Rotor Q-ring advice

[Osiris]

On many recumbent seats, this range of pelvis motion is not possible because the pelvis is supporting the weight of the rider and is "essentially" fixed or certainly not as easy to move fluidly in sync with the pedaling. This probably explains the extra power racers get with the railgun seat.

Odd that in none of the conversations I've had with Kent Polk about his Railgun seat did he mention anyone gaining power from it. In fact, he wasn't a bit surprised when I mentioned that my power output actually dropped when switching to the Railgun seat. Both he and John Schlitter indicated that a loss in power is a common result of increasing the angle of recline, which the Railgun seat does. The reason I was able to go faster using it had nothing to do with increased power, but improved aerodynamics. The bent I was able to produce the most power on was my Bacchetta CA2. Unfortunately it had the most upright seat of all of them, and the drag this produced resulted in slower speeds even at higher power levels.

 

[ed72]

railgun power

http://synthetictransport.com/railgun/faq.html

I gained power lowering my M5 seat, so there.

 

[ed72]

Whether an individual rider is willing to spend say $200 to try Rotor rings depends on their pain level or desire for more power and/or comfort. Rotor's studies aren't great but then again, remember the old dogma around shaving one's legs ....only saves 6 seconds in a 40 km TT? The scientist based that off one run in a wind tunnel on one mannequin leg with some fake hair glued to it. Real racers knew otherwise. The science was pure BS. Unfortunately, Spesh spilled the beans.

I had Rotor QXL on three DF bikes. Bike 1 was a custom built and custom fit by some of the best, this was my randonneuring bike and I think there was a small power and lower lactate in the tempo range as previously written. Think because the results were within the margin of error and I was unwilling to perform sufficient replicates for statistical certainty. Bike 2 was a Cervelo S3 setup for TT and I could not see more power but the position was constrained. I bought another frame made from the same material as bike 1 but with different geometry although all the equipment was exact to bike 1 and with the same power meter. I did my 5 minute interval hill on Bike 3 on the maiden ride. A hill that I would do 5x5 or 6x5 at VO2 max every 5 days. My times were usually 4:40-4:50. First time on the new frame, I did 4:04 and never did more than 4:27. A coach told me that frame had magic in it, don't sell it. Bike 3 had the same Rotor 3D+ crank, same 177.5, and same 53/39 rings with 130 BCD. Same material but different geometry. So, it is a fit and bio thing as Balor had suggested. Whether QXL rings help you? Who knows.

I kept the 177.5mm Rotor 3D+ with 53/39 QXL rings on my randonneuring bike because they allowed me to do multiple 300+ mile days with 15-20,000 feet climbing and to have less leg strain than circular rings. This is also why I used them on the Trans Am bike race. As I have said many times, YMMV.

I just got a real bump in power for 300 bucks. Increases that in the past I have spent 6+ months training and real money on coaches, fitting, camps, etc. For some, this is a lot of money and I respect that. For others who struggle with pain or want easier climbing and have the money, it could help (like bike 3, maybe). It also might not help (like bike 1 for me)

Why am I going to try shorter cranks with QXL rings on my bent? Because those who a respect have done so and it might work for me. I don't know if they will or not. I do know how to make the measurements.

http://www.rotorbikeusa.com/science.html

 

[Balor]

The "argument from authority" is a classic logical fallacy that should be "considered" only in philosophy 101 courses, not when trying to make a rationally informed purchase decision.

Ok, let's restate:
Argument from authority comes in two flavours: one is totally fallacious, when someone who is 'authority' makes claims in a field outside of his expertise - say, a molecular biologist making a claim about evolution, or a chemistry PHD making claims about medicine... or a politician making ANY claim at all, ehehe. That's a subtype of 'halo effect' fallacy in fact.
The other is when an expert is making a claim that is INSIDE his area of expertise. Relying on expert advice is a useful heuristic. That's what got us, humans, from the caves into space - it is a MASSIVE time-saver, allowing you to tap into knowledge you'll spend lifetimes (that you do not have) trying to recreate from scratch otherwise.
Of course, experts are humans and humans are inherently fallible, trust me, I'm familiar with how riddled with holes our judgement is... including 'bias blind spot' one should never forget about.
I, for instance, was not happy with expert advice about 'MBB handling' (both 'French School' and 'American School') and how one should simply get used to it's quirks, but I got enough benefit from it to justify time to amass 'expert knowledge' myself to form my own opinion and expense to make a few prototypes that worked out just fine if you ask me. Bicycle seems to be a deceptively simple system, but it's dynamics at speed and interaction with rider and road surface via pneumatic tires is anything but.
Biomechanics, on the other hand, is an *extremely* complex subject from get go because it does not only taps into your body that is mind-bogglingly complex system of levers and actuators with nonlinear dynamics, but also your mind - neuromuscular adaptations and complex feedback systems that lie way below level of conscious awareness.
'Placebo effect' is a real deal and when it comes to marginal gains can be, literally, orders of magnitude larger than values being tested. Still, we have tools that can objectively evaluate performance now, and we can sift stuff that 'makes' us faster VS what 'feels fast'.

Hence, unless you can reconstruct entire model of pedalling dynamics from metabolic biochemistry, blood circulation, muscular fibers and neuronal firings to exact power output in watts (and I'm reasonably sure no person alive is capable of that) - it can be useful to listen to expert advice, but be aware of it's limitations and should be willing to try things that 'make sense', but may not actually do anything for you.
How far should you go depends on how much pleasure you draw from experimenting and how intolerant to failures you are...

 

[Balor]

An other thing about biomechanics and being cautious about relying on data from 'pros'. Unless you are also a 'pro', they have vastly different levels of training (as in - specific adaptations), 'pharmacological' support (I'm not even talking about doping, though it is obviously included) and *values* as you are.
They might be willing to subject themselves to levels of pain and injury (and weather it with relative impunity) that will cripple you both physiologically and psychologically, and totally disregard stuff that might be a bit detrimental to performance, but cause massive increase in comfort (like, say, riding recumbents ).

Or, again, like recumbents, some stuff we may use with impunity is forbidden to Pros by some sort of arbitrary regulation or an other.
All in all, there should be a balance between keeping an open mind and having it so open our brains fall out (c).

 

[ed72]

Odd that in none of the conversations I've had with Kent Polk about his Railgun seat did he mention anyone gaining power from it. In fact, he wasn't a bit surprised when I mentioned that my power output actually dropped when switching to the Railgun seat. Both he and John Schlitter indicated that a loss in power is a common result of increasing the angle of recline, which the Railgun seat does. The reason I was able to go faster using it had nothing to do with increased power, but improved aerodynamics. The bent I was able to produce the most power on was my Bacchetta CA2. Unfortunately it had the most upright seat of all of them, and the drag this produced resulted in slower speeds even at higher power levels.

The railgun FAQ uses the word "power" 40 times. It also claims faster speeds climbing. How pray tell does that happen without more power.

"The seat shape is designed for power." Kent's word exactly.

http://rbentonline.org/YaBB.pl?num=1386937343;start=all
​

If you take the time to read all of his posts, you will see that he believes the increased power comes from elevating the lower back, which takes pressure off the sacrum and localized peripheral nerves and blood vessels. Maybe? Might explain my numb feet. I have a different opinion why his seat would allow faster climbing and it is biomechanical, not neurologial or vascular.

http://members.home.nl/vd.kraats/recumbent/oval.html

I only spoke to Kent Polk once, after a 212 mile ride that was supposed to be 300K brevet but a police detour made it much longer. In fact, his recumbent was the first one that I had even scene. I wanted to meet the guy who finished half an hour ahead of me on my fat tired, fendered rando bike. His machine looked like a space ship to me back then. If you read his FAQ, you can see his honesty. He can't take the time and money to produce true scientific studies to support his product, nor can Rotor. Proper studies ain't cheap and like I said, I haven't seen one ever in the bike industry.

I am more simple. I think of Authority as Power. There are two types of power, at least in corporate hierarchies. Positional power and knowledge. Nobody messes with either. The knowledge guy is the only one respected, usually.

BTW....you used Q rings and not QXL and if my memory serves, you were told that they seemed to be installed incorrectly, you did not respond. And your response to the esteemed RChung was incredibly disrespectful but maybe I have that all wrong.

 

[ed72]

The following supports what I sense in my legs using QXL rings but especially the Rotor RS4X cranks, the peak forces in my quads are lower. It shows a longer duration of lower forces but overall higher power for the ovals. Of course, the naysayers will just say it is confirmation bias but I do not have a theory or belief, I have real data showing a benefit for me (on some of my bikes, LOL). This aspect would be of no interest to those doing 200m dragstrip type speed runs on their bikes but on longer rides, it does matter. The link allows one to compute the forces based upon degree of ovalness.....I buy it.

http://members.home.nl/vd.kraats/recumbent/oval.html

This all reminds me of hill climbing pedaling technique advocated by a University cycling coach up in the Boston area (Ed Sassler). Dismissed. Too different. But if one looks at what he advocates and compares to Greg Lemond climbing L'Alpe d'Huez, there is a similar rhythm or at least a rhyme. I watched his free videos and after several training sessions, my climbing improved for sure. Placecbo? Who cares, the power meter ain't lying nor is the stopwatch for that matter.

 

[Osiris]

Ok, let's restate:
Argument from authority comes in two flavours: one is totally fallacious, when someone who is 'authority' makes claims in a field outside of his expertise - say, a molecular biologist making a claim about evolution, or a chemistry PHD making claims about medicine... or a politician making ANY claim at all, ehehe. That's a subtype of 'halo effect' fallacy in fact.
The other is when an expert is making a claim that is INSIDE his area of expertise.

Absolutely, but bear in mind that professional athletes are not scientists. Their trainers are likely to have far more expertise than they do. It's not news to anyone that pro athletes have been known to make false claims. Sometimes they make those claims because they're paid to. Sometimes they make them because they honestly believe them to be true when they aren't. Sometimes they make them because they happen to be true for them, but wrongly assume it will be true for everyone. They make those claims because they are not the experts people commonly assume they are.

 

[Osiris]

The railgun FAQ uses the word "power" 40 times. It also claims faster speeds climbing. How pray tell does that happen without more power.

"The seat shape is designed for power." Kent's word exactly.

http://rbentonline.org/YaBB.pl?num=1386937343;start=all​

​

Let's take a close look at exactly what Kent's position is:

"People point to some writeups done a few years back claiming that the closed, more upright position allowed for greater power generation. I have no idea how those experiments were performed. As a research scientist for many years, I am fully aware of how important it is to properly set up and perform experiments and how badly the results can go astray when this is not done. I also know that experimental results can be taken out of context and accomplish the same thing. I'm not sure what the case here is but I do firmly believe and have shown with my own results (and others who have used my methods) that the closed position simply does not guarantee more power or better/faster climbing. Nor does the open, low seatback angle. Success depends on getting things right! And that means you will need to spend some time investigating what is right for you and how to prevent possible coccyx and sacrum issues from inhibiting comfort and power production. Existing recumbent designs tend to not provide the sort of protection for the coccyx and sacrum that many (if not most) people need. You will need to find something that works. I will say that a few seats I've seen recently are starting to get closer and hopefully are beginning to recognize these issues."

Notice how conservative his claims actually are. He freely concedes that the open, low seatback angle "does not guarantee more power or better/faster climbing". This is why he took no issue with my report that swapping out the stock M5 seat for his Railgun actually resulted in a power loss. When I inquired about purchasing a shorter seat post, John Schlitter warned me that a greater angle of recline may result in a power loss, so I should not assume that the improved aerodynamics alone would increase my speed. That would only be true if the resulting reduction in drag more than compensated for any resulting power loss, which it fortunately did in my case. My final appraisal of the Railgun seat after about a year of use was that despite there being no power gains, the advantages of the Railgun were much greater comfort and reduced pedaling effort at elevated speeds due to its superior aerodynamics. Kent took no issue with this assessment. He never insisted that the seat will produce more power, and even added that, "the seat doesn't work for everybody".

Proper studies ain't cheap and like I said, I haven't seen one ever in the bike industry.

Have you seen the studies done at the University of Bath featured by GCN?

BTW....you used Q rings and not QXL and if my memory serves, you were told that they seemed to be installed incorrectly, you did not respond.

Yes, that's what another forum member thought. I took his advice and made the suggested changes. It made no difference. And as I said previously, I've had Q-rings on two road bikes, following the manufacturer's installation instructions to the letter. They certainly feel different than conventional round rings, but there was no measurable performance improvement.

And your response to the esteemed RChung was incredibly disrespectful but maybe I have that all wrong.

Yes, you certainly might.

 

[Balor]

Notice how conservative his claims actually are. He freely concedes that the open, low seatback angle "does not guarantee more power or better/faster climbing". This is why he took no issue with my report that swapping out the stock M5 seat for his Railgun actually resulted in a power loss. When I inquired about purchasing a shorter seat post, John Schlitter warned me that a greater angle of recline may result in a power loss, so I should not assume that the improved aerodynamics alone would increase my speed. That would only be true if the resulting reduction in drag more than compensated for any resulting power loss, which it fortunately did in my case. My final appraisal of the Railgun seat after about a year of use was that despite there being no power gains, the advantages of the Railgun were much greater comfort and reduced pedaling effort at elevated due to its superior aerodynamics. Kent took no issue with this assessment. He never insisted that the seat will produce more power, and even added that, "the seat doesn't work for everybody".

I think that's a lot of dancing about what amounts to importance of bracing and 'tissue hysteresis' that people are just embarrassed to bring up into the open if you ask me.
Well, 'Squishy butt makes me lose power!' does sound embarrassing. Since I'm past redemption, I've said it so you don't have to .
In my case, bar pulling and bridging work far better (though former is tiring and cause callouses). I'll be experimenting with shoulder boosters as on hour record bikes and be sharing my results as well.

 

[Osiris]

I think that's a lot of dancing about what amounts to importance of bracing and 'tissue hysteresis' that people are just embarrassed to bring up into the open if you ask me.
Well, 'Squishy butt makes me lose power!' does sound embarrassing. Since I'm past redemption, I've said it so you don't have to .
In my case, bar pulling and bridging work far better (though former is tiring and cause callouses). I'll be experimenting with shoulder boosters as on hour record bikes and be sharing my results as well.

Have you tested your theory with a power meter?

 

[Balor]

Have you tested your theory with a power meter?

In a WAY, yes. I've taped slabs of meat to the shoes and compared pedalling with and w/o those at a set HR on a trainer that measures power. I think I've brought it up somewhere, I can dig up strava data but that is by no means 'scientific' and in a 'well, duh!' territory (power drop was pretty significant at same HR). Other people been monitoring their workouts in the mirror and seen bobbing up and down to the pedal strokes. People often claim that flexy seats (like mesh) cost them a lot of power, too. Anecdotes, again. And my theory that MBB bikes, Cruzbike especially, derive a lot of their prowess not just from 'boom swinging' (I never used that) or stiff, short drivetrain (certainly a factor, but on a matter of 4-5 percent), but 'cockpit' that facilitate bar-pulling instead.

Unfortunately, I cannot afford something like Garmin Pedals and measure power 'in the field'.
Plus, how can I test it on a bent? Quickly lose 50 pounds and make new measurements? Not that I wouldn't like that, but that surely cannot happen overnight and too much other factors are going to be involved!

Cover the seat with the meat? That would take a LOT of meat, though doable...
Would, say, adding extra (soft) seat padding and comparing data be a meaningful test? I'll still need to find a material that about equals to human flesh in 'spring coefficient' and damping quality...

 

[Gary123]

Just when toy thought you'd heard it all...

 

[Osiris]

In a WAY, yes. I've taped slabs of meat to the shoes and compared pedalling with and w/o those at a set HR on a trainer that measures power. I think I've brought it up somewhere, I can dig up strava data but that is by no means 'scientific' and in a 'well, duh!' territory (power drop was pretty significant at same HR). Other people been monitoring their workouts in the mirror and seen bobbing up and down to the pedal strokes. People often claim that flexy seats (like mesh) cost them a lot of power, too. Anecdotes, again. And my theory that MBB bikes, Cruzbike especially, derive a lot of their prowess not just from 'boom swinging' (I never used that) or stiff, short drivetrain (certainly a factor, but on a matter of 4-5 percent), but 'cockpit' that facilitate bar-pulling instead.

Unfortunately, I cannot afford something like Garmin Pedals and measure power 'in the field'.
Plus, how can I test it on a bent? Quickly lose 50 pounds and make new measurements? Not that I wouldn't like that, but that surely cannot happen overnight and too much other factors are going to be involved!

Cover the seat with the meat? That would take a LOT of meat, though doable...
Would, say, adding extra (soft) seat padding and comparing data be a meaningful test? I'll still need to find a material that about equals to human flesh in 'spring coefficient' and damping quality...

The bobbing up and down while pedaling was especially noticeable on the Bacchetta CA2, despite the relatively hard seat pad I had. I've noticed a lot of head bobbing when riding next to other bent riders, especially when they're pedaling hard. A higher cadence should limit that effect somewhat, but I haven't come up with a way to measure that. The M1 Thundervolt, which you see pictured in my avatar, has a very thin seat cover. It's only about 3 mm thick and very uncomfortable, but it was designed that way to minimize power losses. The upper portion of the seat also curves forward to hold your shoulders in place. All of this was done to make the M1 as efficient as possible, but you do pay a price in terms of comfort.

 

[Gary123]

I "feel" like shorter cranks reduce bobbing. No scientific testing but if legs are turning smaller circles may be less motion in hips. That was also on a bacchetta. On the vendetta I just crank and hang on.

 

[Jim Parker]

I use Rotor QXL rings and I've done quite well in racing in the 4-hour to 6-hour event range. While I have done quantitative testing with many aspects of my training. I switched to the Q-rings after a brief subjective trial. I just felt like I was going as fast as I was with round rings, but with less fatigue. Maybe a psychological benefit? It doesn't really matter. A benefit is a benefit. I tend to be a masher. Some people have more efficient muscle contractions at a slower pedal speed. I think that's me. Short cranks and a slower cadence give slower pedal speed. I'm using 165mm cranks now, but might go shorter, and I'm 6'2". I suspect Q-rings have no benefit for some people.

I agree the state of bicycle science is incredibly shabby. Now that we have thousands of cyclists with power meters on Strava, wouldn't it be cool to have Strava coordinate randomized controlled trials? We could finally answer these questions. Give premium membership benefits to people who volunteer to be assigned to test equipment. There is so much data now, but it is not being used very effectively.

 

[Osiris]

I "feel" like shorter cranks reduce bobbing. No scientific testing but if legs are turning smaller circles may be less motion in hips. That was also on a bacchetta. On the vendetta I just crank and hang on.

There have been times when I've been on the trainer and I just wanted to see how fast I could turn the pedals. I've seen a video of an Olympic sprinter pedaling at 300 rpm on rollers, but by the time I hit 130 rpm, I can no longer pedal smoothly. My fastest cadence while riding was 152 rpm (last Sunday), and it seemed as if I was about to shake myself right off the saddle. Pedaling more slowly (80-85 rpm) causes much less bobbing even at very high power outputs because the slower movements make it easier to concentrate on smoothing out the pedal stroke. But on very steep climbs, where I'm struggling just to keep the bike moving forward at low rpm's, there will be a lot of unwanted body movement.

 

[Balor]

Funny thing is, you can bob all you like on DF - pedal pressure going to remain constant (your weight), so you are free to do all kinds of movements that are relevant to saving one's knees for instance (like 'jump on top of pedals' that I do and pedal with legs nearly straight all the way during high-power, low cadence efforts). It will cost you efficiency, of course, but not POWER. Rocking the bike will actually increase it for a further decrease in efficiency.
Not so with bracing against the seat, unfortunately.
Among my crazier ideas was using a 'sliding seat' that is connected to a spring to replicate gravity in a way. Unfortunately, springs in series simply add up and any losses that happen in your body tissues and padding will still happen, and I'm not sure at all that spring can replicate gravity that does NOT work like a spring at all, but provide uniform acceleration of 9.8 m/s*s, and it is quite challenging technically, so I've never done it.

The bobbing up and down while pedaling was especially noticeable on the Bacchetta CA2, despite the relatively hard seat pad I had. I've noticed a lot of head bobbing when riding next to other bent riders, especially when they're pedaling hard. A higher cadence should limit that effect somewhat, but I haven't come up with a way to measure that. The M1 Thundervolt, which you see pictured in my avatar, has a very thin seat cover. It's only about 3 mm thick and very uncomfortable, but it was designed that way to minimize power losses. The upper portion of the seat also curves forward to hold your shoulders in place. All of this was done to make the M1 as efficient as possible, but you do pay a price in terms of comfort.

That is why I want to experiment with "shoulder boosters". A combination of low recline and low BB makes one's 'bracing vector' run parallel to the seat (unfortunately, it also make pulling on relatively high bars not very effective in my case, and my Thor glass fiber seat is VERY flexy in upper portion, making 'bridging' not very effective as well) - pretty much like on 'horizontal' hour record highracers.
This way you can have even a hammock-like mesh seat, but very effective bracing with your shoulders that are quite bony even on my obese frame. I'm not sure at all it will work (as in - not be horribly uncomfortable) for longer rides, but I'll see I guess.

 

[ed72]

I did not measure any benefit with Q-Rings and sold them. Zippo. I did get a slight benefit with QXL with tweaking of the settings.

Important to distinguish between the two elliptical models of Rotor rings. The Q-Ring is mildly elliptical compared to the QXL, which is less radical than the Osymetric rings or the German Power rings (10, 16, 20, and 25 ovality apprx., respectively)

Cadence and power matter. The link I posted has a model and simulator to see or get a feel for the differences in power but more importantly, the difference in forces between round and elliptical rings.

Q Rings are almost round. QXL rings are more "oval". Important to distinguish.

 

[ed72]

Funny thing is, you can bob all you like on DF - pedal pressure going to remain constant (your weight), so you are free to do all kinds of movements that are relevant to saving one's knees for instance (like 'jump on top of pedals' that I do and pedal with legs nearly straight all the way during high-power, low cadence efforts). It will cost you efficiency, of course, but not POWER. Rocking the bike will actually increase it for a further decrease in efficiency.
Not so with bracing against the seat, unfortunately.
Among my crazier ideas was using a 'sliding seat' that is connected to a spring to replicate gravity in a way. Unfortunately, springs in series simply add up and any losses that happen in your body tissues and padding will still happen, and I'm not sure at all that spring can replicate gravity that does NOT work like a spring at all, but provide uniform acceleration of 9.8 m/s*s, and it is quite challenging technically, so I've never done it.



That is why I want to experiment with "shoulder boosters". A combination of low recline and low BB makes one's 'bracing vector' run parallel to the seat (unfortunately, it also make pulling on relatively high bars not very effective in my case, and my Thor glass fiber seat is VERY flexy in upper portion, making 'bridging' not very effective as well) - pretty much like on 'horizontal' hour record highracers.
This way you can have even a hammock-like mesh seat, but very effective bracing with your shoulders that are quite bony even on my obese frame. I'm not sure at all it will work (as in - not be horribly uncomfortable) for longer rides, but I'll see I guess.

Lose the fat for sure.

I have have gained nearly 25% on my FTP and chopped over 3 minutes off my 10 mi TT since thinking deeply about and applying what Bob wrote, 3+ months ago. Unfortunately, I will never be able to churn out 400+ watts for 5 minutes like you (yes, I am jealous) but if I get to my old 350-360 watts on a DF, I'll be happy. Much of that thread is next to worthless. What I could write would only be a major pain, but if you allow me, please think about your seat more to support efficient respiration and perfusion than a bucket to minimize your power robbing fat although I do not mean this to say a mesh seat, big squishy pads, or the lousy fiberglass seats are efficient WRT power transfer, how you use your shoulders, torso, lumbar, and sacrum greatly impacts my respiratory system. Maybe not yours. YMMV. N = 1. No publishable data to share. No appeal to authority. Then again, I haven't found many good studies.....

http://www.bentrideronline.com/messageboard/showpost.php?p=1536957&postcount=67