FAQs

Crank spider-based power measurement was invented by SRM (Schoberer Rad Messtechnik GmbH) in the 1980s and has remained state of the art up until the present day. The principle of crank spider-based power measurement makes it possible to simultaneously and completely determine the power introduced by both legs. As a result, this form of power measurement – when compared to one-sided measurement systems with which only the power from one leg is measured – offers far more precise and reliable power values.

Four strain gauges are installed in the power2max Type S power meter. In the NG and NGeco power meter models, two strain gauges each are placed in a particular configuration in order to receive an even more exact measurement.

power2max Type S and NGeco power meters guarantee a precision of +/-2% when considering all exterior influences; the precision of our NG power meters is at +/-1%. power2max NG power meters are calibrated with a certified torque sensor that is verifiably accurate to 0.1%.

Shifts in temperature while using power2max power meters only have a minimal influence on the precision of the transmitted power values and are already included in the precision values of +/- 1% and +/- 2%. Our design allows for an excellent temperature compensation (TC); in the case of the NG power meter’s TC+, it is also actively corrected.

Yes, power2max power meters are waterproof. Rain, snow, mud and water do not influence the power2max’s function.

The power values that you see on your bike computer are approximately two seconds old and are updated every second.

power2max power meters are calibrated at the factory. A calibration by the user is then no longer necessary.

Torque is a physical value that can accelerate or decelerate the rotation of a body, or can warp or bend a body. Your legs create a power on the pedals that is turned into torque by the cranks.

The zero point is the value that the power meter measures when you are not pedaling, i.e. when there is no torque present.

Slope describes how much the measurement changes with increasing torque.

You can replace the battery in your power2max Type S or NGeco power meter on your own. It is not necessary to recalibrate after changing the battery. An instructional video for replacing your battery in a Type S can be found here:

Replacing a battery in a NGeco power meter is even easier; you just have to remove the battery cover and replace the battery. Make sure that the battery cap is correctly in place after the replacement.

Our NG power meter is equipped with an internal battery and a USB port. You can charge the battery with a USB power cord (USB 2.0 and later), a USB port of a computer or laptop, or with a power pack, among others.

The internal battery of the NG power meter lasts for about 150 hours of active use. The battery in your Type S or NGeco power meter lasts about 300 to 400 hours.

Yes, you can change the chainrings on a power2max power meter on your own. It is not necessary to recalibrate the sensor after changing chainrings.

The power2max Type S, NG and NGeco power meters are compatible with all ANT+ bike computers with a PWR profile (power only). The performance data are transmitted from the power meter to your bike computer with the ANT+ radio protocol. In addition, the NG and NGeco power meter can also be used with Bluetooth compatible bike computers.

You can find everything you need to know here: https://www.thisisant.com/consumer/ant-101/what-is-ant/

Before going out for a ride, it is not necessary to manually “zero” a power2max. The zero point is automatically renewed by the power2max when you stop pedaling (at least two seconds).

A manual zeroing before going for a ride or training is only required for the power2max track power meter. It does not have the so-called “automatic zeroing function”.

The NG determines the following data: watts, cadence, left/right balance, pedal smoothness (fluid pedal stroke) (only ANT+) and torque (only BLE). The NGeco power meters can determine the same data after an upgrade.

In the case of modular or two-part cranksets, you can separate the right crank from the spider where the chainrings are installed.

Shimano does not offer any modular cranksets for road bikes; this is why we recommend a switch to a modular, power meter-compatible crankset with a 24mm axle such as:

power2max NG Road with Rotor ALDHU 24 crankset

power2max NGeco Road with Rotor ALDHU 24 crankset

With our NG and NGeco power meters, you have the possibility to continue using your four-arm Shimano chainrings if you select the 110mm 4-S option.

To check the compatibility, look here.

If you are unsure which power2max power meter is compatible with your bike, then we recommend you contact the power2max Support Team.

For frames with BB386EVO or BB86 bottom brackets, you should definitely check the outer diameter of the bottom bracket.

It should not be wider than 53 mm (power2max Classic), 57mm (power2max Type S) or 59mm for NG and NGeco.

The power2max NG and NGeco power meters for FSA BB386EVO cranksets are compatible with all BB386EVO and BB86 frames. The compatibility of other power2max models should be checked before purchase and discussed with the power2max Support Team. For reasons having to do with specific elements of the construction, the Type S SRAM is not compatible with BB86 and BB386EVO frames.

The power2max Type S MTB Double models with two chainrings (bold circle diameter 110mm) are compatible with Q-rings; the power2max Type S MTB Single models (bold circle diameter 104mm) are not.

It is absolutely necessary to observe the torque values specified by the manufacturers when installing the power meter, crank and chainrings – only then can damage to the power meter or an unwanted detachment of various parts be prevented. The torque values have no importance in respect to the precision of your power2max.

You can find installation videos on YouTube: e.g.

You need the following tools to install your power2max:

Only for Type S: Phillips screwdriver PH1 (to open/close the battery case)

Allen key or Torx key (to install the chainrings)

Special installation tool (for all power2max models for cranksets with a lock ring such as Rotor, Cannondale, Specialized, FSA BB386EVO and Campagnolo)

Torx key (for all power2max models with cranksets with a screw lock such as FSA Gossamer and K-Force Light MegaExo, Sram S900, Force22, Rival 22)

All power2max power meters for cranksets with a lock ring, such as Rotor, Cannondale, Specialized, FSA BB386EVO, Campagnolo, require the special installation tool (specifically manufactured for these models) in order to mount the power meter on the right crank arm.

power2max recommends using Loctite 243.

The O-ring for the battery compartment is installed last when operating the power meter.

Open battery compartment

Insert battery

Close battery compartment and tighten the screws to the required torque value of 0,15Nm (carefully with two fingers)

Pull the O-ring over the battery cover and place it in the groove between the battery cover and the power meter.

It is not possible to install the O-ring before closing the battery compartment!

Replacement parts such as O-rings, battery covers and screws can be bought from the power2max online shop.

For road bikes there are two options:

Shimano chainrings:

• If you want to continue using your Shimano chainrings you can choose the 110 4-S version of our powermeters.

New chainrings:

• If you want to use new chainrings you have to choose the BCD (bolt circle diameter) of your chainrings according to the BCD of your powermeter (110mm or 130mm)
• For BCD 130mm you can use our PraxisWorks 53/39 chainrings which weigh 162g
• For BCD 110mm you can use the following PraxisWorks chainrings
  • 52/36 = 155g
  • 50/34 = 134g
  • 46/36 = 142g

A precise test is only possible under laboratory conditions; however, if you would like to have an orientation, then we recommend the “hill test”.

You need:

• your precise system weight (please stand on a scale in your cycling clothes with shoes, helmet, all accessories that you have in your jersey pockets and your bike);
• a climb / hill of at least 1000m and steeper than 5% (the longer and steeper the hill is, the better);
• your precise elevation gain over this distance.

Use your bike computer to check the lap time you require to complete the climb.

Evaluation here: https://www.broleur.com/hill-climb-calculator/

If your result at the website and the value of your power2max do not vary more than 10 watts, then the precision of +/-2 % has been confirmed.

(Variations up to 10 watts can be the result of imprecisions of the initial values)

In case the result at the website differs more than 10 watts to your power2max values, please contact the power2max Support Team.

You can also see how the hill test works in this video:

Comparing watt levels from different systems is not a valid approach to determine whether the “values are right or wrong”. Your power2max is a calibrated sensor. In contrast, indoor trainers create power without measurement; some models may measure watts/power, but with a different precision. In our experience, these values vary strongly in the display.

Even the power values of a Cyclus 2 ergometer, which is deemed to be a very professional and precise ergometer, can differ from the values of your power2max. You can test if your power2max measures precisely by taking the hill test.

Before going on a ride, turn the crank once to ensure that your power2max is no longer in sleep mode.

Please check if the battery indicator light (LED) is shining red. If it is shining red, the battery of your power2max is empty and needs to be replaced.

Enter into the menu of your bike computer and search for your power meter again. Please follow your bike computer’s instructions.

Contact the power2max Support Team .

For all service issues, we request that you contact the power2max Support Team.

We expressly advise that you not use a high-pressure washer or steam jet for cleaning. The power2max Support Team recommends cleaning with warm soapy water.

Shipping costs that differ and are higher can occur if your delivery address is in a difficult to reach area or so-called outer area; additional costs are thus calculated for shipping your order.

You will receive your order within 14 days.

Changes in orders can only be made in urgent exceptions and only before payment has occurred.

In Europe you can pay by bank transfer, by credit card or with PayPal.

The payment information will be sent to you per e-mail with your order confirmation.

The link to pay by PayPal will be sent to you per e-mail with your order confirmation.

Please check the settings of your PayPal account and contact the power2max Support Team.

The power2max Support Team recommends Golden Cheetah or WKO+ for a local analysis on your computer.

There is plenty of literature on the subject of power measurement. To begin with the subject of power measurement, we recommend “Training and Racing with a Power Meter” by Hunter Allen. In addition, you can also find test reports, training tips and various articles on power measurement in cycling and triathlons in various blogs, e.g. those by DC Rainmaker, Hunter Allen, Joe Friel or Alex Cycle Blog.

Hunter Allen says, „give your heart rate meaning by measuring power”. In short, it doesn’t make any sense to just train according to power levels or heart rates. Your power levels show you how strongly you actually turn the pedals; your heart rate shows you how much effort you expend to do so (how fast your heart beats). In order to improve your performance on the bike, it is recommended to always include both values in training analysis and planning.

Average power (AP) is the average power you produce during a defined period of time, e.g. a training session.

Normalized power (NP) is an algorithmically calculated value of your power (in watts) during a defined period of time. The algorithm includes the parts of constant power output and variable or irregular power output during a (training) session in the calculation of the power output. The result – the normalized power (NP) – is an attempt to represent the physiological effort or the level of effort to reach the power in watts. For example, if you ride with constant power on an ergometer, then your normalized power is equal to your average power. If the power values vary strongly, then NP and AP also differ greatly.

Functional Threshold Power (FTP) is the most power you can exert in watts on a bicycle for an hour. The FTP is used in planning training in order to define your various training power levels.

The individual anaerobic threshold (AT) is a physiological value that describes the intensity level at which lactate production and lactate breakdown take place at the same level. The AT and FTP are not the same values, but experience indicates that they tend to lie close to one another.

It is a good idea to invest in professional performance diagnostics before training with a power meter for the first time, since diagnostics can give you an insight into your current condition and your training can then be suited to meet your specific needs.

However, performance diagnostics are not a necessity or requirement to start training with a power meter.

There are numerous approaches to determining your FTP (Functional Threshold Power). The most reliable method to find out what your maximal average power for 60 minutes? Actually, ride exactly 60 minutes without stopping.

A quicker method is, for example:

10 – 15 minutes easy warm-up

5 minutes maximum effort

5 minutes easy pedaling

20 minutes maximum effort

20 minutes easy warm-down

FTP = AP 20 min (average power of the 20-minute interval) – 5%

A power2max power meter is the right training partner for you if you would like to improve your performance on the bike with targeted training plans;

• want to work on your strengths and weaknesses;
• would like to have an indicator for the “right speed”;
• need motivation for tougher training or if you need protection from training too hard;
• are training for a specific goal and want to be optimally fit for the event;
• would like to analyze your training or race data and share data with a trainer;
• would like to improve your bike position or aerodynamics;
• want to actively regulate your energy intake.