The Bike List

First impressions: Power2max Rotor 3D Plus Power Meter €770

Tested by Nik Cook, tester for The Bike List

I've been procrastinating about getting a power meter for a few years now. I've been holding out for Garmin's Vector pedal system but, with their launch seemingly terminally delayed and concerns about a £1200+ piece of kit in such a vulnerable position on the bike, it hasn't happened. The cost and lack of bike to bike flexibility of crank systems such as SRM and Quarq was off-putting and, although Powertap's hub based system was more affordable, it left me with a choice of racing on training wheels or training on racing wheels. I'd be stuck then with training with heart rate but, looking for an edge to help me defend my age-group title at the World Long Course Duathlon Championships at Powerman Zofingen in September, thoughts of power came to my mind again.

To meet my requirements I needed to be able to easily switch the power meter from my road to my TT bike. Talking to power2max they assured me that with the Rotor 3D Plus crankset I had on my road bike and a bottom bracket adaptor on my TT bike, it'd be no more than a 10 minute job.

In the box for the €770 came the power meter, user replaceable battery and a specialist tool for removal of the Rotor lock-ring. The Rotor BSA30 bottom bracket I needed to also run the 3D Plus crankset on my TT bike added another €159 to the bill. I already owned a Garmin 800 and Garmin 310XT that would both talk to the power2max as it's ANT+ compatible.

As I run Rotor Aero chainrings, a small notch had to be cut out with a dremmel to accommodate it but this was easy enough to do. Removing Rotor 3D Plus cranksets is a breeze, even for a non-mechanically gifted individual like myself. Undo the lock-ring with a cassette tool and then a 8mm allen key does the rest. Next was removing the lock-ring with the specialist tool. This is held in place with 50NM of torque and a lot of lock-tight. You'll need a vice and a decent sized lever to attach to the tool. With this done, you just replace the existing spider with the power meter and job done. Put the battery in, you'll need a very small Philips head screwdriver, the LED will flash for 20 seconds and it'll pair to your head unit. Miss this window and you can pair up when you start turning the pedals which automatically turns the unit on.

The main niggle with the first generation power2max meters was poor temperature regulation but this has now been totally ironed out with the current models and they auto zero whenever you stop pedalling for more than 2 seconds. The unit will also estimate left/right power balance but it is only an estimate and the value of this data is questionable anyway. More importantly, using an accelerometer, you also get cadence without the need for an additional sensor.

Onto the road bike and, knowing my FTP (functional threshold power) from lab testing, I headed out for a fairly hilly 100 km /1300 m ride with an aim to maintain an NP (normalized power) for the ride of 280W. This translates to about 70% of my FTP and would be the sort of level I'd aim to ride the 150 km bike leg at Zofingen at. To achieve this I'd monitor 3 sec average power and try to stick on climbs to not more than 320w, flat 280-300, downhill 240-280w and coasting above 50kph.

Straight away everything worked seamlessly and I settled into the rhythm of riding with the power meter. Immediately I noticed that I had to throttle back on climbs and avoid my usual habit of powering over rises which would spike the power up to 600-700W. On flats the pace felt exactly right but I found I was pedalling longer and harder on downhill sections. On the whole the effort felt far more consistent than I normally ride and, as the ride went on, I found I was riding faster with what felt like far less effort. It almost felt like cheating and, for pacing long rides optimally, I realised I'd struck gold. I finished the ride in a best time and my legs felt noticeably less fatigued than they normally would.

The next test was swapping the power meter onto the TT bike and, as promised, it was a painless job that only took about 5 minutes. An interval workout consisting of 5 minutes at threshold followed by 2X20 at "sweet-spot", was so much more focussed using power rather than heart rate. There was none of the lag at the start of the effort, no easing due to cardiac drift as the session went on and no hiding place from the hard data in front of my nose. If the power meter made pacing long rides easier, it brought out its task master's whip for intervals.

For analysing my data I signed up for a free Training Peaks account and this gives my all the information I need. For hard training TSS (training stress score) is invaluable and, if you're prone to overtraining and not factoring in enough recovery, is another massive plus of using power.

First impressions after a few rides are that training with power is going to be the tool that'll take my riding to the next level. The power2max power meter lowers the price bar of crank based systems, works brilliantly and is far easier to switch from bike to bike than I thought it'd be. A power meter isn't a miracle fix for your cycling and you have to be willing to invest a bit of time learning to interpret the data to get the most out of it and you still obviously have to ride the kilometers.

I'll keep training with it through the summer to Powerman in September and report back with a final and comprehensive review then.

Related Reviews:

Long term test: Power2max Rotor 3D Plus Power Meter

First impressions: Garmin Vector Power Meter Pedals

Summary: Rotor Power (including 3D+ crankset) power meter

Garmin Edge 810 GPS Cycle Computer - Performance Bundle

At a glance

Verdict Affordable crank based power meter.

power2max says:


Start pedaling, and it works. This is how simple and realiable power measurement should be. We have done everything to make it that way:

  • Auto Zero: Every time you stop pedaling for 3 seconds or more your power2max "rezeros", making sure you always get precise data. No need to rezero manually
  • No cadence magnet needed: you don't need to install a cadence magnet on your bike. Your power2max calculates precisely using cadence using an accelerometer
  • Freedom to change chain rings: You can change chain rings at any time without having to worry about calibration. Whichever rings you use - your power2max will be accurate and precise
  • Battery change: when the time comes to change your power2max after 300 to 400 hours of use (6,000 to 12,000km) you can do it yourself in the comfort of your home. No need to send in the crank, no lost training time, and you save money, too.

Your new powermeter

Six man-years of development, 167 structural elements, ten of which are specific components, and more than 50 process steps... In principle, the performance measurement between the crank and the chainrings is nothing new. The use of strain gages is also state of the art. power2max applies this principle but additionally defines major characteristics on a complete new level.


Besides the opportunity of selecting between different crank makes, power2max offers a unique design with a high recognition value. Furthermore, you can choose among five different application colours to create your individual power2max.


power2max power meters deliver precise and reliable data under all conditions: whether it's hot or cold, wet or dry, you can rely on your power2max. Our power meters are waterproof, resisting even the strongest rain. The in-built temperature compensation mechanism ensures that your power2max stays accurate in changing weather.

Easy battery change

power2max uses a Swiss-made commercially available battery type: CR2450 by Renata. At the end of its service life after approximately 300 to 400 hours (6,000 to 12,000 km), you can easily change it. No dismantling, no dispatch, no downtime and favourable follow-up costs speak for power2max.


power2max power meters use the ANT+ standard to transmit data wirelessly to your bike computer. The ANT+ standard guarantees reliable transmission and offers a large number of bike computers to choose from.

Designed, engineered, and made in Germany

We manufacture our power meters in Germany. The advantage for you? Consistently high quality and a product that is reliable.

±2% Precision

Power2max power meters deliver state of the art data: our power meters achieve accuracy of ±2% or better including all environmental influences. We achieve this accuracy through our refined design and high quality manufacturing process.

Left-right balance

Your power2max power meter estimates the contribution of your left and right leg as your ride. This offers useful additional information for your training.

Note: Power right = downward pressure on the right plus upward pull on the left. Power left = downward pressure on the left and upward pull on the right

Starting at a price of €740

Some versions of power2max cost €740 (incl. 19% V.A.T, plus shipping expenses). If you already have specific compatible cranks and a bike computer, you will experience performance measurement by power2max at this price.

One name, plenty of variations

Square taper bottom brackets, Italian and BSA, BB30, BB86, PF30, BB90, Hollowtech II, MegaExo, GXP, external bearing shells, PressFit, pitch circles 110 and 130 mm, crank length 165 or 180 mm - power2max has a solution for many specific conditions. Even solutions for MTB triple and double are available.


This development of the Spanish manufacturer ROTOR is the result of increasing demands for BB30-compatible crank set and follows in your design to the highly successful 3D ROTOR. It is made from high-quality aluminium, CNC-milled only and has elaborate laser applications.

High stiffness combined with less weight (it is the lightest version in the ROTOR Family) is the outcome of the unique "Trinity Drilling System".

The ROTOR 3D Plus is compatible with BB30 bottom brackets (original BB30 or external bearing shells).

The ROTOR 3D Plus comes with a special tool for assembling of power2max.