What is a QXL chainring?
The new QXL is a Q-Ring with increased ovalization. They have a similar shape to standard Q-Rings, ensuring exceptional drivetrain stability.
How do QXL rings fit in our current collection?
QXL rings do not replace standard Q-Rings, rather complement them. Similar to how different rim heights coexist amongst wheelsets, each being optimized for different situations, the Q and QXL rings coexist, optimized for different rider profiles.
QXL chainrings will ensure further growth of the non-circular chainring market, which ROTOR expects will dominate cycling sooner rather than later.
Why did we design QXL rings?
Despite the fact that Q-Rings have won a startling amount of cycling’s major titles (Olympic Golds, Tour de France, Vuelta España, World championships in Road, TT, Cyclocross, Marathon MTB, Duathlon, Triathlon and much, much more) a product line that doesn’t develop appears to remain stagnant. Q-Rings have been incrementally improved with each individual production batch throughout the 6 years they have been on the market, but no major redesign warranting large scale “new version” communication has been made. ROTOR aims to be dynamic in its Q product collection.
ROTOR believes that standard Q-Rings offer an optimal adaptation-stability-biomechanical balance for most cyclists, however we are aware of scientific research and feedback from pro riders that shows that greater ovality can be desirable and useful for certain athletes. Not all riders have the same muscle build, riding form, or pedaling style. This is an opportunity we needed to design a new product to properly exploit. QXL rings are designed more for a type of rider than a specific cycling discipline.
When we applied our biomechanical and engineering knowledge to an increased ovality, we found that the feedback was positive from many professional riders previously skeptical or lukewarm towards Q-Rings. These athletes predominantly reported an improved cycling experience, particularly when pedaling out of the saddle and accelerating. We have seen that QXL chainrings are most noticeable when riding in conditions of high power delivery and consistent maximum (peak) effort, like time trials, sprints, breakaways, riding styles that involve frequent out of the saddle riding, etc.
QXL rings are preferential for riders with dominant fast-twitch muscle (fast deactivation dynamics) build looking for more ovality to achieve their potential. These are typically “powerful” riders with larger muscle mass-producing a higher peak and average power output. For example, sprinters tend to have predominantly fast twitch muscle build. This makes an increased degree of ovality optimal because these riders benefit from the decreased negative work the grater ovality offers. QXL rings noticeably improve out of the saddle riding (sprint or climb), helping most during moments of maximum effort when the "dead spots" become far more critical.
Standard Q-Rings are preferential for riders with dominant slow-twitch muscle (slow deactivation dynamics) build looking for increased smoothness to achieve their potential. These are typically riders with lower peak and average power output. For example, endurance cyclists tend to have predominately slow-twitch muscle fibers with slower deactivation dynamics. This makes a smaller degree of ovality preferable by keeping muscle activation optimized. Standard Q-Rings noticeably improve seated “cruising” riding, over long distances where pedaling smoothness is critical for efficiency.
Popular discussion amongst scientists indicates that increased ovality can offer benefits. Optimal chainring ovality for an individual cyclist appears to vary depending on slow versus fast twitch muscle fiber type and activation-deactivation dynamics. We tested our current Q-Rings according to more extreme values of activation and deactivation, which showed that the optimal ovality varied according to muscle type and activation/deactivation speeds.
With the use of oval chainrings, crank velocity slows in the downstroke, maximizing the time spent in the power phase. Greater ovality can allow for full muscle activation and greater positive work and therefore more power produced. Through the dead spots, crank velocity speeds back up, which can allow muscles to deactivate faster, meaning less negative work is produced.
So, a balance must be struck between maximizing the time in the power phase (downstroke) and minimizing the negative work that results while the muscles are deactivating, meaning different athletes may benefit from varying ovality – or at the very least, will feel more comfortable with one vs the other.
We will keep you all updated as more research results become available.