yes, the latest 4iiii power meters claim an 800-hour battery life for the single-sided power meter and 550 hours for the dual-sided one before you have to replace the standard CR2032 coin cell lithium-ion batteries they use.
While I haven’t tested mine that long, if true, that’s the equivalent of a year or more of riding for the 8-12 hour/week cycling enthusiast. Pedal power meter batteries need to be recharged or replaced roughly 10 times as often.
You can get new Shimano crank arms or cranksets equipped with 4iiiii power meters already installed for 11- or 12-speed road groupsets and GRX and XTR off-road ones. You can also get 4iiii power meters added to your Shimano crank arms and cranksets and on many SRAM, Cannondale, and FSA left-side crank arms by sending them to their factory.
The US$330 factory-installed power meter price applies to any single crank arm you send to 4iiii. It’s US$530 to get the dual-sided power meter installed on your Shimano crankset.
Buying a new 4iiii equipped 12-speed Shimano left-side crank arm will cost you US$330 for a 105, US$480 for an Ultegra, US$515 for a Dura-Ace, and US$370 for a GRX.
Dual-sided 4iiii Shimano cranksets will run you US$950 for the Ultegra or US$790 if you just buy new left and right crankarms with the 4iiiii power meters pre-installed to put on the rest of your crankset. A new 4iiii Precision 3+ PRO GRX crankset for your gravel bike costs about $770. It gets pricey at the Dura-Ace level, costing US$1225 for a new power meter-equipped crankset.
Use the links to recommended stores BTD, Merlin, Sigma Sports, and Amazon to order one of these options.
If you’re buying a new US$5000 or more expensive bike, including a Specialized Tarmac or Aethos bike and selected models from Canyon, BMC, Orbea, or others with a Shimano Dura-Ace, Ultegra, or even a 105 or GRX groupset, there’s a good chance it will be pre-built with a 4iiii power meter, or you can spec one into your build.
While it’s hard to put a price on how much more you’re paying for the power meter, a couple of retailers I talked to told me it costs about 20-30% less to get the power meter as part of the bike purchase than if you were to get it afterward.
Further, most enthusiasts buying a bike with a Tier 1 or Tier 2 equipped groupset expect a power meter. Having a dealer remove it will not save you a whole lot if anything. And it’s often not an option to have it removed on a complete, pre-built bike at an online retailer or from an LBS.
If you see a Shimano power meter, either on a new bike or available for purchase separately, I’d encourage you to avoid it. In addition to being far more expensive than a 4iiii power meter, it is inaccurate.
That said, let me discuss the pros and cons of having a crank arm or crankset power meter.
Installation and Transfer: While not as easy to install and transfer as a pedal power meter, crank arm power meters are easier to set up and transfer than a spider power meter.
Here’s a video on how to replace a left-side crank arm and an entire crankset. As an enthusiast with no wrenching experience and indeed never having changed a pedal, crank arm, or crankset myself before getting my first power meters, I can assure you this is all quite doable in short order.
It is also wise, and I’d highly recommend using a small torque wrench when fastening your left crank arm. This ensures you don’t over- or under-tighten your crank and, equally important, that it doesn’t move around on you. After installing or transferring, you should run a zero offset.
Most crank arms tighten with less than 15NM (clearly noted on the crank arm), requiring a much smaller, very portable, and inexpensive wrench.
Pedal Preference and Model Compatibility: Crank arm power meters don’t limit your choice of pedals the way pedal power meters can.
However, power meters aren’t available for all crankset brands and models. If there isn’t one for yours, you may need to opt for a pedal or spider power meter.
Power Data Geekery: With power sensors on both your left and right crank arms, you can get independent power measurement, pedal balance, efficiency, and “smoothness” analytics. But, if you want to fully geek out on the Cycling Dynamics metrics, you’ll need a Garmin or Favero pedal power meter.
As I wrote earlier, a left-side crank arm power meter provides all the valuable power data most enthusiasts need. It also makes transferring between bikes quicker and simpler than a dual-sided one.
Bike Integration: Crank arm power meters are practically invisible and normally added to the groupset without changing the look or spec of the bike.
PEDAL POWER METERS
Road power meter pedals: Favero Assioma Duo (left), Garmin Rally RS200, Wahoo POWRLINK
A power meter built into a road or gravel bike pedal is the easiest to install and transfer between bikes. It is also compatible with any crankset a cyclist might own. This makes pedal power meters among the most attractive options. This is especially the case if you have more than one bike or different model cranksets on the bikes where you want to measure power.
With the expiration of Shimano’s patent for SPD-SL and SPD pedal bodies and the increased demand for power meters, options for roadies with pedal preferences for Shimano, Look, and Speedplay (financially rejuvenated after being acquired by Wahoo) all now have power meter pedal options.
The power meter pedal options aren’t as comprehensive as the pedal lines they’re based on, but for a price premium compared to most crankarm and spider solutions, you can find a pedal power meter that is spot on or comes close to the feel of the unelectrified pedals you’re used to riding.
Since it came on the scene in the twenty-teens, Favero has been the price and performance leader. While Garmin and Wahoo pedal performance measures now match Favero’s, the price for the Assioma UNO (US$495/£475/€515) and DUO (US$760/£720/€830) with Look KEO-style pedal body power meters remains significantly less than the price for Garmin Rally single-side (US$600/£530/€550) and dual-side (US$1100/£870/€989) and Wahoo Powrlink (Speedplay Zero) single (US$650/£550/€620) and dual (US$1000/£850/€1065) side power meter pedals.
Favero’s prices for single-sided UNO power meter pedals are in the same neighborhood as new, left-side crank arm power meters for Ultegra and Dura-Ace groupsets. The dual-sided Favero DUO pedals are less expensive than buying new power meter cranksets for those two groupsets, though a premium over having 4iiii turn your own crankset into a power-meter one.
And if you are a Shimano SPD-SL user, as most roadies are, or use Speedplay pedals which many are loyal to, you may find Look KEO-style pedals have inferior performance, fit, and durability characteristics, which I have also found to be the case in my testing.
The sensor pods on Favero and Wahoo power meter pedals are hard to miss for those who value bike integration highly. Garmin’s gravel and MTB version of its Rally power meter pedal is also a chunky monkey but the Favero and Look off-road power pedals are hard to distinguish from regular ones.
Gravel/MTB pedals: Look X-track, Garmin Rally XC, Favero Assioma Pro MX
Off-road power meter pedal prices track road ones with the Favero (US$500/£450/€620 for the MX-1 single-sided and US$810/£720/€925 for MX-2 dual-sided) costing far less than the Garmin (US$700/£570/€590 XC 100 and US$1200/£960/€1105 Rally XC200) and Look X-Track (US$760 and US$1100).
For those who haven’t bought a bike with power meters included as part of the build, retailers have told me that those who want a power meter will more often than not buy a pedal power meter. Their ease of installation and transfer between bikes is the biggest thing going for them, and the potential to geek out on pedal dynamics, left/right power, and other types of power measurement tomfoolery built into the dual-sided version adds a lot of sizzle for many enthusiasts.
In the sections below, I’ll describe and highlight each of the best pedal power meter features.
Favero
Favero makes their Assioma line of power meter pedals for road and off-road use. Their Assioma Duo and Uno road pedals are dual- and single-sided power meters, respectively, that use Look KEO-style road pedal bodies.
The Assioma Duo-Shi (US$660/£575/€740) are dual-sided power meter pedal spindles you replace in your Ultegra or lower-tier Shimano road pedal bodies.
The Assioma Pro MX-2 and MX-1 are dual and single-side SPD power meter pedals for gravel or MTB riding.
All of these perform flawlessly and, as I detailed immediately above, are significantly less expensive than power meter pedals sold by other brands.
The single-sided models are also very price competitive with new 4iiii Shimano Ultegra and Dura-Ace left crank arms, while the dual-sided Faveros are much less expensive than new, dual-sided 4iiii Shimano Ultegra and Durace cranksets.
There are no better options if you prefer or are compatible with the road and off-road style pedals they support and you want a power meter in your pedals to move between bikes.
Well, at least for most of us.
Those who are long-time users of Shimano pedals or can’t accept the inferior performance of Look KEO pedals will likely not love Favero Assioma’s Look KEO-style pedal bodies. While I found the Favero-supplied Look KEO pedal bodies (not made by Look) actually perform better than the pure Look KEO pedals made by Look, they still fall short of the stability, durability, maintenance, and quiet operation of the Shimano Ultegra pedals.
The Favero Assioma DUO-SHI, which are power pod-equipped spindles that you put into original Ultegra or lower-tier Shimano pedal bodies, have a longer spindle width or Q-Factor to make room for the power pods. Some find the 5-10mm effective extra width objectionable to their fit.
This difference was much discussed and, I think, incorrectly judged for the DUO-SHI when it first came out. Fitters I’ve talked to estimate that over half the riders they’ve worked on, especially those who are tall, have large feet, or have tight hip flexors from sitting in an office chair day after day, need spindles longer than the common 53-55mm Q-factor of other power meter pedals.
Placing Shimano (or Look) cleats more inside or outside on your shoes can give you up to 5mm more or less width than setting them right in the middle. So the effective ranges are more like 50mm to 60mm for most and 60mm to 70mm for the DUO-SHI. So instead of a 53mm or 55mm Q-Factor you may get from standard Shimano pedals and cleats, you may need and can get an effective 60mm Q-Factor set up from the DUO-SHI
This short video segment from a Peak Torque review of the DUO-SHI explains this in more depth.
Oh, and if you also ride a gravel bike or mountain bike, know that cranksets used on those bikes already push your feet out much more than the 10mm or so difference you’ll get with the cleats placed in the middle of the road shoes you use with these power meter pedals.
For those who aren’t comfortable with the extra spindle width of the DUO-SHI or the performance of Look KEO-style pedal bodies on the Assioma UNO or DUO, your options are the Garmin Rally RS100 for about US$150 more than the UNO or RS200 for US$350 more than the DUO and US$450 more than the DUO SHI.
If you want new or need replacement Shimano pedals for the Assioma DUO-SHI, the additional US$200 or so cost for the pedals only reduces the gap between the cost of the Favero and Garmin Shimano power meter pedal solution by about half.
The Garmin Rally pedal batteries last 2x to 3x longer than the Favero Assioma. However, the Rally uses disposable and less common button cell batteries, while the Favero’s rechargeable ones last for about 50 hours or a month of riding in my tests. I simply recharge my Assioma batteries at the beginning of each month at the same time I recharge my electronic group set. I live by a simple first-of-the-month mantra: pay the bills and charge the batteries.
You can order Favero pedals and support this site when you use these links to BTD, Performance Bike, and Sigma Sports. I’ve vetted all of these stores and recommend them for their competitive pricing, independent customer satisfaction ratings, range of enthusiast-level road and gravel cycling gear and kit, and support of my ability to keep reviews like this one coming to you from the small commissions the stores pay without adding any cost to you.
Wahoo
With the introduction of Wahoo’s Powrlink Zero in 2022, Speedplay pedal loyalists finally have a power meter to call their own. Like Favero’s design, the Powrlink’s sensors sit in pods on the spindle between the crank arm and pedal itself.
At US$1000/£850/€1095 for the dual-sided Powrlink Zero and US$650/£550/€620 for the single-sided version, it’s priced similarly to the Garmin Rally power meters. Battery life is a more-than-ample 75 hours, and, like the Favero, they recharge using magnetic, clip-on power cables. The Powrlink gives you the power and cadence data you need but doesn’t calculate the suite of pedal-specific metrics that Garmin and Favero do and that no one knows what to do with.
Trusted independent testers have shown the Powrlink performs well – accurately and consistently – similar to what I found on my test rides in a less geeky and more feels-right, looks-the-same comparison with a crankset power meter I rode at the same time. Wahoo has proven its power measurement experience from its smart trainers and has significantly retooled the Speedplay line and manufacturing facilities since acquiring the business.
With Favero and Garmin offering both Shimano and Look power meter pedal body options and Wahoo offering a Speedplay one, most roadies can now find a competitive power meter pedal solution to suit their preferred pedal platform.
I became a long-time Speedplay devotee after my fitter first introduced me to their wider range of float and spindle width options. My hips and knees thanked me for switching to these pedals, especially for the 65mm spindle width I needed but couldn’t get on Shimano pedals.
While Wahoo continues to offer different spindle widths for Speedplay Zero pedals, I was super bummed when the Powrlink came out in only a single 55mm width. While the float range is still there (built into the cleats), it’s a shame that those like me who came to Speedplay to get a better fit can’t enjoy the Powrlink.
But other things that have made Speedplay special – float range, ability to clip in on either side of the pedal, and good stability once clipped in – are still there in the Powrlink. In addition, Wahoo has eliminated the high maintenance required in the previous design of Speedplay pedals, and their new manufacturing facility produces higher-quality pedals than the previous one.
If you don’t have a pedal design preference and are attracted to the ease of installation and universal compatibility that pedal-based road bike power meters offer, I recommend the Favero Assioma UNO (Look) or DUO-Shi (Shimano) over the Powrlink for the Favero’s superior price and proven long-term reliability.
You can find and order the Wahoo Powrlink using these links to BTD and Sigma Sports.
Garmin
The Garmin Rally RS and XC were the first available power meters to use Shimano SPD-SL road and SPD off-road pedal body designs, respectively. The Rally line also includes the RK, which uses a Look KEO-style pedal body and on which the original Garmin Vector, now Rally, is based.
All of the Rally models are available in single-sided and dual-sided versions. They use the same spindle system with the electronics built into it rather than having a separate pod housing the electronics as with the Favero and Wahoo power meter pedals.
You can buy the power meter with one of the road pedal bodies and buy the off-road one separately, or vice versa, and then switch between them. It adds quite a bit of expense to what’s already one of the most expensive power meter solutions.
Switching between them also isn’t a quick or simple job. It will take you 20-30 minutes, a handful of tools, and a bit of concentration. It’s something you might want to do a few times a year rather than every month or week. But you can do it.
If you prefer Shimano pedals and can’t live with the added spindle width of the Favero Assioma DUO-SHI, the Garmin Rally RS100 single-sided, and RS200 dual-sided power meter is the way to go.
Other than that, unless you see great benefits from Garmin’s suite of power analytical tools or being part of the Garmin ecosystem – and if you do, please let me know what they are – I can’t see any reason to pay more for these pedals than what Favero offers for road pedals, what Favero and Look offer for off-road ones, or by going with a crank arm or spider solution.
In addition to the added price, the Rally RS pedals are 40 grams heavier than standard Ultegra pedals and have a 2mm greater stack height than the Ultegra pedals you’d use on the Favero Assioma DUO-SHI. They also come in only one available spindle length – 53mm – though you can adjust the cleat placement to get +/-5mm more effective Q-Factor width.
If the Garmin Rally RS is your key to Shimano power pedal happiness, you can order it or any of the Rally products at BTD, Performance Bike, Sigma Sports, and Amazon.
SPIDER POWER METERS
Power2Max (left) and Quarq power meters
Spider power meters that bolt onto your chainrings are one of the original power meter designs. Because of their longevity, spiders are often viewed as a power meter benchmark. They have been improved to provide some high accuracy rates for a wide range of crankset models.
Road, time trial, triathlon, and track racers, along with traditional roadies of all stripes, often favor spiders for their proven record over many years of experience.
Power2Max and Quarq power meters serve the broadest range of road cycling enthusiasts and crankset models with competitively priced products. They are both highly reliable. While I haven’t, independent reviewers who have tested Sigeyi and Magene spider meters rate their accuracy at the same level as P2M and Quarq
The original power meter manufacturer SRM makes significantly higher-priced spider power meters but their performance no longer measures up.
A spider can be the best, most cost-competitive solution for your current drive train situation and how you intend to use a power meter.
You’re a good candidate for a spider if you plan to focus your power meter measurement principally on one bike, already have a crankset model that only requires you to add the spider to get you going with power, and don’t much care about pedal stroke analytics or independent leg power measurement (they measure total power and use an algorithm to project each leg’s contribution), and want to use your preferred bike pedals models.
If some of those situations don’t describe you, a pedal or crank arm power meter will likely be a less costly and more suitable way to go. Here’s why.
Installation and transfer: Similar to changing your chainrings, a spider takes more work to install than other types of power meters. If you’ll be using it mostly on one bike, not a problem. Install it yourself if you are handy and have the tools. Have a friend or shop install it if you’re not.
To move your power meter spider between bikes, you’ll need to move the entire crankset, similar to the way you would one with power meter sensors on both crank arms. It’s certainly doable, but it will take 15-20 minutes out of your riding time to make the switch and clean up once you get good at it. This compares to 5-10 minutes to switch your pedals or left crank arm. The video in the section above on crank arms shows you how.
You’ll also need the same bottom bracket on any bike you want to use with the same power-meter-equipped crankset.
Price: Since a spider power meter connects to the drive-side (right) crank arm to the chainrings, it is made for specific crankset brands and, sometimes, models. Depending on your crankset, for example, a SRAM model, you’ll only need to buy the spider. That’s the least expensive solution and can cost as little as US$330 or no more than a left-side factory-installed 4iiii crank arm power meter or new 105 model one.
Model Compatibility: To put a spider power meter into your Shimano crankset, you’ll need to change your crank arms. With some cranksets, you’ll also need a different bottom bracket and/or chainrings. That can boost the price to between US$600 and $800 or more and leave you with an entirely new crankset that doesn’t perform as well or look as integrated with your groupset as the ones you replaced.
Instead, spider power meters are typically more cost-effective if you have a SRAM crankset or one made by Specialized Cannondale, Rotor, FSA, Easton, or Praxis.
Power2Max makes spider-only power meters for the widest range of cranksets including those who already own many Rotor, SRAM, Cannondale, or Specialized cranksets and won’t need to change their crank arms. These sell for US$490/€490 and up for their NGeco models that claim +/-2% accuracy and use a coin cell battery that should last you an entire year before needing to be replaced (400 hours). You don’t get estimated left/right power balance or pedal smoothness with the NGeco spiders but for $50/€50 each, you can buy a software upgrade that will give you that data.
For twice the price, US$940/€990 or more depending on the model, you can get a Power2Max NG that claims +/-1% accuracy, gives you faux left/right balance, pedal smoothness, and torque efficiency data, and a rechargeable battery that lasts for about 3 months (150 hours) between charges.
Both Power2Max spider power meter lines can also be delivered with new crank arms for FSA, Rotor, Easton, and Campagnolo cranksets.
Quarq, owned by SRAM, has a more SRAM-centric product line. They make spiders for the full range of SRAM’s newest electronic Red, Force, and Rival AXS groupsets and some of their older mechanical Red and Force cranksets.
You’ll likely find Quarq power meters integrated into new bike builds with Red and Force groupsets and increasingly, Rival ones as well. SRAM and Quarq seem to be ahead of Shimano and 4iiii in getting many leading bike companies to put power meters on bikes selling for over US$5000.
Quarq takes a more agnostic approach than Power2Max to serve cyclists who are looking for a power meter after they buy a bike.
Rather than try to fit their spider to your cranks, Quarq sells you the spider along with their Quarq or SRAM cranks. While their spiders alone are competitively priced as low as US$450, you’ll need to add roughly US$250 to $600 for Red, Force, or Eagle crank arms if you don’t already own a SRAM crankset. You’ll also need a DUB or EXP bottom bracket (US$40) to go with those cranks.
Quarq’s DZero (5-bolt) or DFour (4-bolt) spider power meters fit the chainrings used in most of the leading cranksets you may own. You can also add rings to go with these spiders for another US$180.
It’s a modular approach that starts competitively but gets more expensive if you don’t own a SRAM crankset. But Quarq’s long track record of performance and reliability and its large footprint at SRAM dealers make it a solid option if a spider power meter is a good solution for your situation.
Pedal Preference: If you have a strong pedal preference, the spider power meter doesn’t limit your choice.
Measurement and Analytics: A spider power meter measures your total power rather than adding your left and right power (dual pedals and crank arms) or doubling your single-leg power (left-side pedals and crank arms).
After all, there’s only one spider, and it’s bolted to the chainrings and torqued at a given cadence by both crankarms and pedals to produce a power reading.
Instead, Quarq and P2M road bike power meters use algorithms to estimate your left and right leg power balance. They promote “dual-sided power metering” and “separate left-right power balance” even though they don’t measure it directly from power meter sensors on the left and right sides.
Some reviewers say these spiders mirror true independent leg-measuring power meters in side-by-side tests, while others say they don’t. My experience riding simultaneously with the spider, dual-side crank arm, and pedal power meters shows a 1-2% difference in the estimated and measured left/right power balance values after 1-2 hr long rides on various terrains.
This is one of those po-ta-to vs. po-tah-to differences that shouldn’t result in, as the lyric goes, deciding to call the whole thing off. For me, the reasons I’ve described above are more important ones when deciding whether or not to buy a spider power meter, unless your inner geek tells you otherwise.
You can order Quarq rear using these links to BTD, Performance Bike, Merlin, Sigma Sports, and Amazon.
* * * * *
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Thanks, and enjoy your rides safely! Cheers, Steve.
This is a really great summary!
In my experience, any leg imbalance is quite consistent for a person. Since single sided power meters actually double the watt of your one leg, to estimate the power of two legs, a 3% L/R imbalance at 300W starts out being 9w but is then doubled to 18w, which could be a problem. That’s why 4iiii have a great advantage compared to Stages, because 4iiii allows you to adjust the ‘scale factor’. So if you have the possibility to compare your single side crank arm power reading to a smart trainer (consider drivetrain loss), you may calculate the imbalance, adjust the scale factor (in this case 0.94) and have the 4iiii report corrected numbers!
Henri, Thanks for your kind feedback and for adding the tip on the 4iiii scale factor.
To follow up on your example, even if you don’t adjust your power meter for the imbalance, is there anything you would do differently with a reading of 282 vs. 300 watts or a 3% known imbalance as long as those readings are consistent? While you might feel better about yourself with an 18 watt higher reading (even though you are producing the exact same power), what if I or a mate told you that your power meter consistently reads 2% higher than others? At least for now, and after 5+ years of having independent L/R measurement capability, I’ve not read or heard about different training approaches because of small imbalance or even the suggestion from credentialed coaches that you should strive for a balance. And as long as your power meter reads consistently and your L/R balance is consistent, you should do the same training and get the same benefits of training with any of the power meters I’ve reviewed above.
Good news for us roadies, there are many other things that have a real effect on our power output and speed that we can worry about! 🙂 Training program, aero position, shaved legs, chain friction, etc. Any of those will keep us busy for a long time. Cheers, Steve
Hi Steve
You’re right, power number precision (repeatability) is relevant and accuracy is not so much.
Only exception is when mixing different devices. In in my case, mixing indoor workouts (smart trainer measured power) and outdoor workouts (power meter).
Henri,
Great comment regarding 4iiii’s scale factor. I was a former Stages left-side only user and it always seemed that my power output was too low compared with my performance. I switched to Assioma dual-sided pedals 2 years ago and of course they proved that my left leg was the weaker one, thus under-reporting my power.
But here’s where it gets interesting. You state that leg imbalance is quite consistent for a person. In my case, I have found the the disparity between legs increases with effort. Typically for moderate efforts I am L/R 46/54. If it stayed that way across all efforts I could shrug it off. But for light efforts I am at 48/52, or even 50/50 if I focus on my form. But at the other extreme, I did 10 minute efforts at threshold earlier this year and my balance was a disturbing 41/59. My data over the course of the last few years proves this again and again: the harder I go, the greater the disparity. So I am wondering if anyone else with dual-sided power has experienced this, or whether it should be addressed. (Bike fit? More strengthening of the left leg?)
Steve, thanks so much for another extraordinarily researched and informative post! I really appreciate it.
Also to add 3 more advantages of dual-side power meters:
1. Can do single-leg drills on the trainer. (Stages not only would not record, but would pause the workout. Pedaling right leg only was as if I had stopping pedaling)
2. More accurate for shorter efforts, since there is twice the data for a given time. Useful for sprinting.
3. If you are competing on Zwift, your power/weight ratio will be more accurate (if you have a significant leg disparity)
Andre, IQ2 is a current example of a power meter that, like many that never made it during the boom years, was announced, redesigned a year later (from a crank arm to a Look KEO pedal power meter), has missed shipping date goals, is not yet in production, has not had production units independently tested on the road for performance and reliability, but sounds terrific if it ever delivers as marketed and priced.
Check back in a year. They may or may not be able to deliver on what they are working on. Unfortunately, too few companies new to power meters have been able to do so. Steve
Ron, If it makes you feel better, Favero and Quarq have updated their firmware so that once set, you don’t need to zero offset unless you transfer the power meter. And, my personal experience as an old guy is that a power meter, training, and weight loss make up a virtuous triangle. Using a power meter made my training easier/better and caused me to lose weight.
And yes, I’d welcome your input on typos and edits. (send to:[email protected]). My eyes get a bit glassy after writing, reading, editing, over and over as I put these reviews together over weeks to the point where I can’t see it anymore. Thanks! Steve
Ron,
I built up a bike last summer and bought a Quarq Dfour spider power meter and it works great. Best feature, no calibration or zero-offset required before you ride. Problem solved!
-Kyle
Brilliantly clear article – quick question. My road bikes are all Ultegra and gravel bikes Shimano 105. If I were to buy an Ultegra model of either the Stages or 4iiii left crank power meters is there an issue switching between the Ultegra and 105 cranksets?
David, nope, none at all. I’ve transferred a left Shimano power crank arms among Ultegra, 105 and GRX cranksets. The Shimano crank fittings are all the same. Steve
Do all the options support using their own proprietary head unit or sending the data to a smart phone? I’m trying to figure out the best way to consolidate the visualization of data while riding.
Whitman, none use proprietary head units. Use standard cycling GPS head units that read ANT+ and BLE like one of these from Garmin or Wahoo. And while some recreational riders do, you really don’t want to put your smartphone on your bars (too big, not crashworthy, battery hog, not purpose-built, need apps, limited functionality, etc.). Steve
Maximilian, Thanks for your kind and constructive feedback.
Regarding coaches, I agree that power meters don’t render them unnecessary. It’s more like coaches aren’t absolutely necessary to do good training as they were before. Now, if you’ve got a training plan or subscription from one of the better services and Training Peaks to track your progress, you can use a power meter to follow the plan guided by all the metrics you mention. Yes, the plans are written by coaches but they don’t require you to have them on retainer and customize the program for you. Certainly better if you can afford it, but not necessary. I write about this in the Acceptance has been realized section further down. Reading the Hunter Allen and Andy Coggan book that I mention in that section will also tell you all about those metrics.
On customer service, I agree with you. I haven’t researched this rigorously and wish I could for all the products I review. Reading through comments on forums and at the end of other reviews and talking with a few retailers about their experience with some of these power meters didn’t pop up persistent reliability issues or an unusually high return rate beyond (beyond the Garmin pedals which I cautioned against) or customer service complaints. I know, not the best way to measure this but that’s about all that’s available unless I did a more rigorous study.
3-4 years ago, this was a bigger problem with the power meters. All six of the ones I’ve reviewed here have been around long enough to have resolved prior issues (e.g. Stages battery doors) they may have had with product iterations (except Garmin). If there were still reliability or service issues, I think we’d be hearing about it. Some that couldn’t resolve their issues have left the business for this very reason. Cheers, Steve
Thanks Steve. I have not only read Hunter’s book, but also attended one of his camps in the US and promoted two others :-). This one still is, as you mention, the go to book for anyone interested in learning more about power meter and all the metrics involved. My comment regarding the need for a coach is that, based on the athletes I have been around (i.e. have sold units to and/or trained with), those who elect to forego the coach end up looking at the numbers on the computer’s screen as if the readings alone would make them perform better. But you are right about the online coaching platforms. They help bridge the gap, so to speak. Cheers.
Hey Dennis, Yes, Stages makes one. See here or here though you may need to wait for your crank length to come in stock. Steve
Paul, Thanks for your comment. First, I have never reviewed and do not recommend Farsports gravel or road wheels.
As to the power meter, I am familiar with the GP Lama report that you site. This report broke some new ground in their testing approach and findings. Other independent reviewers using different protocols didn’t find similar issues with the Stages and 4iiii power meters they had tested. More recently (as in since I first published this review), Ray at DC Rainmaker reported a similar issue with the 4iiii model but has been less than definitive about the Stages right. Whatever is causing the issue, it seems to be confined to the right side only of the latest 8000 Ultegra and 9100 Dura Ace models. So I’ve now updated my review to recommend the left side only power meters for those who have Shimano cranksets. I’ve not seen anything about the 105 and GRX right side power meters but I’d err on the side of caution and recommend against their right side power meters as well. I’ve always recommended most enthusiasts only need a left side power meter anyway.
For your situation where you can’t fit a left-side power meter and use MTB SPD pedals, you’ve probably seen that Garmin has introduced the Rally XC100 and XC200 MTB SPD power meter pedals. They are pricey and I’ve just now gotten a pair to begin testing, but that’s an option. SRM makes one as well but it’s even more expensive and the jury is still out on their performance. Another option would be to go with the left side Favero Assioma Uno pedals and buy yourself a good pair of road shoes. You’d still come out ahead after buying the shoes. 🙂 Steve
Hi Steve,
Thank you for your fast reply!
I never intended to suggest you recommended Farsports wheels. Your articles about all the different aspects of a carbon wheelset really helped me make my own decision. I just wanted to share the outcome of that decision, just fyi.
Thx for the tip on the Garmin new pedals, I was not aware! Way out of budget though, I considered buying vector 3’s with the RC kit but no go either.
I am trying to get some quantification on how bad the ‘4iiii right only’ option would be for my training, am just an amateur enthousiast who rides apr. 200km/week and a few cyclos each year.
If the 4i option means my measurements will be within a 5-10% variation I think the influence on my actual training would be neglectable.
The video off the former 4i/Garmin PM engineer on the GP Lama site suggests the variations could run up and over 25% theoretically, that’s kinda scary but (hopefully) not very likely…
I’ll dive some more into it, thanks for your help!
Steve, long time reader and user of your reviews. Your testing and research convinced me to go tubeless on my BMC Roadmachine. I also followed your lead and upgraded to the ENVE 3.4 AR wheelset. I am now in the process of buying my first gravel bike and following your lead with a Giant Revolt. Although speced with GRX the crankset is a Praxis. My road bike has a Stages LH power meter (Ultegra crankset) which is very reliable. Stages does not offer a power meter for Praxis cranksets. Did you swap out your crankset for a GRX to accommodate a Stages? There are other options (pedals or spider based) but all have long backorders. Thanks for all you do. Joe
Joe,
Thanks for your confidence in my recommendations. Glad they’ve worked out. Feel free to support our ability to keep doing what we do by buying through the links on the site.
I did get a GRX crankset to replace the Praxis on my Revolt and then put a 4iiii left side 105 crank arm on it as my groupset is a 105 as well. But you can get a power meter installed on your GRX 810 crankarm through the factory install programs with a pretty quick turnaround. Power Meter City can set you up for Stages through this link and 4iiii through this one. Steve
I may have missed it in your review but do you cover whether or not the Quarq power meter will allow a cycling computer to display torque effectiveness and pedal smoothness? I’m in the process of buying a new bike and the shop recommended going with the Quarq spider on with cranks and bottom bracket on an Ultegra Di2 bike, it seems like a big expense with little to no upside compared to a single crank arm pm or even a downgrade if these data fields are not available. I have the left crank arm pm from Stages on my current bike and those data fields are great motivators in keeping my pedal stroke smooth and consistent.
Steve, a few reactions. 1) you may have misheard what your shop told you or the shop salesperson doesn’t really understand power meters but the Quarq bolts to the chainrings not the cranks or bottom bracket, 2) torque effectiveness and pedal smoothness may motivate you but they are rather worthless metrics and have not shown to have any correlation with power output. These metrics were created by Garmin to help market the Vector power meter pedals. 3) With a left-only power meter, you’re only measuring these metrics for your left side. 4) Quarq power meters don’t provide these metrics. Favero and Garmin power meters (both pedal power meters) do. 5) I’d suggest you focus on your watts as the primary metric and the only one that really matters to going faster. Better on-bike training, weight lifting, nutrition and sleep will improve your power output as measured by your watts. The other Garmin metrics like L/R balance, the two you mentioned, and the others in their analytics package don’t correlate to your power output. It’s good marketing but has no performance effect.
Bottom line, I’d suggest you move your Stages left crank to your new bike and avoided the bike shop upsell attempt. Steve
Thank you for the fast response. The bike I’m buying comes with Ultegra Di2 so if I went to the Quarq power meter I would have to also buy the crank arms and the DUB bottom bracket, definitely not what I was planning and the more I think of it the worse it sounds. I actually do use power output as my main focus but those other fields just made me aware of how inconsistent my pedaling had been, if nothing else it motivates me to put out more power as my torque effectiveness tends to increase along with power. I was considering sending the new cranks to 4iiii to have sensors installed on both sides but apparently that would also be a waste, I would love to have the data on both of my legs but as you mentioned there is no genuine benefit or way to ensure accuracy unless I go with pedals. Thanks again, looks like I’ll be sticking with the left crank arm.
Great review and great web site in general – I feel like I discovered a gem, and very much appreciate the analytical and no-nonsense description of what is going on across the board.
I have an older bike, a 2003 Trek Fx 7700, and can’t find any information on compatibility with the crank-based power meters, any idea how I would go about figuring out if I can install one of them?
Yiannis, Welcome and thanks for your kind feedback. Depends what kind of crankset you have. That bike originally came with a Shimano Deore XT groupset though I’m not sure what crankset you have on your bike now. You give Power Meter City a call and ask Josh (tell him I said hello!) if one of the modern left-arm Shimano cranksets will fit on your bike. Otherwise, go with power meter pedals with the sensor only on one side. Those will fit any crankset. Steve
Hi steve, thanks a lot for your excellent review, i use power tap pedals in one of my bikes and AXS power meter in the other one, the average power bettween them are 20 watts, i think that is really a big difference, do you think there is a problem with one of them? Or this difference can be normal.
Juan, I assume you put the Powertap pedals on the bike with the AXS and did a 30min or longer test to determine this difference? If they were both calibrated and this wasn’t a short segment spike difference then clearly there is a problem with one of them. SRAM bought Powertap and while they don’t make those pedals anymore, they may still service them. And of course, SRAM’s Quarq division makes the AXS. I’d put a call into SRAM or a SRAM dealer and see if they can help you figure out which one needs to be fixed. Steve
There is so much comprehensive information here and the fact that there are discount codes is just icing on the cake!
I just ordered a 4iiii left sided pm from Power Meter City.
Thank you
Hi Steve, very informative and helpful in narrowing the options down. Thanks.
The left side 105 crank arm power meter seems a good option, however I am concerned that there may not be enough clearance between the sensor and the stay on my new Trek Domane. In your experience, do the height profiles differ between the 4iiii and Stages? Have you heard of any such fitting issues?
The reason for my concern is that I found I was unable to mount the wahoo cadence sensor on my crank arm, because of inadequate clearance, and ultimately had to attach it to my shoe laces.
Jim, the latest models of the 4iiii crank arms have sensors that are a good deal thinner than the Wahoo cadence sensor.
Per this article from Josh Matthew who runs one of my recommended stores Power Meter City, “the 4iiii PRECISION 3 uses a new, slim sensor that is only about 5 mm thick. This means, you only need close to 7 mm of total clearance with the PRECISION 3 (vs. 10 mm for the Stages). This renders most incompatibility issues a thing of the past.”
I can’t say for sure but I’d expect the new 4iiii should fit on a relatively new bike like the Trek Domane if you’ve got the 7mm or so of clearance that Josh describes. Steve
have you tested out the new generation? i’ve heard it isn’t as reliable as the 2nd gen. i want to buy it but with the dropouts, laggy/jittery data in cadence and power makes me wonder how accurate it really is. any experience? i want to get this on my grx left side crankarm. just skeptical with few reviews and mostly negative.
Jonathan. I haven’t. Not sure what you’ve heard or where you’ve heard it from. The test results I’ve seen from GPLama shouldn’t bother you unless you are a high level track athlete that cares about 1 second delays – the segment power numbers for the units he compared the latest gen 4iiii to are well within the claimed accuracy range. And the review that included testing from VeloNews done by Ben Delaney whose been doing this kind of testing for years in a way that’s relevant for amateur racers and the rest of us didn’t have any issues with the unit. If I’m missing negative reviews, please send the links to me at [email protected] and I’ll look at them and let you know what I think. Steve
hi steve, thanks for the reply. yes i saw GPLama’s recent review. i didn’t want to purchase this until i saw either his review or DCrainmaker. sorry when i meant mostly negative, i saw some on reddit, 4iiii’s facebook and the comments on GP’s youtube comments. they said they’d stick with gen 2, no reason to upgrade. it’s like a step backward being it gen 3. i’m not a high level cyclist but i do love numbers/data and have my power set at instant power or 1 sec updates. i have the power tap p1 pedals and very happy with those. maybe i’m overthinking but after seeing the comparison’s it kind of turned me off if you know what i mean.
Jonathan. I agree no reason to upgrade from either the 4iiii Gen 2 or Powertap pedals if they are providing you consistent power readings that help you train. GPLama’s power meter reviews can be a bit overly sensitive to things that don’t really matter for most cyclists. Comments on forums can be from people who have limited experience comparing different units or using a robust testing protocol. For the most part, power meters are mature technology whose accuracy and consistency serve most everyone’s training needs. Power meter location, features, and price separate them now.
I’m also a bit geeky when it comes to numbers and data but from a training standpoint, I’d suggest that focusing on average power readings less than 3 or 5 secs can add a great deal of “cognitive load” without adding any training benefit. Best, Steve
thanks steve! really appreciate it, gives me peace of mind. the reason i consider 4iiii is for the low profile to fit my future gravel bike and enough clearance for mud as well. i may consider gen 2 if there is enough clearance too. i have shimano xtr pedals so i won’t need the powertap pedals. i considered the garmin xc100/200 but very expensive and pedal strikes from higher stack is a concern. would be really awesome if favero made mountain bike spd compatible pedals. seems affordable and reliable.
I’ve only just stumbled across this site and am loving it.
Thought I’d share my take on single sided to dual sided power meters. For years I rode with a single sided 4iiii and was happy with it, however the bike that was on got stolen and when I replaced it I decided to try a pedal based system and went for the Favero.
What I found was my imbalance varies depending on how much power/ which training zone I’m in. This can have quite a big difference when I am trying to hit certain zones. If my imbalance was consistent there are tools within the 4iiii to correct the numbers but because of the drift in balance as I put out more effort they become less and less accurate.
Tracy, I haven’t seen any data that suggests they report differently. 4iiii just introduced connectivity with Apple’s “Find Me” tracking software so that’s a nice plus. Otherwise, I’d shop around to see if there’s a better deal on one vs. the other going on now with the Labor Day weekend sales in place. You might even want to consider selling your DA crankset with the power meter and get a DA (or Ultegra) crankset w/o a power meter but in your preferred size and then send the left arm to 4iiii to have them mount the power meter sensor on it. Cheers, Steve
Steve
Thanks for your quick response. I am planning on selling the Dura Ace/Specialized crankset as it is one size too large and buying a DA 170mm and sending the left arm to either Stages or 4iiii for PM installation. I just wanted to see if your had a preference based on all of your research.
BTW- I really appreciate all of the well researched articles you and your team are providing an have based several buying decisions on your recommendations. Keep up the great work.
Kind of a unusual question here but I can’t seem to easily find an answer for this, or maybe I’m not phrasing it correctly for a Google search. Have you noticed if having a stiffer wheelset on your bike will give you higher wattage readings on your power meter? I just put a noticeably stiffer rear wheel on my bike and it seems like my max wattage has increased slightly, of course there could be multiple factors at work here but was curious if this is something you or your fellow testers have encountered in your testing?
Steve, we’ve never experienced that. As you suggest, could be a lot of factors, including that you are losing less power through a stiffer wheel than you were before with a less stiff one. I’d also suggest you zero offset the power meter at the beginning of each ride. Steve
Steve F –
I used the same Favero Assioma Duo’s on my 2016 Trek Domane with stock and later Hunt UD50 wheels, as well as on my current Pinarello Dogma F, equipped with Princeton Carbon Works 6550’s which are much stiffer than the Hunts (and a stiffer frame than the Domane).
My overall power output is noticably higher on the Dogma (I should hope so!), so I think your question is kind of a yea, any equipment that allows you to put more power through the pedals will be detected, kinda like making mods to a car and measuring on a dyno.
Thank you Jordan for the response and congratulations on the Dogma F, must be a lot of fun to ride and those wheels must be pretty damn amazing as well.
With the caveat that I haven’t tried crank or spider alternatives, I’ve been using Favero Assioma Duo pedals for the past 2+ years and absolutely love them. I’ve taken them off and traveled to Spain and Italy and used on rented bikes there without a hitch. I think the price and/or value proposition is strong. Can’t speak for other bike computers/ecosystems, but they work flawlessly with Garmin. One of the very few products I’ve purchased, for any purpose, that I thoroughly endorse full stop.
hi steve! thank you for the amazing review! quick question – what’s the difference between these two?
https://www.merlincycles.com/en-us/4iiii-precision-30-ultegra-r8000-powermeter-300371.html
https://www.merlincycles.com/en-us/4iiii-precision-30-ultegra-r8100-powermeter-299582.html
Elena, the r8000 uses the 11-speed crank; the r8100 will uses the 12 speed crank. The power meter will be the same as will the fittings to your crankarm spindle. You can use either. Steve