25 January 2009

bikefix Initial Review: Rotor Q-Ring chainring

Several years ago, while working at a shop in Cambridge, I remember the owner selling a number of crazy, heavy Spanish cranksets. They were Rotor's weirdly articulated RS4s and despite their anchor-like weight were popular among folks pursuing a PRs on the Mount Washington hillclimb. I had the opportunity to ride a set and they felt like riding a fixed gear- normal for the most part, but the feet would zoom through the dead spot without effort. Despite their claims of effective muscle use and efficiency, they never really took off- likely thanks not only to their weight but also the $800 or so price tag (this was at a time before carbon cranks made such figures seem reasonable).

In the years since, I've noticed some clever things coming from Rotor, including very light threads with very cool dual-threaded fasteners (which are different pitches, not opposing as I'd originally thought), some very light CNC'd cranks and UCI World Championship-winning (women's 2006 'cross worlds) elliptical chainrings. When I stopped by the Rotor stand at Interbike this year, I saw a single speed mounted with one of the company's 'rings. Talking to Kervin, I found that they'd been running the Q-Rings on singlespeed and fixed-gear bikes without problem- the chain does slacken twice per pedal revolution, but it's at the spots where the least force is applied and where the rider is least likely to be in rough terrain (at 12:00 and 6:00) . He gave me some info to add to my bag o' propaganda and let me think on it for a while.

By the middle of each winter, many of us in El Burque begin frantically training, as Tucson's 24 Hours in the Old Pueblo is just around the corner. By the end of December, many of us become quite concerned about our commitment to 24-hour racing in the middle of winter and start looking for any equipment advantage possible, no matter how dubious. I started thinking about giving a Rotor chainring a shot.

Now, if anyone had told me a couple of years ago that I'd be trying to wring additional performance out of a $95 chainring, I would probably have said that that person were full of shit. That said, the specter of bonking hard sometime after midnight and basically hating life is a big one and can compel one to take desperate measures. Besides, Rotor claim that scientific studies have proven that Q-Rings grant a rider an average 4.1% increase in power output, 9.1% decrease in lactate levels and an unspecified amount happier knees- bold claims, but if true they make for a bargain. Heck- even Cervelo's new "TestTeam" will be using them for '09- and that's a company that seems to do their homework. An order was placed and, in the beginning of January, a small package from Colorado Springs arrived on my stoop.

Given the problems that I'd had with my tensioner, a drivetrain rethink was in order. My pristine King Kog was kept but the track chain replaced with a narrower KMC 8-speed Z-Chain. Once a half-link was sourced and my chainline sorted out, I was ready to roll. Man that thing looks weird in motion. My attempting at ghosting doesn't really do it justice, but it is pretty odd to see. As Kervin promised, though, and despite what works out to be a 3.5t difference between smallest and largest effective diameters, the Convert was up to the task. With chain tension set with a crank at 3:00, there really isn't much slack at 6:00. A sprung tensioner (like Surly's Singulator) might be better in theory, but I wouldn't have any problem recommending the Q-Ring for use with a sliding dropout or eccentric BB frame. I should note that this is a road compact (110mm BCD) chainring sitting on those road compact cranks- mountain patterns are available though and should work similarly.

I've got about 25 hours on the Q-Ring so far and here are my impressions: It's weird. As someone who rides a fixie from time to time (though not religiously), I think that I have a pretty decent spin. The Q-Ring takes that hard-earned spin and throws it out the window. On my first ride, I could actually feel the hub disengaging as the chain slowed (cranks near vertical) and reengaging as it sped up (cranks nearing horizontal). During low-speed mashing, it felt like I was pushing a taller gear than before- effectively a 36 over my usual 34. At cardiac redline, it felt like a much taller gear. Last week, I sat down with the instructions and decided to go from the 'ring's middle (#3) position to the slightly delayed #4. This moved the tallest effective gear a bit and made a huge difference. The highest leverage now comes a bit later, when I'm really on top of the cranks and takes away a lot of the mash-y feeling. It's safe to say that the Q-Ring no longer feels odd at all. Am I going faster? It's hard to tell. I have been feeling fresher at the end of long (4-5 hour) SS rides- but that could also be a good training plan at work. While I may swap my old 'ring back on for a ride or two between now and 24HitOP, I plan on rocking (running?) the Q-Ring for my share of this year's race. I'm excited by the possibility but know now that if I come up short, it'll be my own damn fault. Doh.

marc

www.rotorusa.com

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