Whenever we talk about cycling, terms like aero, lightweight, stiff, or low friction come to mind. Athletes often purchase such upgrades because of “free speed.” This means maximizing your current fitness level by increasing efficiency and minimizing energy loss. As such, things like aero wheels, aero helmets, ceramic bearings, and high modulus carbon fiber are mainstays in the peloton or transition area. Such “free speed”, ironically, often comes at a high (monetary) cost. While there’s absolutely nothing wrong with purchasing these upgrades (as long as you have the means), I’d like to suggest an upgrade that will have a higher ceiling in terms of return on investment (ROI). Buy something that will allow you to train better, race smarter, and maximize your gains even more. A power meter, hands down, is one of the best upgrades you could ever purchase for your bike. It’s a tool that allows you to pace yourself properly, manage training volume/intensity, and monitor progress more effectively.
What is POWER?
Power is the amount of work generated in a given unit of time. In simpler terms, it’s the how far and how fast you can move an object. In cycling, power has two components, force and cadence. To increase your power output, you either exert more force (by selecting a heavier gear), or pedal faster (increasing cadence).
How do you use a POWER METER?
Most people are familiar with the humble cyclocomputer. Most models measure our time, distance, speed, and cadence. While this device might be enough for most recreational riders, it comes up short if the athlete wants to maximize each training session he does. The problem when looking at distance or time is that the overall load cannot be analyzed. A 1hr ride covering 25km on flat roads will be very different from a 1hr hilly ride covering the same distance. The intensity and effort are not shown by the numbers on a simple cyclocomputer.
Why do I need a POWER METER?
Measuring power gives us 3 main advantages:
1. It’s an excellent pacing tool.
Most people use effort to pace themselves. The problem with this is that most people, especially newbies, don’t have a good sense of feel yet. For example, if I ask someone to run at an easy effort for a 2hr ride, the term “easy” will seem very different at the start of the ride compared to the end of the ride. Overzealous athletes will tend to go out too quickly only to suffer towards the end. While training/racing by feel is an important skill everyone must hone, it still needs to have an objective metric (i.e. wattage).
What about speed? Speed is not a very good indicator of intensity especially when wind, road conditions, and terrain come into the picture. Maintaining 30kph against a headwind, on hilly terrain, will be a lot tougher than holding 30kph in flat and calm conditions. Using it as an absolute means to pace yourself will be very difficult.
Power is the gold standard in gauging effort. Unlike speed, it is independent from external variables; it is actual output generated by the rider. This makes it an excellent tool for gauging effort and intensity. Wattage numbers give us a clear picture about how hard we’re going and whether it’s sustainable or not. Let’s assume you can sustain 200w over a 40km course. Over that distance, your goal is hold wattage within a particular range (e.g. 180-220w) to result in an average wattage of close to 200w. This means staying as close as possible to 200w but operating within a particular range when tackling hills or descents. This will allow you to nail the best possible time without gassing out or bonking. Remember, for a given course/condition, higher power will always result in faster speed.
2. It helps us manage our training load.
Training with a power meter allows you to keep track of your training load effectively. As I mentioned earlier, not all rides can be measured solely by time or distance. Hilly courses will log a shorter distance but it requires more effort. An easy ride might have the same duration as a hard ride but will obviously be more intense.
Power meter data will give you what’s called the “Training Stress Score” or TSS. Don’t be intimidated by the terminology it as it actually simplifies everything! TSS quantifies the training load/effect of each ride. Every session gives you a number based on how hard and how long you pushed. A short hard ride will generate a higher TSS value than a slightly longer but easier one. This gives you some insight as to how each training session affects you. Keeping track of TSS across several days or weeks allows you to monitor your training block.
3. It allows us to monitor progress effectively.
“It never gets easier, you just get faster” – Greg LeMond
Let’s face it, “race pace” will roughly feel the same even if you’ve improved tremendously. The difference lies in how much faster you go for the same effort. As I mentioned earlier, unless we keep riding the same course under the same conditions every single day, a change speed is a somewhat unreliable measure of an increase in performance (or lack thereof). How then do we know if our training program is working?
A scientific yet simple way of measuring progress is to think in terms of Input and Output. Input here is heart rate (HR) while Output is power. Heart rate is a good indicator of effort. In fact, in the absence of a power meter, HR is a pretty good means of pacing oneself. When coupled with a power meter, training with HR allows you to see if you’re producing more wattage for the same effort. For example, say you were producing 180w while maintaining 130bpm several months ago. After training consistently over several training blocks, 130bpm now generates 220w. This means you’re going faster for the same effort. That’s a 22% increase in performance!
Ultimately, in races, we will be judged based on how fast we go and not by how much effort we put in. Having an objective means of monitoring progress is very important. If we keep track of what works and what doesn’t, we’ll be able to maximize the time we spend training.
What POWER METER do I NEED?
It all depends on your current setup. Different brands offer a plethora of meters that can confuse any athlete (especially newbies). I’ll discuss a few of the more popular ones.
A. Hub Based
Hub based meters are laced on to your rear wheel instead of your usual rear hub. This is one of the pioneers of power meters but has been superseded by newer variations of the technology.
PROS: Accurate and consistent power measurement. Easy to switch between bikes.
CONS: Battery life isn’t that good. Tedious to replace/maintain. Having different sets of training and racing wheels requires two meters.
WHO IS IT FOR? For people who have two or more bikes and a single pair of wheels (racing or training).
B. Crank Based
Crank based meters have two main variations: arm/spindle based and spider based.
Arm/Spindle based meters (above) are simple, easy to install, add-ons to existing cranks. These are usually slightly cheaper than spider based meters but only measure power on the non-drive side. Only a few arm based meters measure both left and right wattage but are prohibitively expensive.
Spider based meters (above) measure wattage at the actual spider (the part between the crank and the chain rings. This means power is measured both for the left and right legs. Most of the time, these need to be professionally installed but are usually bombproof once set in place.
Both meters can easily be transferred between bikes as long as they accept the same type of crank (depending on their respective bottom bracket types).
PROS: Easy to Install, A Cheaper Upgrade.
CONS: Battery life is short. Power is measured on one side only. Waterproofing sometimes becomes an issue.
WHO IS IT FOR? If you have an existing crank that’s compatible with the add-on (e.g. Shimano Ultegra), this is the way to go. It’s a quick and easy upgrade.
PROS: Accurate. Consistent. Good waterproofing. Chainring compatibility isn’t a problem. Left and Right Power and Balance are measured.
CONS: A bit more tedious to install.
WHO IS IT FOR? If you want a no-frills, “set it and forget it” option, this is for you. Not only does it give you both left and right power, it also tells you whether your pedaling technique is balanced or asymmetrical.
C. Pedal based
Pedal based meters have strain gauges within the pedal body. While most would assume that this means “measuring power close to the source” thereby contributing to better accuracy, quite the opposite is true. Such meters measure wattage at the pedals and employ complex algorithms to estimate power at the spider level. This results in a rather significant percentage error in terms of accuracy. Based on the tests we’ve conducted on a particular type, the difference is not linear. This means it’s not as simple as adding 10% (or any value) to your readings. Such a setup usually overestimates low wattage efforts and overestimates high wattage efforts. This can pose huge problems when switching between meters.
PROS: Transferable between bikes.
CONS: You'd usually need special tools to install/transfer. Accuracy is rather bad. Pedal spindle needs to be replaced every couple of years. Prone to damage from impact. Only compatible with Look cleats.
WHO IS IT FOR? If you have multiple bikes with varying crank lengths or crank types, this may be a good fit for you. Take note that you will still need some special tools and bike know-how to transfer pedals between bikes.
We know all the options seem daunting at first. But don’t worry, we’re here to help. Click on the link below, fill it out with the required information and we’ll make the best recommendation based on your setup!