by Matt Russ

Bicycle power meters are arguably one of the most influential training technologies to come along in cycling in decades. Once considered a mythical device reserved for professional cyclists and wealthy amateurs who talked about metrics such as normalized power and variability index, power meters are now accessible to virtually every cyclist.

High-quality bicycle power meters are available at much more affordable price points than they were in the past. They have also become easier to install, pair, calibrate, and use. Modern power meters can communicate with a wide range of cycling computers, smartphones, tablets, and training platforms.

Perhaps best of all, power meters have opened the door to an enormous range of indoor cycling and structured training options.

However, buying a power meter can still be confusing—and the wrong choice can lead to buyer's remorse.

There are several different types of power meters, and compatibility with your bicycle, crankset, pedals, drivetrain, and training equipment can make the decision more complicated than simply choosing the most expensive or highest-rated model.

Before buying a cycling power meter, ask yourself these five questions.

1. What Is My Budget for a Power Meter?

Start by establishing your price range. A budget within roughly $100 of your target price is a good place to begin because it can immediately eliminate a number of options and make the buying decision easier.

Power meters vary considerably in price depending on their design, accuracy, features, and installation method.

The least expensive power meter isn't necessarily the best value, however.

It's also important to understand how the power meter actually measures power. Some devices estimate power using environmental and riding variables rather than directly measuring the forces being applied to the bicycle.

For cyclists who want reliable power data for training, I recommend looking for a strain-gauge-based power meter that directly measures the forces being applied to the crank, pedal, or other component and converts that measurement into watts.

The goal isn't necessarily to buy the most expensive power meter. It's to buy a power meter that provides the level of accuracy and functionality you actually need.

2. How Much Power Meter Technology Do I Really Need?

As the price of a power meter increases, you will generally find more features and additional data.

Depending on the system, these may include:

• Left/right power measurement
• Multiple strain gauges
• Pedal-stroke analysis
• Advanced cycling dynamics
• Higher claimed accuracy
• Additional data metrics
• Bluetooth and ANT+ connectivity
• Integration with training software

But do you really need all of those features?

For many cyclists, the answer is no.

If your primary objective is to monitor average power, normalized power, personal bests, training load, and performance trends, you may not need an extremely sophisticated system.

In fact, I find that many cyclists are perfectly happy with a power meter that provides straightforward and consistent power data.

Bluetooth and Training Software Compatibility

Connectivity is an important consideration, particularly if you plan to use your power meter for indoor cycling.

A power meter that supports Bluetooth and/or ANT+ can connect to a variety of cycling computers, smartphones, tablets, and training platforms.

If you want to use indoor cycling applications such as Zwift or TrainerRoad, compatibility with your preferred training platform should be one of the first things you check before purchasing.

Don't assume that every power meter will work seamlessly with every device or application. Check the manufacturer's compatibility information before you buy.

3. How Many Bikes Do I Want to Use My Power Meter On?

This is one of the most important questions to ask before purchasing a power meter.

Some cyclists have one bicycle. Others have a road bike, triathlon or time-trial bike, gravel bike, mountain bike, or dedicated indoor training bike.

If you want to measure power on multiple bicycles, portability may be more important than some of the advanced features offered by a particular power meter.

Crank-based power meters can be an excellent option, but moving one between multiple bicycles isn't always practical. Unless your bikes use the same crank model and crank length, compatibility can become an issue.

Pedal-Based Power Meters

Pedal-based power meters are among the most portable options available.

You can generally move the pedals from one bicycle to another relatively easily, assuming the bikes use compatible pedal threads and you are using the same pedal system.

For cyclists who own multiple bikes, this can make a pedal-based power meter an attractive option.

Crank Based Power Meters

Power measured at the crank arm or spider can be a bit more complicated.  A single crank arm replacement only needs to be the correct brand/model and length and the replacement can easily be done by the rider.  Some brands offer "factory replacement" in which you mail in your single crank arm and they factory affix the power meter to it.  Power meters in the spider or axle require a bit more knowledge and we will get into that in the next section.

4. Will the Power Meter Work With My Bike?

This is where purchasing a bicycle power meter can become confusing.

Most crank-based power meters attach to the crank in some manner, whether at the crank arm, chainrings, or spider of the crankset.

Unfortunately, identifying the correct power meter isn't always as simple as knowing the make and model of your bicycle.

You can have:

• The correct crank brand but the wrong crank length
• The correct crank length but the wrong chainrings
• The correct crank but the wrong bottom-bracket interface
• The correct brand but the wrong crank model
• A technically compatible power meter with insufficient frame clearance

The first thing to understand is that you need specific information about your crankset, not simply your bicycle.

Know Your Exact Crankset

Bike manufacturers can change component specifications during a model's production cycle. Two bicycles that appear to be the same model may not necessarily use the same crankset.

And don't assume that having a Shimano or SRAM drivetrain means you have a Shimano or SRAM crank.

For example, a bicycle equipped with a Shimano drivetrain may have an FSA crankset. This is relatively common.

Before purchasing a crank-based power meter, identify:

1. Crank manufacturer
2. Exact crank model
3. Crank length
4. Chainring configuration
5. Bottom-bracket interface
6. Available frame clearance

This information can make the difference between a power meter that installs perfectly and one that doesn't work with your bicycle.

Check Power Meter Clearance

Frame clearance is less of a problem than it once was because modern power meters have become smaller and thinner.

Nevertheless, you should always check the manufacturer's compatibility information before purchasing.

Many manufacturers provide detailed specifications and clearance requirements on their websites. If you're uncertain, measure your bicycle and compare those measurements with the manufacturer's requirements—or have a qualified bike shop verify compatibility.

5. How Old Is My Bike and Drivetrain?

This final question is often overlooked, but it can have a major impact on the value of your purchase.

If your bicycle is several years old and you already know that you're likely to replace it soon, I would think twice before purchasing a crank-based power meter specifically for that bicycle.

Why?

Because you don't know what crankset your next bicycle will use.

A power meter that fits your current crank may not be compatible with the crankset on your next bike.

Pedal-based and wheel-based power meters can offer greater flexibility when you're planning for a future bicycle.

You should also consider the age of your drivetrain.

Even if you intend to stay with the same drivetrain manufacturer, your current bike may use a generation or two-old crankset. Power-meter technology, like other cycling technology, continues to evolve.

Check Your Chainrings Before Buying

There's another potential money-saving opportunity here.

Check the condition of your chainrings before purchasing a crank-based power meter.

If your chainrings are worn and you're going to replace them soon anyway, consider a power meter that includes new chainrings.

You may be able to combine two purchases into one and save money in the process.

What's the Best Power Meter for You?

There is no single best bicycle power meter for every cyclist.

The best power meter is the one that fits your budget, works with your bicycle, provides the features you actually need, and can be used in the way you intend to train.

Before you buy, consider:

• Budget: How much are you comfortable spending?
• Features: How much technology do you actually need?
• Portability: Do you want to use the power meter on multiple bikes?
• Compatibility: Will it work with your crankset, drivetrain, and frame?
• Future plans: Are you likely to replace your bike or drivetrain soon?
• Training: Will you use the data with a cycling computer or indoor training platform?

A little research before purchasing can prevent a lot of frustration afterward.

The cheapest power meter may not be the best choice, and the most expensive power meter may offer features you will never use.

The goal is to find the right power meter for your bicycle, your training, and your budget.

Do that, and a power meter can become one of the most valuable tools in your cycling training arsenal.

Matt Russ enjoyed a professional coaching career spanning over two decades of working with professional endurance athletes. His athletes have achieved numerous regional, national, international and championship titles under his direction. Matt achieved the highest level of licensing by both USA Triathlon and USA Cycling, and was a licensed USA Track and Field Coach. His accomplishments include being named "Team USA" Coach for the 2011 Beijing World Championship. Head Coach and founder of The Sport Factory, a USA Triathlon Certified Performance Center, he has authored many articles on a wide variety of endurance related topics.