power2max is less expensive than other products. What quality can I expect?
Exceptional quality is our top priority and we don’t compromise in this regard. We offer you exceptional features at a very attractive price:
- Precision of ±2% or better
- Waterproof construction that guarantees all-weather reliability
- User replaceable battery – no need to send in the unit
- Ability to change the chain rings without having to recalibrate the unit
- Left – right splitting and installation without the need for a cadence magnet
- Active temperature compensation keeps the sensor precise even when the temperature changes quickly
- Uses the popular and reliable ANT+ transmission standard that is compatible with a wide range of bike computers
- Attractive design that is easily recognized
How long is the warranty for power2max?
power2max power meters carry a 2 year warranty from date of purchase.
2. Functioning and quality
How does power2max work?
Our power meters work in the same manner as other crank-based systems on the market. Power2max replaces the spider between the crank arm and chain rings with a unit that measures torque, and thus power. The power2max spider uses strain gauges to measure torque and transmits data wirelessly via ANT+.
How accurate is power2max?
We calibrate our power meters with a torque sensor that has an accuracy of ±0.1%. We achieve precision of ±2% or better including all ?parasitic? environmental influences.
Which values does power2max measure?
power2max measures power and cadence and transmits the values to ANT+ compatible head units.
How "old" are the power values I see on the screen?
The values are about 2 seconds old and are updated every second.
How can I calibrate my power2max myself?
There are two important values for the precision of crank-based power meters: zero-offset and slope. The zero-offset is the value that the power meter reports when there is no torque, i.e. when you are not pedaling and there is no tension on the chain. The slope indicates how much the measured value changes as torque increases.
power2max power meters automatically update the zero offset when you stop pedaling. Anytime you stop pedaling long enough (approximately 3 seconds or more) power2max updates the zero offset. You can also update the zero offset manually through a compatible head unit.
The slope does not need to be calibrated by the user. Other systems require calibration in two cases:
1. When you change chain rings
2. Due to aging of the materials of the power meter
power2max power meters have been designed in such a way that you can change chain rings without having to recalibrate the unit. Calibration remains unaffected by the choice of chain rings and chain bolt torque. We do however, recommend tightening chain bolts to the prescribed torque.
Furthermore we have constructed power2max power meters in a way that aging of materials is not an issue. You don?t have to worry about the calibration of your power2max.
If you want to verify the calibration of your power meter anyway you can send it in for calibration. However, we don?t see this as necessary.
Another possibility is to conduct a dynamic calibration yourself: you can compare the values from your power2max with a CYCLUS 2 professional ergometer. This ergometer also has a known precision of ±2%. Please contact us for a comparison test protocol if you wish to conduct this test.
Do I need to recalibrate my power2max if I change the crank or chain rings?
Changing cranks or chain rings does not affect calibration. You can also use oval chain rings (e.g., Rotor Q-Rings, Osymetric, etc). Please note: compact (110 mm) aero chain rings (such as Rotor aero Q Rings) are not compatible with power2max.
3. Installation and use
Are mountain bike models available?
We have four different crank models available for mountain bikes. All models are available in double and triple variants:
- ROR XC666
- Rotor 3D, 3D Plus, and 3D F
Is there a triple variant for road bikes?
It is possible to build up a power2max as a triple crank set. However, this is only possible if you use a square taper bottom bracket since it allows you to use a longer axle. You need the following:
- power2max power meter with 130mm BCD, for square taper
- The right crank (TA Carmina or Vega)
- An adapter for the small chain ring (see here))
You can install the following chain ring sizes:
- Small ring: 24 to 30 teeth
- Medium ring: 38 to 42 teeth
- Large ring: 46 to 56 teeth
When mounting the crank set one has to ensure that there is sufficient space between the small chain ring and the frame. Compared to other triple cranks the chain line is 1.75mm closer to the frame.
What kind of bike computer do you need?
You need an ANT+ compatible computer that reads power data. In our shop we have the Navi2Coach from O-Synce. Other models that meet this criterion are the Garmin Edge 500/510 and 800/810, Bontrager Node 1 and 2, and O-Synce Macro X. See also under www.thisisant.com and check for the function PWR.
Can I clean the sensor with a pressure washer?
Cleaning with a pressure washer or steam cleaner is not recommended. We generally recommend cleaning with warm soapy water.
What kind of software can I use to analyze my data?
There is a large number of solutions available on the market. You can use the software that comes with your bike computer (e.g., Navi2Coach), you can use a third party desktop software (e.g., WKO+, GoldenCheetah), or an online program (e.g., www.trainingpeaks.com).
Can I also view torque?
We directly transmit the power value and not the torque, since the torque value varies across the rotation of a crank.
Can I use power2max with 11-speed drive trains?
Yes, power2max power meters are compatible with 11-speed drive trains. All you need are 11-speed compatible chain rings for your power2max.
Please note that original Campagnolo chain rings are not compatible with power2max power meters. The bolt chain diameters are 135mm (standard) and 113m (compact) and hence don?t fit with 130mm and 110mm sensors. Please choose 130 or 110 mm chain rings that are specified for 11-speed drive trains (e.g., Stronglight, FSA, or TA).
Does power2max need a magnet to determine cadence?
power2max power meters don?t need a magnet to calculate cadence as the power mater calculates it internally.
The compatibility of your power2max with the frame depends primarily on your choice of crank. If your frame has a BSA68, BSA73, ITA70, square-taper, BB30, or PF30 bottom bracket housing there are no constraints. On certain frames with BB90 or BB86 bottom brackets the sensor may collide with the frame. Please check the compatibility page to see how you can test this.
Do you have power meters for Cannondale SI and Specialized S-Works Fact Carbon cranks?
Solutions for these cranks are not planned.
Can I use my existing crank?
You can use your existing crank if it has a removable crank spider and if we have a compatible sensor for it. For road bikes we have sensors for the following cranks:
- BOR RR688
- Rotor 3D, 3D Plus, and 3D F
- SRAM S900 until 2009
- TA Carmina, TA Vega
- Tune Smart Foot
For mountain bikes we have the following models:
- ROR XC666
- Rotor 3D, 3D Plus, and 3D F
4. Delivery and price
What do I get?
Please see the product pages for details on what is included with each power meter model. All our mountain bike power meters are delivered with chain rings.
Which colours can I choose from?
You have the choice between 5 colours: power2max-green, red, yellow, white, and blue. You can also mount your power2max without the coloured ring.
Can I also order my power2max without a crank?
Yes, that is possible if you have a compatible crank (BOR RR688, Lightning, Rotor 3D, 3D Plus, and3D F, SRAM S900 up to 2009, TA Carmina, TA Vega, or Tune Smart Foot). You will have to mount the power meter. The process is very well explained in the manual that comes with your power2max. The steps are:
1. Mount the chain rings on your power2max
2. Mount your power2max on the crank
3. Install the crank on your bike
4. Install the battery and pair the power meter with your bike computer
5. Start riding and enjoy your power2max!
I would like to be come dealer. Could you please send me information?
We deliver directly to our clients and currently don?t plan to distribute via dealers. Thank you for your understanding.