- By Craig Griffin & Eric Fletcher of WiredBike.com –
The history of powermeters outside of Saris’ Powertap and SRM has been one of over-blown promises, vaporware and generally compromised function and customer support. When asked to recommend a powermeter, never have I strayed from the big two. Time and again, start-up companies found that while the concept of a powermeter may be simple, executing a reliable, accurate and durable piece of precision electronics which will be exposed to heat, cold, high speed water exposure, dirt, grime and harsh impacts and vibrations is actually much harder and more expensive than it looks. Add in providing timely warranty, calibration and customer service, replacement parts and the related firmware and software updates (across various computer platforms no less) and the cycling powermeter game becomes down right tricky.
Into this treacherous arena comes the Quarq Cinqo powermeter. With an aggressive web based campaign and promises of an open-source Linux based ANT+ Sport head unit you could customize extensively, compatibility with the current cranksets with a removable spider you already have, and a price $1000 less than a new wireless SRM, data junkie cyclists sat up and took notice.
First The Bad News
Unfortunately, while Quarq has had some impressive successes (such as the Cervelo test team adoption of their powermeter), most of their promised compatibility is the two most dreaded words in the cycling industry “coming soon” (although “two weeks” is a close second). More disappointing is the lack of the much hyped Qrainum head unit which is still “under development”. Thus you are going to be stuck with a third party head unit, either the pricey Garmin 705 GPS computer ($649.00) or the iBike iAero right now.
Crank compatibility is a bit more limited than initially promised with compatibility with the Rotor Agilis, FSA Team Issue, Pinarello MOST, SRAM S900, Bontrager Race X Lite and the Truvativ Rouleur Carbon. As you can see the list is dominated by last generation cranksets for the most part, as newer models have replaced the SRAM, FSA and Truavtiv models used by Quarq. However, TT specialists, track racers and most importantly BB30 bike owners will be excited with future production run: the FSA Krono TT, Cannondale SI Hollowgram, Specialized S-Works Carbon, Lightning Carbon and FSA Carbon Pro Track cranksets are listed by Quarq.
How’s This Thing Work?
Power meters, in a simple definition, are measuring the amount of effort the rider is putting into moving the bike forward. There are a variety of methods for measuring this, with the most common using strain gauges to measure the flex of a metal component with a known deflection rate. The rider’s pedaling force causes minute flexing in the calibrated metal component. The strain gauge precisely measures the amount of this deflection, and calculates the torque based on the amount of deflection times the known deflection rate. Once you have a good torque number, that is multiplied by cadence to get the magic number: power in watts.
Power is measured by strain gauges built into the spider.
Different manufacturers put the strain gauges in different places. In a Powertap, it’s the rear axle. In an SRM, and now the Quarq, the strain gauges are applied to a custom set of spider arms within the crankset. In this location, the force applied to the crank arm causes the spider to flex ever so slightly. This deflection is measured by 10 gauges placed evenly around the spider- more measurement gauges than any other powermeter on the market today.
The Quarq also has an innovative method for communication with the head unit: wireless! This is one of the first wireless only crank based power meters on the market, and smartly uses the excellent and reliable ANT+ Sport wireless technology. Rather than trying to design and build a proprietary wireless technology, Quarq licensed the Ant+ system to give data transmission under all conditions. As a veteran of many flaky, fragile wireless products with short battery lives, I applauded the effort.
The question is: will it work? A powermeter is shoveling a good bit of data to the head unit at all times, more than just passing a notification that the wheel magnet passed by again. Reliability is crucial in powermeters. I’ve watched one of my PM’s fluctuate from 50 -1000 watts while coasting downhill before. Kinda makes the download anti-climactic after a 3 hour ride.
Out of the Box
Like SRM, Quarq installs their power meter unit on 3rd party cranksets, so in our unit, the stock FSA Team Issue spider was already removed, and the Quarq spider was pre-installed and ready to go. Chainrings were also installed and tightly assembled. As a thoughtful gesture, the stock spider was included in case we needed to switch the Quarq out and return the FSA to it factory state. On the scales, the Quarq retrofitted on the FSA crank came in at 780g w/o BB, so that was actually slightly less than what Quarq publishes for the unit (803g). Not bad!
The Quarq is simply repackaged in the FSA box – no fancy graphics here. Inside the box is the crankset with the powermeter installed, a short 8 page instruction sheet, and… 2 part epoxy?? Yep, there’s a mysterious 2 part putty included. You don’t see that often. Read on to find out about the putty, and the first new powermeter platform in years…
We anticipated the installation would have 2 basic phases. Phase I would be the physical installation, which appears to be pretty much like any other crankset. Phase II would be the software installation, which involves getting 2 products from different companies to play nice. Since there is no Quarq head unit (yet), your choices are the Garmin 705 GPS computer or the iBike Aero for compatible head units. We chose the Garmin 705 to pair up with the powermeter.
For now, the Quarq requires either a Garmin 705 GPS computer or the iBike iAero computer to process the data.
This Putty Ain’t Silly
As far as mechanical installation was concerned, it was no different than a typical crank installation. Except the putty. Yes, we had to read the directions. Turns out, the Quarq gives the user three powerful rare earth magnets to stack out from the chainstay. The requirement is that the magnets are 12mm or less from the crank. Compare that to the 1-2mm of an SRM, and you realize the whole new world of installation flexibility with the Quarq. Giant oversized carbon bottom bracket shells? No problem. How about a 54t chainring with a flared chainstay on a oversize aluminum frame? Plenty of room to adjust.
How about using some strong putty to place the stackable magents exactly where you want ‘em?
And that’s where the putty comes in. Rather than having the electronics pick up a moving magnet, Quarq has a magnet epoxied to the chainstay, and measures cadence off that. The instructions state that the putty is a temporary install – not a permanent attachment, but one to test different locations before using some other, more permanent method. Since we are lazy, we just used the putty for the test, and had no problems. Ultimately, some kind of trip to the hardware store would be required, for a sampler of tape and epoxy. One pleasant outcome of the installation process is no zip ties. None. A really nice, clean install all around.
Power meter set-up often is the time that tries a (wattage obsessed) racer’s soul. Many power meters can be absurdly fussy about how you set up and install it. This can be a real issue for wired SRM’s in particular given the small window in which they are happy with regard to sensor placement. The Pro trick has always been to chuck any supplied wimpy magnets and upgrade to a much more powerful rare earth magnet whenever possible. The fact that Quarq provides one in the box is great, the putty solution not so much. I am thinking tubular glue and a bit of electrical tape may be an option for riders looking to replace the stock putty on their bike.
Pairing the Quarq and the 705 was very easy- in a rare cycling industry pleasant surprise, but part of that was because we made sure we had the latest firmware for the Garmin before was started. This is critical. Earlier Garmin firmware versions did have issues so you must update your head unit’s firmware prior to pairing the two devices. Once our FSA crank based Cinqo was installed, the set-up and pairing was pleasingly quick. A trip through the Garmin menu, a few button pushes (the Cinqo booklet has screenshots – so its hard to mess up) and presto – the Garmin saw the Cinqo. And like a Bulldog with a bone, it held on tight, never losing lock on the powermeter even over rough gravel roads and under powerlines. That was impressive.
Riding/ Data/ Garmin-Quarq Use
The Cinqo-Garmin combination work similarly to an SRM set-up, with the major on-bike differences being the size of the Garmin headunit. I would love to see a smaller, touchscreen version that omits the GPS and other needless aspects for racers and integrates an SD slot for storage – how about 4 Gigs of replacable storage for $75? And a Bluetooth emitter for wireless data syncs. Bet you could sell a few of those. As for the Cinqo itself, it felt like any other FSA crankset – which is a good thing. The spider swap-a-roo does not seem to have any effect on the crank’s rigidity. Several 1000+ watt sprint intervals showed no adverse flex in the crank.
Data Analysis/Cycling Peaks
Downloading the data was straightforward on my Microsoft Vista equipped computer. Using the Garmin supplied mini-USB to USB cable I simply plugged in the computer, and Vista installed a few drivers and the Garmin showed up as a drive on my computer. No CD’s or downloads needed which is nice. In the Garmin directory is the helpfully named “data” folder. The file names have the full date included, so finding the ride you want is pretty easy. I tended to simply drag the file onto my desktop, then drag it into my copy of Cyclingpeak’s excellent power analysis software which then quickly imported the file. Note, this was another occasion that doing your updating first (in the case downloading the latest build of the CyclingPeaks code) clearly paid off. The data files I reviewed were clean, with no data drops and the wattage numbers were in the ranges I expected.
While I used the auto-zero procedure set-forth in the Cinqo documentation, you get no feedback from the Garmin when you do it so the concern that your unit is zeroed properly is always there. Compared with the superior zeroing process offered the dedicated head units of the SRM and Powertap power meters, this was an area where the Qranium’s “still under development” status let down the strong performance of the Cinqo crank.
While the all important consistency was there with the crank, sometimes the peak power numbers seemed a tad high and I wanted to check the offset to see if it was off or I was just having a good day. Being able to check the offset numbers directly like you can with an SRM head unit would help with that. Fortunately, on the post-ride data analysis all of the number wattage averages matched those I have seen with my SRM and Powertaps.
We came into this test with low expectations due to the previous failures of power meters outside the Big Two (Saris and SRM). Add in wireless technology, two different companies and an install process involving both putty and a rather skimpy pamphlet and I was worried I’d be spending time on various wattage forums debugging random glitches.
Instead, I was on my bike training hard. Including heaping helpings of Virginia’s bumpy and rutted gravel backroads (our version of Roubaix style pave) I threw everything I could at the Cinqo/Garmin 705 combination- and it simply worked. If you own either a Garmin 705 or an iBike Aero, and are interested in improving your training this is a slam dunk. For other buyers, the Quarq Cinqo powermeter at a price comparable to the Powertaps and over $1000 less than the new Wireless SRM’s is a very tempting bit of gear you should strongly consider before making your buying decision.
• Quarq Cinqo w/ FSA Team Issue Crank
• Get More Info: Quarq.us
Where to Get ‘Em
About the Author: Craig Griffin is a 15 year bike racer who loves training with power and has extensive experience with many different power meters and cyclometers. WiredBike.com sells a large variety of electronic training devices for cyclists, including bike computers, power meters, hrms and electronic trainers.
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