Power-to-weight ratio is the “great equalizer” in cycling. It’s how cyclists can be compared to one another and how you can measure your own progress over time. The ratio is an expression of watts/kg. Power, in watts, is your functional threshold power, FTP, or the amount of power you can sustain for an hour. (If you’re unsure of your FTP, you’ll soon be able to schedule a 20-minute time trial in our new CompuTrainer Studio.)
Cyclists have several ways to increase power-to-weight ratio: we can either increase power output through training or decrease body (and/or bike) weight. This winter, we’ll discuss ways to reduce that lower number and, if you join us in our CompuTrainer Studio, we’ll work together to increase that top number.
All this assumes, however, that you’re riding with power. This is one benefit to training in our CompuTrainer Studio all winter long: your workouts are all power-based. But you’re not limited to training indoors or only in winter. There is, in fact, a full array of power devices on the market. With new products being introduced just about every quarter, we’re seeing power devices increasing in accuracy and becoming more affordable.
We’re going to explore several options of power meters, based on where they are on your bike.
A Note on Connectivity
Power meters use the ANT+ standard, meaning that you can use these power meters with your (ANT+ equipped) Garmin cycling computer.
Some of the newer devices are equipped Bluetooth, turning your smartphone into a computer and eliminating the need for a separate computer.
Crank-Based Power Meters
If you follow the pro tours, you’re seen the SRM computers on the pros’ handlebars. Since most of us don’t have the benefit of sponsorship, we were delighted when SRAM brought affordable versions of crank-based power meters to market. The crank-based power meters replace your existing crank spider, so you’re able to swap out chain rings. SRAM is known for its customer service and, with its headquarters here in Chicago, we’re able to get replacement parts quickly.
SRAM’s Quarq eliminated the major disadvantage to crank-based power meters, which was affordability. Now, the only disadvantage is that swapping the power meter from bike to bike can be (but isn’t necessarily) complicated. Talk with our mechanics and they can help you determine whether you can easily swap the Quarq from bike to bike.
Rear Hub-Based Power Meters
PowerTap was the first on the scene to provide an affordable option to the SRM’s hefty price tag. They still own the market on rear hub-based power meters, but this isn’t a bad thing. PowerTap is known for accuracy and affordability. Our friends just north of the Illinois border also have great customer service.
The setback of rear hub-based power meter is that your device is paired with one set of wheels. If you train and race on different wheels, you will need two devices.
It’s possible to purchase wheels already equipped with a PowerTap or to have a new wheel built around the PowerTap hub. Already have a great set of wheels? Talk with our mechanics about how they can lace the PowerTap into your existing wheel.
Crank Arm-Based Power Meters
Still relatively new to the scene, Stages came out with a crank arm-based device. The device basically replaces your non-driveside (or left) crank arm, meaning that it is only measuring half of your power and “uses an algorithm” (read: multiply by two) to measure your total power. Stages power meters work with both ANT+ and Bluetooth devices.
The greatest advantage to the Stages power meter when it bounded on the market back in 2012 was its affordability. Since its competition’s pricing has dropped following Stages introduction, there are more accurate devices available for comparable prices. That said, its ease of use is undeniable.
Pedal-Based Power Meters
The Garmin Vector is a pedal-based power meter. Capturing reading from both right and left pedals, the Vector offers more accurate readings when it comes to registering discrepancies between legs. This is useful information when trying to smooth out your pedal stroke.
The greatest limiting factor with the Vector is the pedal platform choice. If you don’t currently ride with Look-Keo or compatible pedals, you’ll have to get used to a new pedal/cleat setup.
Considering riding with power and don’t know where to start? Come in to Higher Gear to chat with our knowledgeable mechanics, who can help you determine the best power meter option for your needs and your budget.
For an extremely in-depth comparison – and a comparison chart – of power meter options, check out DC Rainmaker’s “Buyers’ Guide.”