Friday, April 24, 2015
Review: Rotor 3D+ and Q Rings
I actually first came upon the idea of trying out Rotor cranks when investigating the options for a crank-based power meter a couple of years back. I had whittled my search down to the German company power2max's offerings which they pair with a selection of crank options, and within their range the Rotor 3D+ seemed to have good reports and an unusual look, and was designed for the BB30 bottom bracket of my new frame.
As I documented in my account of the bike build, my initial responses were positive. The cranks felt stiff. Rotor machines them from aluminium using their "trinity" drilling process in which three holes are drilled out along the length of the cranks in order to shed weight without reducing stiffness. Since I was dealing with quite a bit more weight in the power meter unit, I couldn't really compare them weight-wise to my previous Dura Ace crankset.
I had opted to just switch the chainrings from my other crankset, in part because I wanted to get a better idea of comparative merits without too many variations, so I had opted against the more radical change of fitting Rotor's iconic Q Rings. I had also selected the 130BCD version of the power2max, a choice that I would come to regret only a couple of months into riding my new set up when faced with the gradients of Northern Thailand.
After grinding my way up the monster of Doi Inthanon, narrowly escaping destroying my lower back on the last 5km to the 2600m peak at gradients above 20%, I became a sudden, immediate, convert to the compact crankset. Unfortunately the 130BCD dimensions of my power2max allowed nothing more compact than what I had. Major dilemma. If I'd had no intention of riding hills much, the choice was perhaps forgivable, but given that my immediate and long-term future was increasingly gradient-orientated, the choice seemed ridiculously short-sighted. Especially when I found out that for a 110BCD spider, Rotor now make chainrings up to a 55 - thereby eliminating entirely the need for the larger BCD format.
By chance, one of the bicycle shops near where I was staying in Chiang Mai was a Rotor dealer. Having had a couple of conversations with the owner about the local hills and my set up, I decided to see if the conversion of my chainrings to the elliptical Q Rings would make a difference. The claim is that the shape of the Q Rings takes you through the dead spot in your pedal stroke faster, so that your maximum engagement of power coincides with the wider point on the chainring. This should translate to a better application of your power when pushing hard.
I can actually see myself as having been in quite a fortunate position now. A lot of reviewers of the Q Rings are unable to be really certain of the advantage offered by the technology, whereas I, doing monster gradients on back-to-back days, could immediately feel the advantage the Q Rings afforded me even though the chainrings had the same number of teeth. I wasn't spinning exactly, but there was a smoothness to the grind that really made a difference on those 20%+ gradients.
There are often worries with chains slipping off elliptical rings during shifts at the front derailleur as highlighted by some of the pros losing their chains at crucial points in races. Though this has happened to me a couple of times, it is always due to the FD not being properly set up. The variation in distance of the chainring to the FD cage within the cycle is not that great, and as long as you have both rings set up in the same configuration, and well adjusted, there's no more chance of losing the chain than normal.
THE NEW ORDER
Next step was to get myself a compact set. I wasn't prepared to fork out for another power meter crankset, but since my older frame had a BSA threaded bottom bracket I decided to give the original Rotor 3D (BSA specific) cranks a try. This time with the 110BCD and a set of 50/34-tooth Q Rings. This is the basic "compact" chainring combination used often now by climbers.
As I've chronicled before, the transition was seamless. I immediately loved the compact set up and found myself increasingly less inclined to use the bike with the standard chainrings, using it mostly only when I want to know my power output for specific training or testing purposes.
The 3D cranks are apparently a little heavier than the 3D+, but irrelevant in my case as, with the Rotor spider instead of the power meter, they are definitely lighter. I can feel very little difference between the two models.
GETTING IT RIGHT
More recently I have built up another bike. This one is specifically a climber, and once again I've opted for the 3D+. This time it's the new 2015 model which aesthetically varies from the older one with a more subtle and understated logo. It's also a 110BCD of course, with the 50/34 Q Rings again. I don't currently have a power meter on this bike, but my intention is to add the Rotor InPower crank-spindle-based meter when it becomes available later this year.
Obviously on a brand new bike, the newness of everything devalues judgement of the performance of individual components of the bike, but I'd say that the new 3D+ feel even stiffer than the old ones. The weight difference is also now tangible, though I opted for the new MAS (Micro Adjust Spider) which adds a little more mass, and so a tiny bit of weight. However, when I get the InPower fitted, there is a proprietary software that can track your pedal stroke and give you a reading on exactly where you should micro-adjust the spider to the Q Rings to maximize the power application in your own pedal stroke.
So I guess you can assume from this that I am rather a devotee of Rotor's products across the board. I haven't yet tried the Q Ring XL which ovalizes the ring even further. I would be interested to try them of course, but not so interested that I'd go out of my way to find them - which i would need to.
Since you can tell I go by the maxim "if it ain't broke, don't fix it", it will probably have to wait until something else comes along to rattle my cage before I make a significant change (to my current hamster wheel!), but Rotor are consistently making stuff that works for me, so as far as their scope of expertise goes, and for the moment at least, I'm a happy end-user.
I will update once I have the new InPower meter and have optimized my set up even further.