Beginner’s Journey to Power Meter Training and Racing: Part 1
Beginner’s Journey to Power Meter Training and Racing: Getting Started
Once only within the reaches of pros, elite amateurs, and cyclists with more money than they knew what to do with it, recent price drops have made power meters more accessible to more cyclists. Lead by companies like Stages Cycling, prices for power meters have plummeted in recent years causing this piece of cycling technology to move from being a luxury towards being a must have for any cyclist wishing to take their training seriously.
It was the same story with heartrate monitors in the 80s and 90s, and a common theme in the tech world. Prices dropped and heartrate monitors became more and more accessible to the everyday cyclist. Now its the power meter’s turn. Power meters are moving in thanks to lower prices and are replacing heartrate monitors as the future of training for cyclists.
Over the coming weeks, I will be taking you on a journey through the world of power meters. You will follow me on this journey as I work on going from a complete power meter newbie to a competent power meter user, sharing my experiences and gained insights along the way.
Along the way, we will look at:
- how a power meter works
- the options available
- how to set your training zones
- what all those numbers mean
- how to train with a power meter
- how to race with a power meter
- and more…
Many people are hesitant about jumping into the world of power meters. They are intimidated by the all the numbers and data and fear that over analyzing their training will take away from the joy of riding. The goal of the series is to demystify the world of power meters. I aim to show that power meters are not something to be feared and are no longer only for the pros but rather that they should be embraced as a training tool for the average cyclist.
Unlike the traditional “Beginner’s Guide to…”, this series is not written by an expert trying to dumb a subject down. This wont be like a university lecture hall. Instead, during this series we will learn about power meters together in a way that is not intimidating and easy to understand.
Benefits of Training with a Power Meter
There are many benefits to training with a power meter and I could dedicate a whole post to the many reasons to train with a power meter. Most importantly, knowing your power is a quantitative, repeatable way to assess training. Training to power is far more reliable than other methods of measuring training effort like heartrate and speed, which are affected by other variables. Power is completely dependent on the rider and unaffected by external factors making efforts easier to measure and repeat.
In the past, the main downside of power meters was their enormous cost. But with costs continually dropping, and many reasonably priced options now on the market, this argument holds less and less traction.
How Power Meters Work
A power meter is a device that measures the power output of the rider.
Power is determined using the formula: power = force x distance / time. Or more simply: power = force x velocity. Power meters calculate the riders power output by multiplying the speed of movement (rotation of the cranks or hub) by the size of force applied by the rider (how much the rider can bend something).
Power meters use strain gauges to measure the amount of force applied by a rider to a certain component by measuring how much the rider bends a piece of metal with known properties like a crank arm, crank spider, or a torque tube inside a hub. Strain gauges are placed on a piece of metal and bend with the metal. The strain gauges contain a coil of wire which has an electrical current running through it. As the wire bends with the metal, more or less current is able to run through it, which tells the power meter how much the piece of metal has bent.
The amount of displacement is measured in Newtonmeters and is then multiplied by the speed of an event, either the speed of a rotation of the cranks (cadence) or hub. The resulting number is converted from Nm/s to watts (1 Nm/s = 1 w) and appears on the screen of your head unit as your power number. But of course a power meter is constantly doing these calculations and transmitting them to your head unit.
Power Meter Options
There are a large number of power meter options on the market today with a variety of companies now have power meter offerings. Rather than going into detail about all the specific options on the market (if you want to check out this post from DC Rainmaker), we will look at the most common placements for power meters and some of their pros and cons.
The power meter is located in the rear hub of the bike and uses strain gauges attached to a torque tube to measure torque. Powertap is the only company that offers this placement, who, thanks to years in the industry, offer products trusted for their reliability and accuracy.Pros: easy to move between bikes; relatively inexpensive
Cons: difficult if you have different wheels for training and racing or multiple styles of bikes; come with a weight penalty
Crank based power meters are attached to the crank arms and can be thanked for the recent plummet in power meter prices. Stages was one of the first companies to offer a crank based power meter with their left-only meter but have since been joined by companies such as electronic leaders Pioneer and the small Canadian company 4iiii.
Pros: relatively inexpensive; relatively easy to switch between bikes
Cons: limited to aluminum crank arms; not all offer true left/right power
Crank spider Based
Thanks to SRM, the original power meter manufacturer, crank spider based power meters are often considered the “gold standard” when it comes to power meter accuracy. They measure the amount of flex in the chain rings. Apart from SRM, there are also options from Quarq and Power2Max. Often the priciest options on the market but thanks to increased competition even SRM’s prices have dropped recently.
Pros: SRM is considered the “gold standard”; work with any crank arm material
Cons: expensive; need to be recalibrated at the factory if switching from default rings
In recent years, pedal based power meters have received the most fan fair and media attention thanks to the long expected release of an option from Garmin as well as the recent announcement of a new product from Powertap. Pedal based power meters measure the amount of flex in the pedal axle.
Pros: easy to move between bikes; useable with any crank arm material
Cons: expensive; rider weight limits; in a vulnerable location
There is no perfect power meter for every cyclist. Everyone has different requirements for a power meter. When choosing a power meter, think about how you plan on using it. Will you use it on multiple bikes? Do you use different wheels for training and racing? What is your budget? etc.
Also remember that the most important thing for training is that a power meter is accurate relative to itself. One power meter might be more accurate than another, there are many variables that affect accuracy so they wont all give the same numbers, but that fact does not affect your training. Unless you are trying to compete with your friends to see who can put out the highest max power, the most important thing is that your power meter shows consistent numbers from one effort to the next.
Once you have chosen a power meter you are almost ready to go. In just three easy steps you will be ready to hit the road. First you need to install the power meter on your bike by following the manufacture’s instructions (or getting your local bike shop to take care of it). Second, you have to pair the power meter with your head unit of choice, and, finally, you need to calibrate or zero the unit using your head unit.
Stages Cycling has been kind enough to provide me with a power meter to use throughout this series. But any power meter will do for following along during this series, cause, as I said above, the most important thing for training is that your power meter be accurate relative to itself.
So you’ve chosen your power meter and have it installed on your bike, now what? The next step is to do some tests in order to find your training zones but before we get to that, go out and ride your bike. Before getting too serious with training zones, just ride your bike with your new power meter, have some fun, and get an idea of what sort of numbers certain efforts produce.
Special thanks to Stages Cycling for supporting this series by providing a power meter for use!