Q-Rings have been making quiet headway into the mainstream of bike racing in the past few years thanks in part to their sponsorship of a number of successful professional riders.
These elliptical chainrings claim to increase power generation, reduce fatigue and help prevent injury by varying the effective size of the chainring throughout the pedal stroke.
If you’e ever used the now defunct Shimano BioPace chainring system that was prevalent on bikes in the late 1980s you’ll know what to expect here in terms of sensation but the crucial difference is that Rotor have sought to avoid the knee problems associated with the Shimano system.
The ‘Q-Ring’ is based on a simplified theme of the same company’s Rotor cranks that seek to minimise the inertia that happens after 20 degrees of crank rotation through what is commonly termed ‘the dead spot’.
The larger diameter of the ellipse is positioned to coincide with the down stroke of the pedalling cycle, increasing the gear ratio just when the leg is best able to provide maximum force.
The positioning of the smallest gear ratio coincides with the pedal reaching the ‘dead spot’ at the bottom of the pedalling cycle.
Published scientiﬁc data and anecdotal evidence on the whole support Rotor’s claims, and we did get increased readings on our power meter – around three percent. However, we didn’t notice any less muscle soreness after long rides.
The location of the maximum gear ratio is adjustable between five settings according to personal preference, so it’s worth following the instructions available to get your ideal setting, as the setup for standing sprints is not the same as that for long rides.
The carefully designed chainring shape ensures the variation of gearing throughout each revolution doesn’t destroy the sensation of smooth spinning.
Because the elliptical chainring moves the chain away from the front derailleur the Q-Rings do slightly delay shifts compared with other good quality aftermarket offerings.
For riders willing to commit the money to trying something outside the norm, it could be worth putting up with the slightly slower changes.
Q-Rings are available in various sizes to fit road, track and mountain bikes. You’ll need to raise the front mech to account for the ovalisation and shifts between the small to the large chainring.
While there were no problems on a bike fitted with a band-on front mech it may not be possible to raise the mech sufficiently on frames with a braze-on front mech mounting point.