There’s been much buzz about non-circular chainrings for the past few years, and this week Spanish firm Rotor, who specialise in non-circular chainrings and cranks, have launched their Q-Ring Test demo programme. This allows you to fit the rings to your own bike so you can try them out before deciding if they’re right for you.
Rotor reckon the proof is in the ride and will be supplying UK dealers with special red anodised chainrings that can either be fitted to their own demo bikes, or to a customers bike. Which is a very good way of finding out if non-circular rings are for you, rather than taking an expensive punt on them.
Non-circular chainrings have been around for over a hundred years, but it was Shimano's ill-fated Biopace oval rings in the latet '80s that arguably did a lot of damage for the non-circular rings. That didn't deter Rotor launching their Q-Ring in 2005 though, and they've slowly been gaining traction, particuarly in hte pro peloton, over the years.
Non-circular chainrings are an interesting concept, and the theories behind them does sound convincing. Rotor have plenty of science to support their Rotor Rings in providing improved efficiency and power with the result increased speed. What the chainrings do is to vary the effective chainring size to help you push through the dead spot.
So at the top and bottom of the stroke a smaller effective chainring helps you push faster through this zone, and with a bigger effective chainring at the point where most power is produced in the pedalling stroke. If some of the studies are to be believed, there’s as much as 6% power increase which, were slender gains are hard to come by, is potentially significant.
That's the theory anyway. It's worth having a look at this study that Rotor released last year if you want to see some interesting data on the claimed benefits. In it, they claimed "subjects completed the time trial on average 1.6 seconds faster, increased average speed approximately 0.7 kph and increased average power approximately 26 watts."
Throw into the non-circular versus circular chainrings debate is to look at what the professionals ride, though you can bet they’re often encouraged to ride particular products. That said, there’s been some uptake of non-circular rings, quite a few riders have been riding Rotor Rings. Tyler Farrar and Ramunas Navardauskas, who won stage 11 of the Giro d'Italia, both use them.
More famously perhaps, Bradley Wiggins rode O'symetric (a French firm also specialising in non-circular rings) chainrings to Tour de France victory last year. They’re similar to Rotor’s rings. Interestingly, Wiggo has stopped riding those rings this season... Chris Froome however is still racing them this season.
So don't take Rotor's word for it, pop along to your local Rotor dealer and try a set of non-circular chainrings out. If you do, let us know how you get on. You can find your nearest dealer at hwww.rotoruk.co.uk/stock.html
David has worked on the road.cc tech team since July 2012. Previously he was editor of Bikemagic.com and before that staff writer at RCUK. He's a seasoned cyclist of all disciplines, from road to mountain biking, touring to cyclo-cross, he only wishes he had time to ride them all. He's mildly competitive, though he'll never admit it, and is a frequent road racer but is too lazy to do really well. He currently resides in the Cotswolds.