Power Meters

It has become a critical part of many triathletes’ training: if they can’t document their power output for the workout, many triathletes feel they haven’t really done any training. Being able to gauge your power output can be an invaluable addition to your training arsenal, allowing you to monitor your improvement and help you to pace yourself accordingly during workouts.

Nowadays many triathlon bikes will come with a power meter – last summer Cervélo announced that many of its high-end models would come with 4iiii units, while other companies also include power meters from either SRAM or Shimano as part of their component packages.

If you’re looking to add a power meter to your set up after the fact, the advantage of a pedal-based system, such as Garmin’s Vector 3 (below), is that you can easily move the pedals to another bike, so you won’t have to purchase multiple power meters if you have a few bikes.

For those looking to add power to their training on a budget can save money with a one-sided based system. You’ll still get relatively accurate power data, but what you’ll be missing are the cycling dynamic measurements, like the balance between your left and right legs.

With all that in mind, here are a few options:

4iiii Precision Powermeter

$400 Accurate to one per cent, you can either buy ride-ready or factory installed 4iiii powermeters. The left-side precision powermeter for the SRAM Red 22 crank is installed by the folks at 4iiii – after you order it, the 4iiii team send you a prepaid FedEx return label. Once they have the crank it takes about seven to 10 days to attach the powermeter pod to your crank, at which point it is sent back to you.

What you get back is a unit that is both Ant+ and Bluetooth compatible, and that measures your power output through 4iiii’s patented 3D power measurement system in the crank with a three-year warranty. The waterproof pod weighs just nine grams and offers over 100 hours of riding time with a standard C2032 battery.

Garmin Vector 3

$1,300 While the Vector 3 is available as a single-pedal system ($780), going with the dual-sensing pair of pedals adds left/right balance and other cycling dynamics to the total power and cadence data you can get. Weighing just 316 g, the Vector 3 installs like any other pedal, so you can quickly transfer it between bikes. This latest version has a sleek design that provides greater cornering clearance. Using Ant+ or Bluetooth, you can easily connect the Vector 3 to Garmin or other computers and watches to be able to see all of your data. Measurement is done through the spindle and is accurate to one per cent. The replaceable batteries provide up to 120 hours of battery life.

Shimano Dura-Ace R9100P

$2,130 You’ll find the Dura-Ace power meter specced on many high-end bikes, which makes sense since you’re getting the benefits of Shimano’s lightest, stiffest crank coupled with dual-sided power measurement and a whopping 300 hours of rechargeable battery life. Shimano thoroughly tested this system for two years before it became available, so you can be confident it will get the job done.

The waterproof Dura-Ace power meter is both Bluetooth and Ant+ compatible and accurate to two per cent, and uses software that compensates the measurements at the strain gauges automatically to various temperatures. You do need to place a magnet on your frame to get cadence information, but since this crank will likely come with your bike, that’s probably going to be taken care of for you.—KM