Verve Infocrank: beyond torque
Verve Infocrank is now available through Vault Cycle Services WA’s Cheapest prices, inquire here
“It is taken for granted that the time is precisely the same regardless of which watch/computer is measuring it and that weight is the same regardless of your altitude, temperature, or set of scales. Yet for some reason, coaches and reviewers don’t get it. “
Recently we managed to get a few words from Verve Cycling President Bryan Taylor around what makes the Verve InfoCrank unique in an ever flooded market of power meter devices. Bryan’s response is unrelenting and unchanging, much the same as his passion for precise accurate repeatable data.
Tangential Load is at the crux of Bryan’s stance around the validity of the InfoCrank power meter. This refers to force that generates power as the crank rotates or its equivalent torque. InfoCrank have not retro fitted strain gauges to the crank, but rather have created a crank set that augments the strain gauges measurement. By measuring tangential load InfoCrank removes most of the noise that causes inaccuracy. The noise associated with power meter data is subsequently discussed.
Axial load cause tension or compression of the crank arm such as when the cyclists places pressure downward on the pedal and tension/compression occurs, this force produces no power. Side load occurs when the rider leans the bike on its side during acceleration, this force produce no power. Pedal axis torque occurs when load is applied to the crank through a pedal with faulty pedal bearings. Crank axis torque refers to a twisting of the crank arm as the pedal/crank centre line is offset, again this should have no power output. Finally, side torque bends the crank arm toward/away from the frame at the bottom of the crank stroke and should not produce a power reading.
In order to offset the load associated with noise the placement of the strain gauges, devices that measure the degree of stress and strain on the crank arm, are of great importance. Placing the strain gauges on the crank arm along a plane responsible for measuring tangential torque only is part of the reason why the InfoCrank unit stands apart from other power meters. This load placement is part of the reason why calibration readings for the InfoCrank are low, like really low, measuring within 10units consistently. An extension of this finding is attributed to the cranks ability to only measure tangential load through the pedal stroke, thereby removing large amounts of error.
Importantly the InfoCrank measures consistently valid outputs. This is important at a practical level as many highly trained athletes can battle for months to see a 2% increase in critical power levels. If some of this variance is attributable to error then the 2% may not be entirely valid. Conversely for the general cyclist, who can generally adapt at greater rates, they may not be accessing an accurate account of how they are adapting over time and indeed could not make inferences against others with less stable power measuring units.
Valid power meters can also be used to test for more intricate measures such as Drag coefficient (CdA) of a cyclist. Generally the variability of measurement when testing a cyclists CdA is around 1%, however certain newer models of power meters on the market have seen this variability increase to 3-5%, thereby introducing a large degree of error to aerodynamic assessment. Stable, precise, reliable measures are the only future for a sport intent on attaining incremental gains in human performance.
Bryan rounded out by saying, ” I hope this is helpful to you and enables you to tell a good and correct story as well as sell many InfoCranks. Be assured this is the new standard.”
Verve Infocrank is now available at the Hall Cycling Store for WA’s Cheapest prices, inquire here
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