BIKE FIT PHASE FOUR: Adaptation of Laboratory Grade Power Crank System

New innovations in crank/pedal torque analysis has provided ATA Cycle’s FitLab with laboratory grade, propriety power cranks that provide us the ability to observe left and right leg pedaling parameters, both separately and continuously with real-time analytics and protocols.

The benefit of FitLab’s power crank system, is cyclist can be preliminarily tested for deviations in right and left leg power output, vertical landing patterns in relationship to pedal axis and cleat offset, as well as detailed on-screen CAD outcome data relative to both “power phase” and “recovery phase” during each pedal rotation.

Specifically, FitLab’s power crank system can measure the following data:


Each crank arm independently measures:

In turn, this data is transmitted in realtime, via BLUETOOTH to a PC.

Knowing the CRANK LENGTH and the PEDALING SPEED, the software derives the pedaling POWER and EFFICIENCY values for each crank, and their TOTAL contributions.

Measurement Accuracy

FitLab’s power crank system is tested via a Servo-controlled Test Rig (STR), equipped with a reference Load Cell.

FitLab’s power crank system is tested in order to experimentally acquire the MEASURING ACCURACY of all the parameters.

Numerous tests on FitLab’s power crank system leads to the following ACCURACY VALUES (valid for both left and right crank):

+/- 0.25 % F.S. MAX LINEARITY ERROR on force reading, from 0 to 1,800 N F.S.
+/- 0.5 mm MAX ERROR, moving +/- 10 mm force position along pedal’s axis
In the final analysis, FitLab’s power crank system is a vital tool to help discover how each cyclist’s body generates power, and how to best balance and optimize his or her position preliminarily on the “fit bike.”