Jul 30, 2012
What is a Power2Max?
Power2Max appeared on the market in early 2011 selling a crank based power meter, very similar in concept to the Cinqo and SRM. They arrived on the scene with none of the usual prolonged anticipation and endless waiting, with most people only becoming aware of their existence a relatively short period of time before the product became available. Their pricing is very good compared to a Cinqo or SRM, and I was particularly interested in the fact that the Power2Max doesn’t use a magnet / reed switch combination, as I had seen issues related to this with my first SRM
As soon as it became clear that some users were indeed receiving their Power2Max power meters, and they seemed to be working okay, I was willing to order one seeing as I had sold my SRM wireless at the end of last season in order to raise some funds to buy a house! I had used two PowerTaps and three SRMs (2 wired, 1 wireless) prior to using the Power2Max. I have never used a Cinqo, so will not be able to draw any comparisons with that.
Buying a Power2Max
The Power2Max website is http://www.power2max.de/ I ordered a Rotor 3D 130mm version for my first Power2Max, choosing the option to include the crank and tool. The tool is needed to assemble and disassemble the spider and drive-side crank arm. For about another £100, I could’ve opted for the titanium spindled 3D+, but being skeptical about the item, I went for one of the cheapest options available. I close the eye-catching fluo green decals as I thought they complemented the black chainset and my bright blue team issue Colnago M10 superbly.
My order was placed on 04th March, whilst on the final day of my training camp with RUTT, and I received an email from Power2Max confirming my order and requesting payment of £842 including shipping to the UK by bank transfer- the figure was actually in Euros, but after conversion, this is the figure it equated to, which was still about £300 less than the money I received from the sale of my 3 year old Dura Ace SRMs. This method of payment may surprise some customers, but it is apparently common practice in Germany. I was unsure about the promptness of payment, but paid almost immediately so that I could get the P2M asap (the start of the season was looming).The email also gave an expected delivery timescale of week 15. It does seem a bit strange placing an order, paying all the money and not receiving anything, by rest assured the goods did turn up about 5 days earlier than planned via courier.
What is in the box
Included in the box is:
The Power2Max spider, which is on its own in a separate foam padded box
Disassembled Rotor 3D crankset including the original Rotor spider
Rotor tool needed to attach the spider to the crank arm
The Power2Max user manual, first half in German, second half translated to English. The English translation is of a high standard
Rotor 3D crankset user guide
Note that chainrings are not included.
The original Rotor spider weighs 58g. The Power2Max spider weighs 264g, so the extra weight is 206g (130mm version).
The Power2Max appears to essentially work fine for many people’s needs, and hence is good value for money for anyone who wants a crank based power meter with the freedom to use different wheels. Although I have used higher end powermeters in the past, I am more than happy with my P2M, more bang for the buck as they say. I have no aspirations to change it, although I might look out for a second hand set of 3D+ arms to shave a little bit of weight off next season’s race bike. The data it has given is not dissimilar to that which came from the SRM last year- I’m using the same Garmin Edge 500 head unit. I haven’t overnight gained 100W in power or anything. There are occasionally erroneous data figures, but not as bad as used to be produced by my powertap wired. The data figures shown on the head unit don’t always reflect what is shown on the graphs after downloading, but I can live with accepting that I only produced 1300W and not 2000W in the final sprint! I would have no hesitancy recommending a P2M to anyone who hasn’t quite got the £ for an SRM or Cinqo, but wants the flexibility of being able to use a multitude of wheelsets (at the time of writing this, I have 4 different wheelsets that I use on my M10!).
Outputs zero power when the rider isn’t outputting power when stationary, like a PowerTap, rather than leaving gaps in the recorded power data like a Cinqo.
The cheapest crank based power meter.
Maintains 1 second updates to power and cadence right down to 20rpm.
Available with many different crank options.
Not using reed switches may prove better for avoiding the power / cadence spikes that can occur with a Cinqo.
Doesn’t need anything such as a magnet attaching to the bike frame.
Appears to give a low level of micro-variation in power data.
Accuracy appears to be good when properly zeroed.
Auto-zero feature when freewheeling will keep it properly zeroed for many people in normal outdoor riding
Faster response than a Cinqo at the start of a TT.
Zero offset of many units appears to shift more than that of a Cinqo, which will cause it to no longer be properly zeroed if used in a situation where an auto-zero will not occur, and the user cannot manually zero it.
Heavy, adding 206g of weight. According to this page Cycle Power Meters The Cinqo adds 124g of weight.
Quite bulky compared to a Cinqo.
Cadence lags 3 seconds behind speed at normal riding speed & cadence, this can be worked around using a 3rd party cadence sensor, which a Garmin will use in preference to the Power2Max’s cadence data)
Auto-zero cannot be disabled.
Number returned when performing a manual zero does not give sufficient resolution for accurate checking of calibration.
User changing of calibration (setting the slope) is not possible.