Time Trial / Time Trialling / TT

Oh but they're better for 'recovery'. cough bullshit cough

Or even worse due to "smoothness" as mentioned at the end of the 1st para here:

Cyclists participating in the present study were accustomed to ride with circular rings and thus their cycling positions as well as other biomechanical parameters were optimized according to such conventional chainring design (Neptune and Herzog, 2000). When changing from C-rings to Q-rings, the oval chainring design might alter the usual pattern of force application, which may induce changes in the biomechanical patterns of cyclists. In theory, such changes could increase the associated metabolic cost, most likely due to the recruitment of different muscle fibres. However, we found similar levels of lactate production and oxygen consumption for both chainring designs. A possible explanation is that the particular design of the Q-rings not only optimizes the way the force is exerted throughout a crank cycle, but it also makes power delivery through the duty cycle more continuous. Importantly, all the cyclists participating in the experiments reported that pedalling with the Q-rings was “smoother”. Thus, it might be hypothesized that the “smoother” pedal action associated with the Q-rings would bring about energy savings that would compensate for the supposed muscular disadvantage (change in biomechanical pattern) associated with this design. In this connection, it should be mentioned that, while the smooth pedalling of the Q-rings may be theoretically ideal, from a physiological point of view it may be beneficial to reduce pedal force during sections of the pedal stroke to allow localized recovery and reduce pressure to allow blood flow to the muscle, especially at high exercise intensities.

In our protocol, fatigue was assessed directly through measurements of maximal isometric force and also indirectly by the average amplitude of the EMG signal (Vollestad, 1997). It was found that the changes in force between the isometric contractions performed before and after the incremental test were comparable for Q-rings and C-rings (Table 4), which suggests that the same fatigue was experienced under both chainring conditions. Similarly, the decline in EMG produced by the fatiguing incremental test was comparable for Q-rings and C-rings (Table 5), thereby reinforcing the view that circular and non-circular rings result in similar fatigue.

It must be mentioned that, for the incremental maximal test, the maximal power production values were higher for Q-rings than for C-rings (371 ± 30 vs. 355 ± 29 W, respectively), and that, for each of the subsequent short sprints, power values were 2.5–6.5% greater for the Q-rings. Interestingly, the extent of the improvements with the Q-rings found here resembled those obtained by other authors using the Rotor system (Rodríguez-Marroyo et al., 2009). Thus, **although the differences in physiological variables between circular and non-circular chainrings did not reach statistical significance, the possibility that Q-rings result in slight improvement during on-road cycling performance cannot be excluded. **Thus, whether or not the oval Q-rings could induce any improvement in time trial performance remains to be elucidated (Peiffer and Abbiss, 2010). Indeed, the determinants of performance in an individual time trial are more complex and the experimental protocol followed in the present study did not allow conclusions to be drawn in this direction (Abbiss and Laursen, 2005; De Koning et al., 1999).

It's strange riders find them best for TTs and long, smooth climbs whilst this seems to suggest any benefit would be most likely in a sprint.