There have been lots and lots of threads re: oval chainrings, do they work, what do they do, etc., including this thread, but I would like to pose the very specific question of:
Can we develop a test protocol that will tell us if oval chainrings work for any particular cyclist?
Let’s say that someone assembled the following tools. Would this be sufficient to conduct a test, and if so, what would the protocol be?
Pioneer powermeter. (I would think the force vector metrics would be useful in determining where the cyclist might have “weak spots” in the pedal stroke that either are or are not helped/hindered with the oval rings - this Slowtwitch article seems to indicate that at least one cyclist found this type of analysis helpful - in particular, this statement: “Through ongoing analysis and instant feedback during the fit adjustment, I was able to instantly improve pedalling efficiency (1% increase) and improve my L/R power balance. These minor improvements resulted in an immediate increase in power (nearly 5%) in my 1 min, 3 min, 5 min, and 20 min peak power (N=1)”).Round and oval chainrings. This one should be obvious.KICKR or PowerTap wheel. Just in case that switching from the round to oval rings causes the slope of the Pioneer powermeter to change, we can make an apples-to-apples power comparison between the round and oval rings by measuring power downstream at the wheel.Heart rate monitor. I am actually fairly dubious of this one, as I personally find my HR to vary for all sorts of reasons that don’t always coincide with effort. But I throw this out here since it is a common way of measuring the effort put in by the body in order to make a given level of power.BSXInsight blood lactate measurement device. Ray did a pre-review here. It would seem that this data could potentially be more valuable/differently valuable than HR data in determining the tax on the body in generating a given power output.Data collection devices. I would think we could want the same unit to collect data from the same powermeters. Will something like a Garmin 500 work? Is there a “best” head unit for this test?
Can this be made to work and if so, how would you go about the test?
KICKR or PowerTap wheel. Just in case that switching from the round to oval rings causes the slope of the Pioneer powermeter to change, we can make an apples-to-apples power comparison between the round and oval rings by measuring power downstream at the wheel.
This is the most critical point. If you search around you can find some posts from me where I experienced a big power gain (at least as the SRM measured it) with Osymetric rings. But when I used a powertap, the gain evaporated. The bottom line was that the SRM loses accuracy when pedal velocity is variable.
I am not a scientist and have a low attention span so I am not sure I am picking up everything that went into that study, but from my Clif Notes skim of the research paper, it seems that they measured performance over time to see if performance increased with oval rings rather than round. As people have pointed out, there could be all sorts of reasons why that occurred (adaptation to oval pedaling, etc) so (i) we are really inferring efficacy of the oval chainrings from performance over time, and (ii) it is a study of a sample population in order to draw general conclusions.
What I am interested in is (i) not an inference derived from measurements over time, but rather an A/B comparison at any one time of the power output difference with round and oval rings while maintaining the same metabolic cost by the body and (ii) finding out what works best for an individual rider, not a sample of riders.
I ride Q-rings, but I don’t see anything in that study which indicates that they are better. Perhaps the 1-2 second gain in the 1km TT but you will get variability with that across a broad range of athletes after a sub max graded test.
The study is very interesting even if there’s just a placebo effect. Q-rings allow me to stay in the aero position for longer stretches at higher powers. Definitely quantifiable, but not as I was doing it when I wrote that post. And even if placebo, that effect is worth it to me.
The study is very interesting even if there’s just a placebo effect. Q-rings allow me to stay in the aero position for longer stretches at higher powers. Definitely quantifiable, but not as I was doing it when I wrote that post. And even if placebo, that effect is worth it to me.
From what can tell it loads up my legs with less torque at the top of the pedal stroke when my glutes and quads are at their longest length and therefore weakest position. It then allows me to pass through that phase at higher velocity and lower force so I can deliver a higher torque when my leg is in a less compromised position. At the top of the pedal stroke you have to react the muscle stretch, forward push and backward pull with trunk muscles which over time can get fatigued and start to ache. It’s not a lot of reaction they have to resist, but it adds up over time, especially at higher powers. I think every cyclist has experienced a back ache on a long ride and given I have lopsided hips, it’s especially pronounced for me.
Maybe it isn’t that simple. A couple people seemed to hit on the comfort in the weak spot. When you mention comfort, you are talking about a personal thing.
Going somewhere it is more tangible.
Office chair, if my office chair sucks, I’m going to keep standing up.
Rifle shooting, having a good cheek rest will improve your shot greatly, especially at longer distances. Some people aren’t comfortable resting their face on bare wood or fiberglass. Maybe they want a padded cheek rest. It isn’t the item itself that makes you better in these cases, it is that they allow you to be more comfortabe ALLOWING you to be better.
People have been trying for 100 years (serious) with no clear result that they work.
Verified by the Google patent database: http://www.google.ca/patents/US513589
.
The way I see it is to remove as much uncertainty as possible and increase the repeatability to make it as reliable as possible. People are too unreliable to exert exactly the same amount of effort in a controlled situation in back to back tests.
A mechanical means to reproduce the same effort 999/1000 times is what I would try to design for a test setup (a gear system to drive the pedals with a motor that can produce constant power and vary the RPM/Cadence). Strain gauges everywhere (crank arms - both sides, around the embedded in the chainrings, around the spider, rear hub based like the CycleOps one, wheel based like a car dyno). You try to measure drive train losses with a controlled reference point to validate results.
Not easy and not cheap but you take out a lot of variables like sample size and the people factor (maybe after 4 weeks of using the rings they both adjusted to the rings and gained fitness…that skews the results and doesn’t help validate a test…it increases the uncertainty). Just thoughts that go through my head. I work for a testing lab and we have to deal with uncertainty and repeatability all the time.
If you are more comfortable and don’t make more power, then I care very little.
I’ve done my own N=1 experiment with them myself, with powertap, for a whole season.
Didn’t seem to do anything.
Maybe it isn’t that simple. A couple people seemed to hit on the comfort in the weak spot. When you mention comfort, you are talking about a personal thing.
Going somewhere it is more tangible.
Office chair, if my office chair sucks, I’m going to keep standing up.
Rifle shooting, having a good cheek rest will improve your shot greatly, especially at longer distances. Some people aren’t comfortable resting their face on bare wood or fiberglass. Maybe they want a padded cheek rest. It isn’t the item itself that makes you better in these cases, it is that they allow you to be more comfortabe ALLOWING you to be better.
per Mr Mott "I’ve done my own N=1 experiment with them myself, with powertap, for a whole season.
Didn’t seem to do anything. "
I guess if the question of is it better then you are probably right, the other question is it any worse? I have been hoping to try them for my own n=1 trial, and have a friend who rides them but who knows if they help him or not. The big question is if they do no harm and could potentially in principle be beneficial than what is the problem. But if they affect the mechanics of the shifting or in some way negatively affect the ride then they are not good and should be avoided.
People have been trying for 100 years (serious) with no clear result that they work.
Verified by the Google patent database: http://www.google.ca/patents/US513589
Mr. Metz should have patented that goofy seat in his drawings, too.
People have been trying for 100 years (serious) with no clear result that they work.
Yes, for over 120 years they have been trying to compensate for the inability to apply effective torque in the dead spot sector 11-1 o’c. Before Q-rings, Rotor tried the Rotorcrank idea. In both cases the objective is almost the same, speeding up the crank through the idling leg sector and slowing it down through the power sector 1-5 o’c. Rotorcranks worked by changing the crank mechanism for use with the round chain ring, Q-rings work by changing the shape of the chain ring for use with standard cranks. If you were to combine both these ideas, would you double the advantage and make verification a much easier task.
People have been trying for 100 years (serious) with no clear result that they work.
Verified by the Google patent database: http://www.google.ca/patents/US513589
Mr. Metz should have patented that goofy seat in his drawings, too.