By Paul Smith
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HOT!
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NOT!
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Rotor USA Tech specs: |
Ovalized Rings Reduce Strain, Add Comfort
The QXL rings are the latest product from Rotor, with increased ovalization over the standard Q-Rings — 16% ovalized vs. 10% with regular Q-Rings. Rotor intends this design not to replace standard Q-Rings, but rather to complement them.
Each is optimized for different rider profiles and situations. Standard Q rings aim to boost performance by varying the resistance in the pedal stroke. QXL rings claim to be more suited to higher output riders. I have ridden them all day at lower power
levels and would be comfortable recommending them for riders new to oval cranks.
The claim is that QXL chainrings are most noticeably beneficial when riding in conditions of high power delivery and consistent maximum effort, such as time trials, sprints and breakaways. The idea is that using Q-Rings will boost your performance by
varying drivetrain resistance during pedaling to help deal with your legs’ natural strengths and weakness.
The aim is to reduce the muscle effort at the weakest part of the pedal stroke and increase the possible power output during the part of the stroke with maximum power potential. I tested the QXL rings in a 53t/38t size. The ovalization changes the effective
gear size. For example, at the highest point on the pedal stroke in the big ring, it is the equivalent of a 57-tooth, and at the lowest point it shrinks to a 49-tooth.
Installation
Putting the rings on is a pretty straightforward operation for someone with moderate mechanical skills. It’s a matter of loosening five bolts (for Shimano), removing the existing rings and installing the new rings. There are five possible installation
positions. Rotor recommends starting with position three and changing from there as needed after the adaptation period — yes, there is a “burn in” time needed; more on that soon.
I was a little worried about the front derailleur adjustment, so I took it to my local bike shop to get it dialed in (thanks to Durham Cycles for the tweak). The key is to find the highest point on the big ring and, just like with round rings, place the
derailleur about 1-2mm above that. I later adjusted it myself after switching back to smaller round rings for a trip to the mountains and was able to set it up again without issue.
Getting used to the new stroke
It feels a little odd the first time you pedal with these rings installed. That said, it’s not as strange a feeling as you might expect from such a radically different shape. At the top of the pedal stroke there is less effort needed to push through,
which is the position where you generate the least amount of power. The crank shape then allows the most power to be generated in the 2 o’clock position where the effort can be maximized.
I found myself watching the chain for the first few miles, almost hypnotized as the chain moved up and down through the stroke. Watching from the side is even more dramatic.
The first ride was about adaptation. I went out solo on my local rolling Orange County roads for 54 miles. Each pedal stroke felt subtly different than what I’d been used to. Toward the end of the ride I hooked up with a buddy for the last 15 miles. Sitting
on his wheel I found I was able to hold the pace comfortably.
What became apparent was that my quads were on the edge of being sore. It feels like the muscles are activated in a different way, so that the larger and more powerful muscles get a chance to do more work. The soreness went away pretty quickly, though.
I felt like I adapted to the QXL rings in around 200 miles, after which my stroke while riding them started to feel natural.
Missing the top end
At the point in the testing process when my local group rides started to get faster, I noticed something telling. Within the group I’ve always had a reasonable sprint; however, I felt I was missing the top end of the power I normally can tap, that somehow
the power was coming too late in the pedal stroke.
I asked Rotor about this and the suggestion was made to move from the starting position of three to position two, since I was now fully adapted to riding ovalized rings. The change I felt was immediate. Now the power came right where I was expecting it
to, allowing me to get over the pedal stroke in a way that felt much more natural.
I found that the initial position is ideal for riders who prefer to spin in a reasonably high cadence in a time trial-like effort. But I tend to ride with a slightly lower cadence, so position two was more appropriate for me after the adaptation period.
(The photo shows different positions available on the ring.)
Here’s what Rotor’s documentation states re: the “symptoms” I was having:
“you need to lower cadence to be comfortable”, “pedaling resistance comes too late” and even “acceleration and sprinting is easy but maintaining speed if difficult”. The solution is to reduce the current OCP number by one step.
As mentioned above, there are five different positions available to mount the rings to meet the optimum pedaling style of the rider. All are explained with similarly detailed descriptions in Rotor’s documentation of the “symptoms” the user might be experiencing
– and the recommended adjustment solution.
Switching back to a conventional round crankset?
In the middle of the testing period, I took a trip with my riding buddies to the North Georgia mountains. It’s a wonderful area to ride and has many long and difficult climbs. Since the Rotor QXL rings didn’t have the low gearing I needed for these climbs,
I switched back to my Shimano Dura Ace 50/34 compact rings.
The first day of the trip went great. Although we didn’t do any of the big climbs that day, I rode strong and felt like I was on top of the gear. The second, and successive, days, when we hit the steep pitches, were very different. I felt that I was missing
the easy comfort that I had with the QXL rings. My legs tired easily, I had more leg strain and slight knee discomfort.
Rotor specifically advises against switching back to round rings, so this was an issue of my own making. When the ride in the mountains got tough, I found myself wishing for the oval rings.
I’m a Believer
The trip to Georgia was the real turning point for me. Before the trip I had enjoyed the QXL rings and found them easy to start riding and adapt to. However, once I switched back to round rings for that trip, the advantage I had gained from them became
apparent.
My pedal stroke felt choppy on the round rings, and I felt that I was probably wasting power. I can’t say if I was any faster, but I was certainly more comfortable on the QXL rings. After the trip, I switched back to the Rotor rings and felt the knee
pain reduce and the pedal stroke get smoother. That, to me, is the real advantage of making the switch.
Yes, the front shifting is a little more hesitant than with my Shimano setup, but the advantages are a more natural pedaling style and increased comfort.
If you have been considering making the switch to oval, it’s not a bank-breaking investment to give it a try.
September 2014
Paul Smith regularly reviews products for RBR. He’s an avid recreational roadie who lives in thePiedmont area of North Carolina. He commutes often, and his car is worth less than any of his bikes. Click to read Paul’s full bio.
nice one. thanks.