Foldable Bikes Party: 4iiii Precision Dura-Ace 9000 power meter review

Tuesday, 23 August 2016

4iiii Precision Dura-Ace 9000 power meter review

http://ift.tt/2bK0vcI

You can buy 4iiii Precision power meters in two ways: as a new left crank with the power meter installed, or, for less money, you can send the Canadian tech firm your left crank and they will install a meter and ship it back to you in a claimed 1-2 weeks.

I tested the already-installed 'Ride Ready' option on a Shimano Dura-Ace 9000 crank against two and three other meters simultaneously for 10 rides and found the accuracy to be good, considering the inherent limitations of a left-only meter. On two rides the ANT+ signal dropped out a number of times for 2-3 seconds, but on the whole I found the Precision to be a decent tool for the price.

Left-only and lightweight

4iiii claims its meter adds a mere 9g to the left crank arm. You can buy the meter on Shimano 105, Ultegra and Dura-Ace road arms, as well as XT and XTR mountain arms. We weighed our test 172.5mm crank to be 10g more than a stock Dura-Ace arm, also in 172.5. Whether 9 or 10g, the thing is so light you won't notice it.

Functionally it works similarly to the Stages left-only meter that preceded it on the market: it measures your wattage at the left crank and doubles that number for your total power, which it relays on either ANT+ or Bluetooth to any compatible cycling computer or smartphone.

So is this left-only power meter accurate? In my testing, I found the answer to be yes, mostly. I have found that for tempo efforts and above, my left/right balance is usually between 50/50 and 49/51. At easier, just-toodling-along paces, the left/right balance can vary more. Cycling coaches say this is the case for most people. For me, I'm not really concerned with exact wattage numbers when doing an easy ride or recovery between efforts; I am interest in accuracy when doing intervals. For this purpose, I found the 4iiii Precision to be a good training tool for the price.

Data comparison vs. PowerTap and others

Durability and compatibility

Also consider

Stages Dura-Ace power meter

When it launched, Stages was unique for being a left-side-only crank based meter. This design makes it more affordable, less complex and easier to fit. Power is measured with strain gauges factory-bonded to a left crank, doubled and then sent to a head unit via ANT+ to a computer or Bluetooth to a smartphone app. The new housing has addressed the water-seepage issue that plagued some of the initial units.

Read the full Stages Dura-Ace 9000 power meter review

Pioneer single- and dual-sided power meters

Pioneer offers a unique power meter configuration: the dual-sided meter can be split into two functional one-sided meters. Further, when used as a dual-sided meter, Pioneer can give you what the company calls force vector measurements, showing where and in what direction power is being applied at 12 points along the pedal stroke. More pertinent to the 4iiii Precision, Pioneer is selling its left-sided meter for US$629, with the option to upgrade to the dual-side down the road.

Pioneer drops prices to undercut Stages

You can read more at BikeRadar.com