Verve manufactures InfoCrank to the high standard required of a precision instrument.
By controlling all manufacturing processes, we set a standard of accuracy that’s not possible by adding a power meter to an existing crankset, The crank is a top-quality, conventional 2D cold forging.
The pockets are machined to a precision of five-100ths of a millimetre (0.05 mm).
The strain gauges are bonded into symmetrical pockets in the inner and outer faces of the crank. Variations between left and right cranks in a pair, or from pair to pair, are vanishingly small, amounting in no case to greater than a 1 watt difference as manufactured—eliminated in any case by factory calibration.
Our focus in manufacturing the InfoCrank is on accurate assembly of mechanical and electronic components into a precision load cell capable of reliable and stable performance even in a hostile operating environment.
Why do we say InfoCrank—an alloy crankset for a road bike—is a precision instrument? Because each crank, right and left, is designed expressly around a strain-gauge load cell.
A load cell is a transducer that converts a force into an electrical current, and is used for measuring instruments such as lab and industrial scales.
A single InfoCrank arm is so very accurate because the strain gauge measures only tangential force, or torque—the force the rider puts in that drives the bicycle forwards. The load cell design means that side, radial, and twisting loads that are exerted on the crank (but do not move the bike forward) are not measured.
Every load cell is individually calibrated and independently tested and externally certified. The certification tests proved an installed, operational InfoCrank had an average error of <0.2% in the zone where we ride most. The greatest error in 100 tests was 0.57%. No other power meter has achieved such high levels of accuracy.
A strain-based load cell’s accuracy is degraded by external temperature changes—a problem for cyclists who, as all-weather athletes, expect to be able to use their equipment in all conditions.
Temperature changes cause thermal expansion that can be confused with a load change and result in incorrect power readings, so power meters that use strain gauges must compensate for these errors.
InfoCrank overcomes these false readings by using the highest-quality strain gauges that are compensated for the thermal expansion of the aluminum crank. Additionally, the use of four strain gauges in each crankset in a full Wheatstone Bridge configuration inherently compensates for temperature, and makes the InfoCrank insensitive to temperature changes. The quality, match, and placement of the strain gauges with the alloy and the full Wheatstone Bridge configuration is the most accurate solution to temperature-corrupted readings.
- Left and Right power meter crankset
- Compact 110mm BCD spider
- Stiff M30 axle
- Weight 694 grams
- IPX7 waterproof
Occasionally, without notice, manufacturers change product design and/or specifications.