Reliability and sensitivity of the Notio Konect to quantify coefficient of drag area in elite track cyclists

Abstract

Elite level cycling events are performed at speeds in excess of 50 km/h. At these speeds, over 90% of the resistance forces come from aerodynamic resistance (C D A). Recently bicycle-mounted pitot tubes, such as the Notio Konect (NK) have become more commercially available making C D A easier to measure. Its reliability and sensitivity would be useful for riders and coaches to be able to understand what constitutes as a change in C D A. Accordingly, the aim of this study was to establish the intra-and inter-effort reliability and sensitivity of the C D A measures of the NK. Seven elite level track riders were used in this study which was broken into two parts: (1) Reliability and (2) Sensitivity. For both parts of the experiment, riders performed identical efforts, riding at ∼50 km/h for six laps of a 250 m indoor velodrome. For reliability, the riders performed six efforts without any changes in position or resistance. For sensitivity, they performed the efforts with a rod with discs of a known diameters attached at each end to vary the C D A by a known amount. For the reliability assessment, low coefficient of variation of intra -(0.47%) and inter-effort (0.9%) reliability were measured. With regards to sensitivity, the smallest changes in resistance (from 5 -6 cm, i.e. 1.2% or 0.002 m 2 ) was identified by the NK. The data in this experiment suggests that the NK is a highly reliable in measuring C D A can detect changes up to at least 1.2% in an indoor velodrome using elite level track riders. Highlights. The Notio Konect showed high levels of inter-and intra-effort reliability.. The Notio Konect could detect a change as small as 1.2% in aerodynamic drag.. The findings suggest that the Notio Konect is suitable for detecting small changes in aerodynamic drag in a velodrome setting.

Cycling modelling under uncontrolled outdoor conditions using a wearable sensor and different meteorological measurement methods

“…13 A subsequent study has confirmed the reliability of the Notio in an indoor velodrome and has shown that this technology can detect small changes in C d A (1.2%). 14 In addition, the C d A calculated during field tests on a straight and flat road of 400 m with the mathematical model integrating meteorological data of a Velocomp Aeropod would be consistent with the values from wind tunnel testing. 5 However, none of these studies tested the validity of this type of device under real and uncontrolled conditions when the cyclist must face the force of the wind and ride at different speeds on varied courses made up of turns, climbs and descents.…”

Validity of a novel device for indoor analysis of cyclists’ drag area

“…The purpose of this study was to evaluate the validity and sensitivity to changes in cyclist position with respect to the measured CdA between the Notio Aerostick device (Kordi et al, 2021;Valenzuela et al, 2020 ¶ ) and two other mathematical models, VE (Dyer & Disley, 2018) and Martin (Martin et al, 2006). Our main finding is that, although the level of agreement of Notio Aerostick with both formulas is satisfactory (ICC>80%), with low and non-systematic error bias, and the differences in CdA are not significant in any of the positions, our results show that Notio Aerostick gives slightly lower values than those obtained by the formulas.…”

“…These include mathematical models, such as Virtual Elevation (VE) (Dyer & Disley, 2018) and the Martin's Model (Martin et al, 2006), but also aerosticks devices such as the Notio Aerostick (Argon 18; Montreal, Canada), Aero-Lab.tech (Strathcona Calgary, Canada), and Velocomp LLC (Stuart, Florida, EE.UU). The main feature of this devices is that it includes a pressure sensor capable of measuring wind speed, which together with other external sensors resolve an energy balance equation to obtain a composite value that includes the aerodynamic drag coefficient multiplied by the frontal area; that is, the so called coefficient of aerodynamic drag (CdA) (Kordi et al, 2021;Valenzuela et al, 2020 ¶ ). In the case of aerostick Notio Aerostick, it uses its own equation that has not been published.…”

“…To our knowledge, only two articles have been published to date that analyse the reliability and validity of the Notio Aerostick device (Kordi et al, 2021;Valenzuela et al, 2020 ¶ ). Neither of these analysed its sensitivity for detecting position changes when assessing CdA in an aerodynamic assessment protocol, and in a real context with professional cyclists.…”

“…Neither of these analysed its sensitivity for detecting position changes when assessing CdA in an aerodynamic assessment protocol, and in a real context with professional cyclists. The aim of this study is, therefore, to test the reliability and degree of agreement in the CdA evaluation of the aerostick Notio Aerostick (Kordi et al, 2021;Valenzuela et al, 2020 ¶ ) compared to the VE (Dyer & Disley, 2018) and Martin (Martin et al, 2006) mathematical models, both previously validated with the gold standard wind tunnel method. Changes in positional adjustments are considered for further comparisons.…”