Looking to buy a power meter for your road bike to bring your cycling to the next level?
You’re on the right page.
Before you commit to buy a power meter, there are things you need to know such as the various types of power meters, how and where the power measurement is taken, and more importantly, which one is compatible with your current bike set up.
Yes, sometimes things can get complicated. But don’t worry as I’ll cover all of these in detail below.
A Quick Glance : Our Favorite Power Meters for Road Bikes
| Power Meter Model | Type | Accuracy | Best For |
|---|---|---|---|
| SRM Origin | Spider | 1.5% | Reliability |
| Power2Max NG Eco | Spider | 2% | Wide Compatibility |
| Stages | Left Sided | 2% | Budget Minded |
| 4iii | Left Sided | 1.5% | Shimano Cranksets |
| Quarq D Zero | Spider | 1.5% | SRAM |
| Power2Max NG | Spider | 1% | Campagnolo |
| Powertap G3 | Wheel Hub | 1.5% | Those with Many Bikes |
| Garmin Vector 3 | Pedal | 1% | Easily Swappable |
On This Page
Types of Power Meters for Road Bikes
Power meters can be placed on several locations on your bike.
Which kind you want depends largely on several factors, such as ease of installation, accuracy, and data type.
Let’s take a look at the different types of power meters that are on the market and how they stack up in terms of accuracy, ease-of-installation, and power data output.
1. Spider Based
Since SRM designed the first spider power meter more than 30 years ago, it has become one of the most popular styles of meters available.
They come in a wide variety of configurations, are designed to be compatible with the broad range of crankarm brands and chainring sizes that exist in the market today.
This versatility coupled with the fact that they are very accurate makes them an attractive option.
However, it should be noted that because they’re mounted onto the chainring, they can’t be easily removed and installed on another bike. You’ll have to remove the entire crankset.
Examples of Spider-based Power Meter : Quarq Dzero, Power2Max NG Eco, SRM Origin
2. Wheel Hub
Wheel hub power meters aren’t one of the more popular options out there today. In fact, only one company manufactures them, PowerTap, which was acquired by SRAM last spring.
They add more weight to your set up than other types of a power meter.
Installation is also not something you can do yourself. Since they’re located in the rear wheel hub, the wheel will need to be custom-built in order for them to be installed.
They do have their advantages though. They’re cheaper than other types, making them a great option for budget-minded cyclists.
And since they are incorporated into the wheel hub, you can easily swap between bikes, making this a great option if you have several bikes.
Example of Wheel Hub Power Meter : Powertap G3
3. Crank Arms
Like pedals, power meters that attach to the crankarms are easy to swap in and out, making them a great option for cyclists looking to use their power meters on multiple bikes.
These meters also offer several data options. They can be single-sided for left leg power only or double-sided, which allow you to measure left and right side power independently.
These are probably the lightest power meter today as they only add 30 to 40 grams of weight to your existing crankarms.
4. Pedal Based
Pedal-based power meters are easy to swap between bikes.
Compatibility also isn’t an issue here as they can generally attach to any crankarms.
However, you might need to change your cleats. The major manufacturers of pedal-based power meters, including Powertap, Garmin, and SRM use LOOK style cleats.
And while they stay clear of your drivetrain, they are also in a more vulnerable location as the pedals on a bike have a tendency to take a beating. These types of meters are usually sold as single-sided, which measures one side only, and double-sided options that offer left side and right side power data.
Examples of Pedal Based Power Meter : Garmin Vector 3
Cycling Power Meters Buying Guide
1. Existing Bike Setup
For most cyclists, power meters are an add-on purchase that comes after they’ve been on their bikes for a while.
Because of that, it’s important to understand that not all power meters will fit all bikes’ setup. You need to familiarize yourself with your bike before purchasing it.
Spider Based
Spider based power meters will also require you to know the brand of the crankarm and the BCD (Bolt Chainring Diameter) size of your chainrings.
BCD is the distance between the bolts that are across from each other on a chainring. Common chainring sizes include 110 and 130, 4-bolt Shimano, and Campagnolo. Since the spider-based power meter will replace your existing spider, it must match up with the chainrings that will attach to it.
Spider-based power meter manufacturers such as Power2Max and SRM offer many different variants that are compatible with a wide range of crankarm brands and chainring sizes.
Single Sided (Left Side)
If you plan on using a power meter that attaches to the left crankarms, you’ll need to know the brand of your crankarms. You can often find left-sided power meters for Shimano, SRAM, Campagnolo, or Cannondale crankarms.
You also need to match the length of your existing crankarms to the new ones. Crankarm lengths generally range from 165mm to 175mm.
Pedal Based
Compatibility for pedals is not usually an issue. Most pedals are compatible with most cranksets, and so most power meter pedals such as Garmin Vector 3 and SRM Exakt will be compatible with your bike.
Wheel Hub
For wheel hub power meters, you’ve pretty much got one choice as PowerTap remains the only manufacturer here.
You’ll need to either build a new rear-wheel or replace your existing rear wheel hub with the power meter.
Read More :
2. Accuracy
If you’re going to invest in a power meter, and it’s quite an investment ranging anywhere from $500 to $2,000, you want to know that it’s going to provide you with accurate and consistent data.
And since the goal of a power meter is to help you to improve your power output, consistency is just as important.
If the power meter is 1.5% off one day, you need it to be 1.5% off every day in order to get useful data. Keep in mind that different brands of meters offer different levels of accuracy.
Read More :
3. ANT+ and Bluetooth Connectivity
Older power meters transmit data using ANT+, which allows them to connect most bike computer systems such as Garmin. Newer ones offer Bluetooth connectivity, which allows them to connect to smartphones and tablets. Today, most power meters offer both options.
Decide what type of device you will be used to track your power output, then determine if you will need a device that offers Bluetooth, ANT+, or both. Most cyclists use a bike computer.
Read More :
There are some things to consider when making this decision. ANT+ power meters can connect with multiple ANT+ head units at once, while a Bluetooth power meter can only communicate with one head unit at a time.
4. Battery Life
I suppose it goes without saying that a power meter will need its own power in order to tell you how much power you’re producing.
Power for your power meter comes in two forms, USB charge, and coin-style batteries. Newer models and higher-end models such as the Stages for Shimano, Power2Max NG, and SRM Origin are mostly USB rechargeable today.
Coin-style batteries used in models such as Quarq Dzero and Power2Max NG Eco generally give between 200 and 400 hours of riding time before needing replacement.
5. Ease of Maintenance
The maintenance for a power meter isn’t particularly involved as bike accessories go.
They may require battery changes and firmware updates. This sounds simple, but you still want to make sure that swapping out a battery doesn’t involve a lengthy uninstall and reinstall of the power meter from your bike or worse, having to send it off.
Read More :
For example, older SRM’s require that they be sent back to the manufacturer for battery replacement.
You also want firmware updates to be relatively easy either through a USB cable or a quick Bluetooth connection.
6. Support and Warranty
Power meters are delicate pieces of electronics that need to be correctly calibrated and installed in order to work properly.
Although they are designed to handle the perils of being attached to a bike hurtling down the road through all manner of weather, they’re still expensive delicate pieces of electronics that can fail.
With that in mind, you’ll want a manufacturer that offers support when something isn’t working and replacement or repair for as long as possible if something stops working.
Look for manufacturers that offer some kind of warranty that will cover the manufacturer’s defects for at least one year. Also, stick to tried and true known manufacturers in the bike industry like Shimano, Power2Max, SRM, Garmin, and PowerTap.
These are companies that you know will stand behind their products and offer solid customer support.
Our Favorite Cycling Power Meters
SRM Origin
The Gold Standard of Power meters
- Very Accurate and Reliable
- USB Rechargeable Battery
- Very Expensive
If you’re super serious about improving your performance, then you want a super-accurate power meter. Look no further than the SRM.
SRM is one of the pioneers of cycling power meters, developing its first power meter all the way back in 1986.
Their latest model, the SRM Origin, uses a 144-point calibration method and its Auto-Offset feature to make this power meter as consistent and accurate as possible, to within 1.5%.
You also won’t compromise weight with this power meter. With its LOOK carbon crank arm, it weighs in at just 599g. The crank arm is also adjustable from 170 mm to 175 mm through its Trilobe Technology.
The SRM Origin also includes interchangeable spindles that make it compatible with virtually any frame.
Power2Max NG Eco
Wide Compatibility Across Many Brands
- Budget Friendly
- Automatic Zero Offset
- Non-Rechargeable Battery
Power2Max manufactures power meters for all the major crankset brands such as SRAM, Praxis, ROTOR, Shimano, FSA, Cannondale, Easton, and Campagnolo.
The NG Eco is one of Power2Max’s most versatile and budget-friendly options out there today. It combines left and right power measurements, comes with ANT+ and Bluetooth connectivity, and is accurate within 2% at a price point below other spider-based power meters such as the SRM Origin.
It is powered by a coin-style CR2450 battery that gets between 300 and 400 hours of battery life and comes with a 2-year warranty.
4iiii for Shimano
Best Value for Existing Shimano Cranksets
- Only adds 9g to Crankarm
- Supports Bluetooth and ANT+
- Short Battery Life
At $500, this power meter is a steal for cyclists who are already running Shimano Ultegra cranks.
Manufactured by Canada-based 4iiii (Shimano recently bought 4iiii), it measures left leg power with 1% accuracy. It’s lightweight, adding just 9g to the left crankarm’s weight, and can be installed in minutes.
It uses ANT+ or Bluetooth Smart to communicate, making it compatible with most bike computers and smartphones. Powered by a lithium-ion rechargeable battery, it packs around 60 hours of battery life.
For wider compatibility, you’ll have a choice of crankarm lengths from 165mm up to 175mm and is compatible with all existing Shimano R6800 and R8000 cranksets.
Stages for Shimano
The Choice of Multiple Tour de France Winners
- Only adds 20g to Crankarm
- Long Battery Life
- Non-Rechargeable Battery
If you’re looking for the best left-sided power meter for Shimano groupsets, then you know it’s going to be for Shimano DuraAce.
The DuraAce is Shimano’s top-of-line group of components for road bikes which you’ll often find on the bikes of pro cyclists such as Team Ineos, who has won multiple Tour de France in the past 10 years with 4 different riders.
This Stages power meter is accurate within 1.5% and only adds 20 grams to your bike. It has both ANT+ and Bluetooth connectivity, allowing you to connect to your cycling computer and your smartphone or even tablet if you’re riding indoors on Zwift.
It’s available for crank arm length from 165mm to up to 180mm.
Quarq DZero
The Latest from A Long Time, Reputable Brand
- Very Accurate Reading
- No Magnets Needed
- Very Limited Compatibility (SRAM and Specialized only)
The Quarq DZero combines the best that Quarq and SRAM have to offer.
Quarq started in 2008 in Australia before being sold to SRAM in 2011.
This spider-based power meter combines the Quarq’s DZero technology with SRAM’s DUB (Durable Unified Bottom Bracket) technology. The result is a power meter that is perfectly suited for those who’re already riding on SRAM components, especially the crankset.
It’s compatible with all SRAM crankarms with 5-bolt chainrings (10 and 11 speed). It also comes with a 2-year warranty. The Quarq DZero is powered by a coin-style CR2032 battery that provides about 200 hours of battery life.
Power2Max NG for Campagnolo
Designed Specifically for Campagnolo Fans
- USB Rechargeable Battery
- Auto Zero Offset
- Expensive
If you ride Campy components and you’re willing to spend a little more, then consider the Power2Max NG.
It’s probably the prettiest looking power meter for those using Campagnolo components. It comes with both left and right carbon crankarms, but minus the 4-bolt Campagnolo chainring, which you will have to purchase separately.
Campagnolo components tend to be the most expensive, and this power meter is no exception. While it may be priced on the premium side of things, it’s important to note that this model does give you a spider and left and right carbon cranks.
Accuracy is excellent at 1%, and it is powered through USB recharging. It also comes with one of the best warranties available. Power2Max has you covered for 5 years.
Powertap G3
The All-Time Favorite Wheel Hub Based Power Meter
- Wheels are Easily Interchangeable Between Bikes
- Very Accurate Reading
- Long Battery Life
- Wheelsets Needs to be Custom Built
Have multiple bikes and don’t want to invest in multiple power meters? Check out the Powertap G3.
Choosing a wheel hub-based power meter is a relatively simple task. Why?
Because there’s only one company that has figured out how to make them, and that company would be Powertap, which has been producing hub-based meters for the past 20 years.
It features accuracy to within 1.5% and is powered by a CR2032 battery with 200 riding time hours. The Powertap G3 comes with a 2-year warranty.
Perhaps the biggest lure of this power meter is its price. At $400, this gives you a power meter at a fraction of the price of other options on the market.
Garmin Vector 3
Easily Swappable Between Bikes in Minutes at Home
- Ideal for those with Multiple Bikes
- Measures Left and Right Power Independently
- Vulnerable During Crash
Pedal-based power meters offer the advantage for you to easily swap between bikes.
If this is what you’re after, then you can’t go wrong with the Garmin Vector 3. It is available as dual-sided, with strain gauges in both pedals, or single-sided in the left pedal only (Garmin Vector 3S).
It supports both ANT+ and Bluetooth connections and is accurate to within 1%. If you’re a data geek, this gives you access to all of Garmin’s cycling data points such as power phase, peak power phases, and more for a detailed deep dive into your performance and power output.
Leading Power Meter Brands
1. SRM
SRM was the first company to deliver a viable power meter to market. Since then the company has expanded its product lineup, improved its meters, and has now included user-serviceable batteries.
SRM manufactures crankarm based power meters, either as full systems or modular. They come as aluminum or carbon and deliver top-quality accuracy.
SRM power meters are not cheap but if they are reliable enough for pro teams, they should be more than enough for us.
2. Quarq
Quarq designed their first power meter back in 2006 in Australia. The company name is a deliberate misspelling of quark, referring to a speedy subatomic particle.
The first Quarq power meter was released in 2008 and since then the company has gone from strength to strength and being bought over by SRAM in 2011.
Most power meters from Quarq are crankarm based that work with the common bottom bracket systems such as GXP and BB30. Products include Quarq DZero, Quarq DFour91, and those specially designed for SRAM Red AXS groupsets.
Read More : SRAM Red vs Shimano Di2 – Which One is for You?
3. Stages
Stages is an American company that does things slightly differently than SRM or Quarq.
They take pre-manufactured cranks and machine their power meter units into them. It is a novel idea that seems to work.
Stages power meters come as an entire crankset for Shimano or as separate left-side crankarms.
4. Power2Max
Germany’s Power2Max was founded in 2006. Their original aim was to develop an affordable power meter that they themselves would like to ride, and in 2010 they achieved just that with their very first power meter.
Since then, the company has widened its product portfolio and has been ridden by Team Movistar up to 2019.
Power2Max power meters have wide compatibility with many leading crankarms such as Shimano, SRAM, Rotor, Specialized, and Cannondale. They include road, track, and mountain bike units such as the NG Road, NG Eco, and Type S.
5. PowerTap
PowerTap was one of the pioneers, having begun developing theirs back in the 1990s. It, along with SRM, was the only company offering power meters and bringing them to market. Their goal was to make their power meters more accurate and more affordable than SRM, and they delivered.
Now owned by Quarq, PowerTap manufactures crankset, pedal, and hub-based power meters. Products include PowerTap Pedals, PowerTap G3 Hub, PowerTap C1 chainrings, among others. PowerTap is the only company to manufacturer all of the currently available types of power meters.
