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

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 (CDA). Recently bicycle-mounted pitot tubes, such as the Notio Konect (NK) have become more commercially available making CDA 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 CDA. Accordingly, the aim of this study was to establish the intra- and inter-effort reliability and sensitivity of the CDA 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 CDA 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 m2) was identified by the NK. The data in this experiment suggests that the NK is a highly reliable in measuring CDA can detect changes up to at least 1.2% in an indoor velodrome using elite level track riders. HighlightsThe 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.

Assessment of bike handling during cycling individual time trials with a novel analytical technique adapted from motorcycle racing.

A methodology to study bike handling of cyclists during individual time trials (ITT) is presented. Lateral and longitudinal accelerations were estimated from GPS data of professional cyclists (n = 53) racing in two ITT of different length and technical content. Acceleration points were plotted on a plot (g-g diagram) and they were enclosed in an ellipse. A correlation analysis was conducted between the area of the ellipse and the final ITT ranking. It was hypothesised that a larger area was associated with a better performance. An analytical model for the bike-cyclist system dynamics was used to conduct a parametric analysis on the influence of riding position on the shape of the g-g diagram. A moderate (n = 27, r = -0.40, p = 0.038) and a very large (n = 26, r = -0.83, p < 0.0001) association were found between the area of the enclosing ellipse and the final ranking in the two ITT. Interestingly, this association was larger in the shorter race with higher technical content. The analytical model suggested that maximal decelerations are highly influenced by the cycling position, road slope and speed. This investigation, for the first time, explores a novel methodology that can provide insights into bike handling, a large unexplored area of cycling performance.