FSA Powerbox Alloy Features
•Spider-based power sensors provide total power output measuremt
•Cold forged AL6061/T6 aluminum crank arms
•BB386EVO 30mm AL 7050 alloy spindle fits every frame
•AL7075 100% CNC chainrings
•Fits Shimano and SRAM 10-11 speed systems
Road.CC Review FSA Powerbox Alloy Chainset
Overall Score: 4.5/5
Verdict: Accurate and reliable power meter at a very competitive price.
FSA has jumped into the power meter market by partnering with German company Power2Max to produce a crank-based power meter. Coming in at £599.95, the PowerBox Alloy Chainset is very attractively priced and is backed up by consistent and reliable performance.
The two companies have worked together in the past, but since the launch of its WE groupset FSA has stepped up its offering in the hugely competitive power meter market. PowerBox is available in two versions, either based on a Gossamer aluminium crankset, as tested here, or a K-Force carbon fibre option for £1,199.95. The prices include the aluminium chainrings, with a choice of ratios available.
FSA is using Power2Max's Type-S power meter, not its latest offering, but it's a power meter that has been proven in professional races over the years with several WorldTour teams, so you know it is built to last and accurate enough for the pros.
It's powered by a CR2450 coin-style battery hidden under a large rubber cover on the spider. Battery life is claimed to be good for 400 hours or 12,000km – I've not run close to that yet.
The battery is easy to replace: just flip that rubber cover, pop the battery out and replace it, and you're good to go. Any concerns it might not be adequately protected from the elements proved unfounded during testing in torrential rain and under the hosepipe when washing the bike down after mucky rides.
The crankset is made with 6061 aluminium, 7075 aluminium CNC-machined chainrings and a BB386EVO 30mm axle. The BB386EVO 30mm axle could potentially limit compatibility in some instances, but there are suitable bottom brackets and adapters available to provide installation for most bike frames. The aluminium version is available with 170, 172.5 and 175mm crank lengths, the carbon version increases the range, from 165 to 180mm.
I've been testing the new PowerBox for the last couple of months, a period of time that has allowed me to put the power meter through its paces in all sorts of conditions and long enough to uncover any hidden gremlins. I can report that there have been no issues at all, in fact performance has been flawless. I'm very impressed.
The PowerBox has delivered consistent power measurement at all times. The claimed +/-2% accuracy precision appears on the money during comparative testing with other power meters (a Wahoo Kickr and PowerTap P1 pedals) with no random spikes or anomalies to report.
It has worked consistently through large temperature fluctuations, the power meter compensating for any changes and preventing any drift in accuracy. Connectivity has been just fine via the ANT+ wireless protocol – Bluetooth Smart is going to be added as an update later this year, which increases the range of compatible devices.
Installation was a cinch. The cranks and chainrings are supplied preassembled so it's simply a case of removing the old crankset and sliding the PowerBox into place. Within a few minutes, it was paired with my Garmin Edge and ready to ride.
Okay, so it's not quite as easy as fitting one of the growing number of single-sided or pedal-based power meters, and swapping between bikes is obviously a drawback of a crank-based power meter, but if you only want or need power measuring on one bike, it's not a problem.
There's never a need to calibrate; the PowerBox has an Auto Zero function so you don't have to manually zero offset it before a ride, and it does this every time you stop pedalling for three seconds. The power meter goes to sleep when not in use and wakes up within a couple of pedal revolutions. You can also change the chainrings without affecting the calibration. An integrated accelerometer provides cadence data so no attaching magnets needed.
FSA makes excellent chainrings and they presented no issues on the SRAM Red-equipped bike I used for testing the PowerBox. The 7075 aluminium chainrings, compatible with 10 and 11-speed Shimano and SRAM groupsets and 10-speed Campagnolo, provided excellent shift quality – smooth and precise at all times. As well as the compact 50/34t tested here, FSA offers 53/39 and 52/36 options, using the same 110mm BCD (bolt circle diameter).
Any issues? None whatsoever. Performance was superb. Being critical, the PowerBox in this aluminium guise is no featherweight: the driveside crank is 669g. The carbon PowerBox drops that weight down to 585g but it's nearly double the price, so unless you're a weight weenie I'd stick with the alloy version.
But when it comes to price, the PowerBox has its rivals licked. An SRM is going to set you back £1,800, Pioneer's Dual Leg power meter is £1,100 and the Verve Infocrank is £1,149. The Quarq DZero 11R comes close at £693 but that doesn't include chainrings. So £600 for the power meter and chainrings represents a good buy. And a bit of shopping around reveals it can be had for less.
All things considered, the FSA PowerBox is a highly impressive power meter, and the price, performance and reliability make it extremely easy to recommend.
Accurate and reliable power meter at a very competitive price.
Review by Road.cc, David Arthur June 4 2017