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by Matt Wikstrom
February 18, 2015
TECH NEWS BROUGHT TO YOU BY BIKEEXCHANGE
The Type S is the second iteration for Power2Max’s crank-based power meter design. The new design offers greater compatibility and weighs a little less, plus it has been incorporated into a carbon Campagnolo crankset.
Power2Max is a German company with a background in the automotive industry. The company started developing power meters for cycling around 2008 and after testing different approaches, settled on a crank-based system. The company unveiled its first power meter at Eurobike in 2010 and started shipping their first production units by the end of the year. The company has grown steadily since then and now serves customers directly with online stores for Europe, Australia and New Zealand, South-East Asia, China, North America, South Africa, Japan and Israel.
From the outset, Power2Max concentrated on a versatile design for its power meter. Rather than concentrate on the entire crankset, they set about designing a spider that could be adapted to suit cranksets from a range of manufacturers (FSA, Rotor, SRAM, Bor, TA, Tune). Buyers are also free to purchase the spider on its own if they already have (or can supply) a set of compatible cranks.
Power2Max recently overhauled the original design of its spider (now referred to as the “Classic”) to yield the Type S power meter. The new design is a little lighter than the Classic design, changes the orientation of the battery, adds an LED, and is compatible with the new BB86 standards (ie BB86, BB386) and aero chainrings. Power2Max also added a carbon Campagnolo crankset to their catalogue as part of their sponsorship commitment to team Movistar.
Power2Max promises that the Type S power meter is “simple2use” because it has a built-in cadence sensor, an automatic zero function, and is compatible with any ANT+ enabled device. For this review, Power2Max Australia supplied a Campagnolo crankset fitted with the Type S power meter.
There is a lot of peripheral hardware associated with a crank-based power meter, and as a rule, none of it is provided with the cranks. So it goes for Power2Max: the price for the spider or cranks does not include chainrings, chainring bolts, bottom bracket, or a device to receive and record the power data transmitted by the spider.
Power2Max sells directly to the public using online sales outlets that are stocked with cranks and spiders as well as all of the peripheral hardware required for installation and operation of the power meter. Buyers are able to find all of the pieces they need from drop-down menus before heading to the checkout, including the specialised tools that are required to install the spider on compatible cranks.
As a guide to pricing for Australian residents, a Power2Max-equipped crankset starts at $1,499 (FSA Gossamer cranks) while the spider alone costs $1,299. Praxis chainrings (with chainring bolts) can be added for $179 while bottom brackets range in price $30-80, depending on the standard (eg. BSA versus BB30).
A Power2Max spider cannot be retro-fitted to an existing Campagnolo crankset so Campag users will have to pay for an entire Record-level crankset (which includes the axle and bearings) for $2,399. Campagnolo chainrings and bolts add another $229 to the purchase price.
There are, of course, a variety of crank lengths (170, 172.5, 175mm) on offer along with different chainring sizes (50/34, 52/36, 53/39). At present, all of Power2Max’s road spiders use a 5-bolt pattern so buyers will need to decide between compact (110mm BCD) and regular (130/135mm BCD) sizing (4-bolt spiders to suit Shimano and Campagnolo should be available in the next few months). There is also a choice of five stickers (white, black, red, blue, green) that can be applied to the spider to co-ordinate the cranks with the rest of the bike.
A pre-installed battery is included with every power meter that will serve 300-400 hours of use. According to Power2Max, there is a strict requirement for Renata-branded CR2450N coin battery, so it is probably prudent to add a spare when ordering a Power2Max power meter.
Like other crank-based power meters, Power2Max utilises strain gauges to measure the torque applied to the cranks. The strain gauges are situated within the spider and by combining torque with cadence, total power can be calculated. The balance between the left and ride legs can also be calculated from these measurements, but this only serves as an indirect measure of power output by each leg.
According to Power2Max, the strain gauges have an accuracy of ±0.1%, however losses in the system and environmental influences result in an overall error of ±2%. This places the Power2Max in the same category as Stages and Pioneer’s Gen 2 while Quarq ELSA RS (±1.5%) and SRM (±1%) offer greater accuracy.
An accelerometer is installed in the spider to measure cadence. Thus, there is no need for a magnet or external sensor to measure the revolution of the cranks. There is a risk that excessive vibrations will interfere with the accelerometer however it simplifies installation and operation of the power meter.
To further simplify operation of the power meter, Power2Max have programmed the device to re-zero itself every time the cranks stop turning for more than three seconds. Thus, there is no need for the user to bother with a manual re-zero before, after, or during a ride.
Power2Max uses active temperature compensation based on factory calibration of the spider using a climate-controlled chamber, similar to the ELSA RS. In practise, if there is a change in temperature from one auto-zero to the next, then the on-board software will compensate for the change.
All Power2Max power meters are designed, engineered and manufactured in Germany. In-house testing has established that the Type S power meter will operate in all temperatures from -40°C to 60°C. At the same time, Power2Max is confident the device will be unaffected by water though there is no formal waterproof rating.
Power2Max uses the ANT+ protocol to transmit data. Any ANT+ enabled device (eg. Garmin 510 or 810) should work with the cranks including an iPhone fitted with an ANT+ adaptor. For this review, I used an O-Synce Navi2Coach to collect and record data.
Power2Max’s Campagnolo crankset isn’t assigned to any groupset, but according to the company, it is a Record-level offering. Thus the cranks arms are hollow carbon with an Ultra-Torque axle. According to Power2Max, the Type S spider adds around 180g to the weight of the crankset (174g for a compact spider, 188g for a regular spider); in this instance, the cranks sent for review weighed 799g (including the axle, bearings, 52/36T chainrings and bolts) compared to 627g for a standard Record crankset. Thus the compact Type S spider added 172g to the weight of the cranks.
Installing the Power2Max Campagnolo crankset was a very simple matter with no special considerations when compared to a standard Campagnolo crankset. Since there is no need to install any sensors or magnets, the cranks are ready to transmit data immediately. All that is required is to turn on the ANT+ enabled device and search for the power meter—if you’re familiar with the functions of your chosen device, then this should only require a few moments. For the uninitiated, consult the device’s manual to be guided through the process.
Changing out the battery was also a reasonably simple affair. While it is possible to take care of this job while the cranks are on the bike, it is far easier to carry out after removing them. Two rubber plugs must be removed from the back of the spider followed by two tiny screws before the battery compartment can be opened. Once opened, the battery slides easily in and out of the compartment. A video of the process can be found at Power2Max.
The Power2Max power meter is extremely easy to use, all I had to do was turn on the Navi2Coach, wait for it to locate the GPS satellites and the power meter, then I was able to view and record my power output.
If you’re looking for World Tour endorsements, Movistar and Etixx-Quickstep are on Power2Max powermeters this season
The utility of the Type S power meter will largely depend on the recording device. In this instance, the Navi2Coach resembled a Garmin 510 with training pages that could be customised to display multiple fields including average power readings for different intervals, peak power output, maximum power, normalised power and left-right balance. Compared to a Garmin 510, the Navi2Coach was slow to locate GPS satellites but otherwise easy to use.
Power2Max leaves data analysis in the hands of the user. I don’t have any data that proves the accuracy or reliability of the Type S power meter, however my power values agreed with those obtained previously with Quarq’s ELSA RS.
Power2Max claims that its Type S power meter is “simple2use” and I agree. By abandoning the need for a cadence magnet and incorporating automatic calibration into the power meter, this device is well suited to any rider that just wants to measure their power output.
Price and accuracy appear to determine much of the appeal of any power meter. In this regard, Power2Max should have plenty of appeal for Campagnolo users since the only other choice for a crank-based power meter is made by SRM that offers half the error (±1%) but demands twice the price and must be returned to a service centre to replace the battery.