Q ring upgrade - Ahhhhhhhhhhhhh......

ratz

Wielder of the Rubber Mallet
It is was "really" true and verifiable - then EVERYBODY on the TOUR would be riding them - and they are not... so what does that tell you?

hmmmm I hear that a lot, especially from smart people on bike related tech shows (most of who then say; but I ride them myself personally because I like them) ...... What It tells me is the teams have sponsors; that supply parts for free; mechanics are set in their ways; and most riders couldn't tune there derailleurs to to save their own lives. Being fast does not make one a good wrench, in fact it is usually the opposite :confused:.

Chain drop problems with elliptical are probably the one thing keeping them off more bikes as it frustrates mechanics that get the blame for a bad setup from the riders that don't know how to properly shift. Their are people that refuse to run Di2 because they can't manage to keep the battery charged for race day..... people are an entertaining lot in general.

Anyhow In racing you don't ride the best stuff; you ride the best stuff you are given by you sponsors (often training on crap back home depending on the team). A small number of riders do have the clout to override the sponsors and do in-fact ride Rotor's and Osemetric, but they are forced to paint over the logos on them by their sponsors; Specialized was notorious for making people paint over Quark crank power meters a few years ago and put fake s-works logos on them. This happen when they really started to pimp the S-works line up; it's pretty well documented on velonews and other publications. Yes I watched each day of the Tour de France twice I probably follow this too closely. Bring on the Vuelta.

Ride what you like is my theory; and really don't try and extrapolate from DF to Recumbent; the leg muscles aren't the same; why would the same tech work the same way between the platforms.

I'm far more interested in what people that spend their own money on choose for their bike; and what they buy multiple times over. The pro's don't ride < 165 mm cranks; is that because they are tall, because it doesn't work; or because they don't know....not sure it matters to me, I'm more apt to say hmmmm short cranks work for Larry and TT bike people; must be something to it for them.

footnote: Short cranks and Oval rings do the same general thing; when you combine them you get less effect from both; I love all the test data but I'm not sure testing Ovals with 140mm cranks will give measurable changes over rounds. Testing them with 170mm cranks would be more interesting. Says the guy riding 155mm cranks instead of 165mm because of Larry's test data.:p
 

super slim

Zen MBB Master
Of the 22 teams at Tour De France, ALL had electric shifters, 2 had ETap, 17 Di2, and 3 Campy.
There were a LOT of FSA cranksets!
 

ratz

Wielder of the Rubber Mallet
Of the 22 teams at Tour De France, ALL had electric shifters, 2 had ETap, 17 Di2, and 3 Campy.
There were a LOT of FSA cranksets!
I missed that one; I figured 50/50. mech/electric; but I certainly can see why;
 

LarryOz

Cruzeum Curator & Sigma Wrangler
Are we going to see some tests by Larry of OCP1 and OCP4 settings?
Run each one at 80% max. power for 1 hr, then see how long and far you can go at 105% power???
Any better ideas, of how to test?
Wow - that would be quite a workout - and I think you have a really good idea here to follow.
I'll have to ponder if riding that hard in the first set would negatively affect the second set due to fatigue.
There also might be another way to test what you have proposed Slim - stay tuned...
 

RojoRacing

Donut Powered Wise-guy
Is there a general consensus to oval rings and power meters? I hear the unless your on a rotor brand power meter they end up reading a few % high or low.
 

super slim

Zen MBB Master
Wow - that would be quite a workout - and I think you have a really good idea here to follow.
I'll have to ponder if riding that hard in the first set would negatively affect the second set due to fatigue.
There also might be another way to test what you have proposed Slim - stay tuned...
I assumed there would be a 30 minute rest period between sets!!!!
Is that enough time to recover???
 

ratz

Wielder of the Rubber Mallet
Is there a general consensus to oval rings and power meters? I hear the unless your on a rotor brand power meter they end up reading a few % high or low.

It's finally getting clearer on that front.

To be perfectly accurate and agnostic you need a wheel sensor. To be really close you need something that takes multiple measurements sufficient to remove the angular momentum changes inherrient in the oval rings.

The ones that claim to work are: Stages, Powe2Max and PowerTap P1 pedals, and Rotor.
The ones that don't work are: Vector v1, Quarq, PowerTap C1 crank, Panisonic, SRM.
The jury is out on the Vector V2.

Stages measures 1 time per rotation. Power2Max and P1 measure 100's of times per rotation, Both techniques work mathematically.
The rest either measure too infrequently or they want nothing to do with the debate so they bow out.

Given an Erg Trainer like the Kickr; set the erg resistance to XXX
Pedal round and oval ring and compare the power you have to put in on the pedals to hold XXX on the Erg.
The kickr heavily smooths it's data in erg mode to be something between 5-10 seconds. So look at you input power at 3s, 5s, and 10s smooth for comparison.
That's really the simplest test, but I suspect you'll find that's not enough precision to tell a difference, so you are left with perceived exertion.
Fly wheel inertia matters too; a small gear the turns the fly wheel slowly will give a better test than one the spin it fast and wipes out micro accelerations caused by uneven pedally.
 

JOSEPHWEISSERT

Zen MBB Master
footnote: Short cranks and Oval rings do the same general thing; when you combine them you get less effect from both; I love all the test data but I'm not sure testing Ovals with 140mm cranks will give measurable changes over rounds. Testing them with 170mm cranks would be more interesting. Says the guy riding 155mm cranks instead of 165mm because of Larry's test data.:p
Ratz, I (somewhat) disagree. I've been thinking about this and trying to imagine how it all works. Someday, if I have time, an accurate mathematical model would prove it once and for all (any math nerd volunteers?). The main benefit of short crank arms is to eliminate the extreme bend of the knee, thereby preventing damage to the knee. By eliminating the extreme bend, the least mechanically advantageous part of the leg stroke is eliminated. This elimination is where I agree with you that the short cranks and non-round rings have a similar purpose. But the stroke, with short cranks and round rings, is still not optimal. The non-round rings act on the remaining stroke to optimize it, in addition to the effect of short cranks, but not in the same manner. So they are complementary, working together to achieve one desired effect. The rings pick up where the cranks leave off. Ideally, the rings work by leveling the mechanical advantage of the quads et al in the kinetic chain so that the system output (i.e., torque) is the same throughout the leg stroke. In other words, the legs should be able to put out the same twisting force of the drive wheel regardless of any given leg stroke position. This is accomplished by combining the mechanical advantage of three things: leg stroke, crank arm angle, and chainring diameter. The non-round chainring diameter acts like a continuously variable gearing to compensate for the imperfect result of combining leg stroke and crank arm angle. So the specific chain ring design could be calculated exactly by knowing the sum of the leg stroke and crank angle mechanical advantages. The design could be tested in two ways. First, objectively, the torque could be measured to verify that it is level, meaning that it remains the same throughout the entire pedal stroke. Second, subjectively, it should feel smooth, as though the legs are putting out the same torque throughout the entire pedal stroke. Caveat: the necessary ring design might not be mechanically feasible, thereby requiring some compromise in the desired effect. Also, as you and I discussed many months ago regarding ring tuning, the design will be somewhat compromised by the effect of any specific cogset gear diameter on the point of tangency on the chain ring. Which means that shifting from one cog to another will change the effect of any non-round ring design.

Bottom line: short cranks and non-round rings are complementary. The optimal ring design should be easy to calculate for any one individual, who would have specific leg geometry. Tuning the non-round rings would not be necessary because the ring position would be determined as part of the ring design (assuming one cog diameter). And the resulting effect should be easy to test by simple measurement. I envision a simple program where a person's data are put in, and an optimal chain ring design and position are put out. Then we could put this argument to bed once and for all. :D
 

MrSteve

Zen MBB Master
Wait a second:

Using shorter crank arms means that your feet are spinning smaller-diameter circles through the air.
Less turbulence is generated up front with short crank arms than is generated with long crank arms.

Sorry.
Continue!
 

ratz

Wielder of the Rubber Mallet
Joe, I was probably being a bit too shorthand. I agree with the more in depth thoughts you posted. My simpler point was that short crank arms reduce the time and size of the dead spot by virtue of the smaller diameter. Ovals meanwhile reduce the effort in the dead spot. Both lower the strain on the legs and lead to better long term power conservation. High rpms also does this somewhat.

So When Larry tests these on his 10mm cranks oops I mean his 140mm cranks (we are not suppose to talk about the 10mm ones). These tests conducted at 100rpm show not much difference between round and oval. My hypothesis is that the cranks are so short and the rpms so uniquely high that the difference between round and oval are smaller than the error % in the simple on the road testing apparatus.

So this becomes one of the rare cases I go with what the math says and what precieved exertion tells me, because I think that is the best test we can currently afford. I do know this, with a 34round/32 I can't climb the biggest high around here. But with 36qxl/30 I climbed much bigger in Portland, but that might have also been not wanting Larry to beat me to the top. Helps that he was on a loaner bike and I was not.

Most of my thoughts are not original on this topic they come from talking to Mark Stonach at bikesmithdesign about what his experience with TT athletes has taught him. He'll tell you the you can use either short cranks or qrings, but on a recumbent when possible combine them. Unfortunately that's far too long a conversation to recount and once again purely subjective
 
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LarryOz

Cruzeum Curator & Sigma Wrangler
So When Larry tests these on his 10mm cranks oops I mean his 140mm cranks (we are suppose to talk about the 10mm ones). These tests conducted at 100rpm show not much difference between round and oval. My hypothesis is that the cranks are so short and the rpms so uniquely high that the difference between round and oval are smaller than the error % in the simple on the road testing apparatus.
This is right on target with my testing and my perceived "effort", and perceived "differences" when switching back and forth from round to Q-rings. I even did some testing riding at 110 and 120 rpms as well, and truthfully when pedaling that fast, there is really no noticeable difference as long as the power is in a reasonable range: Say <250 watts. However as the power increases past that point I think that Q-rings (and shorter cranks) offer even greater advantages. This is especially true for climbing.
 

LarryOz

Cruzeum Curator & Sigma Wrangler
I do know this, with a 34round/32 I can't climb the biggest high around here. But with 36qxl/30 I climb much bigger in Portland, but that might have also been not wanting Larry to bet me to the top. Helps that he was on a loaner bike and I was not.
Ratz, I think you are pretty much the KING of Power (KOP) on a Cruzbike; any Cruzbike. Loner or no loner - I don't think I can ever match you up a hill unless your chain drops, or I distract you in some way! :eek: - But that doesn't mean I won't keep trying!:p:);)
 

RojoRacing

Donut Powered Wise-guy
Ratz, I think you are pretty much the KING of Power (KOP) on a Cruzbike; any Cruzbike. Loner or no loner - I don't think I can ever match you up a hill unless your chain drops, or I distract you in some way! :eek: - But that doesn't mean I won't keep trying!:p:);)

I like them Goals.

My QXL was just dropped off but I'm in the middle of a spin trainer session so I'll start looking at it this evening. I'm probably going to ask a few question about the install because last time I studied the instructions it seemed very confusing. I'll read through them again as well as this threads earlier pages and do my best first.
 

ratz

Wielder of the Rubber Mallet
If you same a picture of your drive side crank in the dead spot we can annotate it in two minutes and send it back to you. :)
 

RojoRacing

Donut Powered Wise-guy
C9F24A34-A064-478C-9A8E-BA3EE8EC2AD5_zpswqoeqvr3.jpg
83742043-8ECE-4E30-BCCD-B340E70B8D0F_zpsbfum0wnu.jpg
 

RojoRacing

Donut Powered Wise-guy
When we setup the ring with the chain across the top looking for that position #1 what cog are we supposed to be in? I don't see it mentioned in the instructions. I'm kind of thinking middle cog as an average or the large cog for some kind of other reason I'm not thinking of.
 

RojoRacing

Donut Powered Wise-guy
Ok so I understand the whole dead spot and #1 thing and I'm going with the middle cog for now unless told otherwise. Here's the problem I just ran into, I can't put the #1 mark at the first chain roller fully engaged because it would land on the unusable section between my 2 hole and 3 holes pattern found on only the 110BCD rings.

Here is a pic of the ring mounted and the right crank arm at dead spot.
64D6A6BB-03C9-436F-9D23-2BF66FAC5A3E_zpsng2mtozk.jpg


Notice the #5 lines up with the first roller perfectly but if I jump the ring 2 teeth forward I'll land in between shown in this second pic.
E0E1DE8D-B85F-4677-83A6-EE675F07058A_zpsdvhvm0wn.jpg
 

ratz

Wielder of the Rubber Mallet
Oh goodie the Hidden bolt behind the crank those are the hard ones to do... but no matter...
Let's see if the factory 1-5 mark will work or if you will have to use offsets from them. So...

1) Try mounting #2 right on the bolt in the red square.
(you can skip the hidden bolt until we are sure so you don't have to futz with it if you need to rotate the ring)

2) Once mounted, Then find the TALLEST Tooth on the ring and position that Tallest tooth at the yellow square; by the derailleur, that should be the tooth the first full chain roller engaged.

3) Check the Crank position when tallest is in yellow box; one of the arms should be about 60-65% of the way through the power stroke (about where you thumb is). when the tallest tooth engages.IF that is the case you can use the RED Square Bolt and the factory marks.

Post picture at that point... for verification.
IF you can use the factory marks you'll probably to test OCP#2 and OCP4 mounted to that bolt; I suspect you'll like #4.


IF not we need to rotate the ring until it's true; are then mark new relative 1,2,3,4,5 holes. Black sharpie works well so people can't tell.

The keep point here is the factory marks are setup 1-5 to allign on a DF on the hidden bolt behind the arm. On the recumbent we need to see if any of those factory marks align correctly with an one of your crank arms. If they don't then we need to make 5 ghetto marks are different holes that do align to a bolt; that was you can quickly adjust between the 5 working positions without having to constantly re-find the tallest tooth and the 65% power position.


C9F24A34-A064-478C-9A8E-BA3EE8EC2AD5_zpswqoeqvr3.jpg
 

JOSEPHWEISSERT

Zen MBB Master
Joe, I was probably being a bit too shorthand. I agree with the more in depth thoughts you posted. My simpler point was that short crank arms reduce the time and size of the dead spot by virtue of the smaller diameter. Ovals meanwhile reduce the effort in the dead spot. Both lower the strain on the legs and lead to better long term power conservation. High rpms also does this somewhat.

So When Larry tests these on his 10mm cranks oops I mean his 140mm cranks (we are suppose to talk about the 10mm ones). These tests conducted at 100rpm show not much difference between round and oval. My hypothesis is that the cranks are so short and the rpms so uniquely high that the difference between round and oval are smaller than the error % in the simple on the road testing apparatus.

So this becomes one of the rare cases I go with what the math says and what precieved exertion tells me, because I think that is the best test we can currently afford. I do know this, with a 34round/32 I can't climb the biggest high around here. But with 36qxl/30 I climb much bigger in Portland, but that might have also been not wanting Larry to bet me to the top. Helps that he was on a loaner bike and I was not.

Most of my thoughts are not original on this topic they come from talking to Mark Stonach at bikesmithdesign about what his experience with TT athletes has taught him. He'll tell you the you can use either short cranks or qrings, but on a recumbent when possible combine them. Unfortunately that's far too long a conversation to recount and once again purely subjective
Ratz,

In trying to get to the bottom of the non-round chainring effect, here are some additional thoughts. I have to think this through by writing it out. And some thought experiments may also be required. This is rather lengthy, so schedule some vacation time now before you continue.

You said, "short crank arms reduce the time and size of the dead spot by virtue of the smaller diameter". My understanding of this claim is that the knee angle does not go below (approximately) 90 degrees. Therefore, the "dead spot" is consequently reduced by allowing the leg to extend from a more powerful (more advantageous) position. For example, the leg extension may start at 90 degrees instead of 75 degrees, resulting in more time spent in a powerful extension. This is because the "downtime" of the quads and related muscles would be reduced. Which means that less time would be spent in the "dead spot". It appears we agree on this point.

You said, "Ovals meanwhile reduce the effort in the dead spot". My understanding of this claim is that an oval chain ring would compensate for the non-level mechanical advantage as the leg extends from beginning (around 90 degrees) to full extension (around 170 degrees). The non-level mechanical advantage is a sum of the two things. First, the leg's mechanical advantage changes from minimum to maximum as it travels from most bent to least bent. This can be demonstrated, by the way, by performing squats with a barbell on one's shoulders. Squatting to a leg angle of 170 degrees allows one to lift more weight than squatting to a leg angle of 90 degrees. I don't know if a graph of this would be a straight line or if it would be curved (convex or concave). But it seems to be roughly linear at least. Second, the crank arm (of any length) travels through one-half of a revolution as one leg extends from minimum to maximum extension. At minimum extension (the leg is bent the most), the force on the pedal is directly into the crank (parallel to the crank), so that the resulting torque is zero, which means that the crank rotation is purely from momentum (and possibly pulling up) at this point. As the crank arm rotates for the next 90 degrees, the mechanical advantage of any force applied to the crank arm changes from zero percent at parallel to 100% at perpendicular. And, due to trigonometry, the mechanical advantage changes in the form of a sine wave. As the crank arm rotates from 90 degrees to 180 degrees, the mechanical advantage is reversed in the form of a sine wave from 100% at perpendicular (half extension of the leg) to zero percent at parallel (full extension of the leg). So, there are two mechanical advantages that can be graphed as 1) a line going from lower left to upper right in a roughly-straight line for the full leg extension; and 2) a sine wave starting at the lower left, maxing out at the halfway point in the extension, and dropping back to zero at the right side of the graph. If we draw a graph of the sum of the two mechanical advantages, we should see the first half as roughly linear and increasing from lower left to upper right. But at the halfway point we see one line is going up and the other is going down. If they cancel each other out, we see that the second half of the leg extension is roughly horizontal, which means that the muscle fiber activation is roughly consistent throughout the entire second half of the leg stroke. So it's the first half of the leg extension that needs help. This is where a non-round ring should help out by leveling out the mechanical advantage of the first half of the leg extension. A non-round ring would do this by changing the diameter of the chain ring, as if it were a continuously variable transmission. It appears that we agree on this point also.

Speaking of muscle fiber activation, this raises a question of purpose. What are we trying to accomplish with non-round chain rings? One answer would be more power. But what does that mean? To get the same drive wheel torque in the first half of the leg extension as in the second half, the leg muscle would have to work harder (activating more muscle fibers). This imbalance can be thought of on a scale, but it could entail activating too many muscle fibers in the first half and just the right amount in the second half. Or it could mean activating just the right amount in the first half and too few in the second half. Or it could mean consistent muscle fiber activation throughout the entire leg extension by sacrificing smooth drive wheel torque, and thereby wasting energy (this is probably a less common option). It seems that, for maximum efficiency, we would want to maintain our drive wheel torque, but even more importantly, we would want to keep our muscle fiber activation consistent throughout the entire leg extension. This way, we can conserve our limited glycogen stores as much as possible, which means that we can get more energy aerobically from fat. Which means we can get the same amount of driving power for a longer time. So maybe non-round rings allow us to be more efficient in a physiological sense, which translates to a given power output for a longer time (as opposed to getting a higher power output for a shorter time). The reason efficiency is important is because power output will drop when glycogen stores are depleted. So keeping a level mechanical advantage throughout the entire leg extension allows a consistently level muscle fiber activation, which yields the maximum power output over a long time (such as hours). But what about hills? The same effect would be present. It's just that the (primarily) anaerobic power output would be most efficient, thereby using up less glycogen than with round rings. Keep in mind that aerobic and anaerobic power output is a sliding scale, where power output becomes more anaerobic (and less aerobic) as the power output increases. In a highly trained muscle, the aerobic power output can be higher than for a lesser trained muscle. But at higher power outputs, the highly trained muscle will still burn glycogen like a wild fire. The difference is that the highly trained muscle will buffer the hydrogen ions (not lactic acid as is commonly misunderstood!) (thereby limiting the burning sensation) and allow the anaerobic power output to continue, whereas a lesser trained muscle will fail at some point (power output drops, as much as all the way to zero) until it recovers. Athletes with highly trained muscles have the advantage of staying more aerobic at any given power level, thereby conserving even more glycogen. So any athlete would benefit from a more efficient power output and would also benefit with any given combination of aerobic and anaerobic power output. The bottom line is that non-round rings should, in theory, extend aerobic power output by getting more power from fat over a long distance as opposed to round rings, which would get less power over a long distance from fat. I say "long distance" because we all probably have enough glycogen to last a while, since we all ride a lot. This efficiency should also translate to better long distance race results.

How to measure the effect? If the given technology is having trouble measuring the effect of the drive wheel torque due to high rotational velocity of the pedals, cranks arms, bottom bracket, or drive wheel, then an experiment could be performed where the resistance to the drive wheel is increased enough to slow down the drive wheel rotation so that the drive wheel torque could be accurately measured. This would measure the output effectively, but then a method of measuring the input would also have to be devised. This would probably mean measuring oxygen in, carbon dioxide out, and force to the pedals throughout each pedal stroke. The graph of the force to the pedals should match the graph of the mechanical advantage of the leg stroke. That is, the force should increase linearly from least force to most force over the entire leg stroke as the mechanical advantage of the leg increases from least to most. That's assuming the muscle fiber activation remains the same throughout the stroke. (This would also give a measurement of the leg's mechanical advantage that could be compared to a calculated mechanical advantage.) If it were possible to measure the muscle fiber activation throughout the stroke, that would be very useful also. I don't know if that's possible. And then there is the drive wheel torque (the system output) which could easily be measured throughout the leg stroke. We would expect the drive wheel torque to be consistent throughout the leg extension, but would probably drop at the end of each stroke (which is the beginning of the next stroke). But most of the leg stroke should create a fairly level drive wheel torque. The bottom line on this system effect throughout the leg stroke is that the graph of the muscle fiber activation should match the graph of the drive wheel torque because internal components (mechanical advantages of leg angle, crank arm torque, and non-round chain ring) work together to create a fairly level graph of each. The consistent muscle fiber activation creates the benefit of physiological efficiency, thereby extending a given power output over time. The force to the pedals over time and the distance traveled (by the drive wheel on a roller) vs. the oxygen use and carbon dioxide production should tell us how efficient the non-round chain ring system is compared with a round chain ring system.

Small non-round chain ring? I remember that you suspected the small non-round chain ring would have a lesser effect than the large non-round chain ring. I think the effect would be identical as long as the shape and ratio of the two non-round rings are exactly the same. That is, only the size would change. Think of it this way. Traveling on a flat course at over 30 mph at 90 rpm on a given surface requires a certain power output. Lets assume we can measure the muscle fiber activation. Now, alternatively, lets travel up a hill with a given grade and surface at 7 mph and 90 rpm so that our power output is the same. Our muscle fiber activation should also be the same. If we measure the graph of our muscle fiber activation, it should also be level in both cases - in fact it should be identical. Why is this? Because the sum of the mechanical advantages (from leg angle, crank arm angle, and especially the chain ring ratio) is the same in both cases. We might be using a different cog, but if the small ring is tuned to a large cog so that the tangent is the same as the large ring with a small cog, then the specific cog in either case will make no difference. So what changed other than the ring size? The resistance changed from wind resistance at over 30 mph to gravity going uphill and lifting bike and body weight. Since the gravity creates greater resistance than the wind in this scenario, the speed has to change, and therefore the chain ring changes, but the legs can't tell the difference. To the legs, the mechanical advantages together allow a smooth muscle fiber activation in both cases and the same graph of force to the pedals over the leg extension. The bottom line here is that the small ring will create the same advantageous effect as the large ring, but it would be used for climbing instead of for all out speed.

The bottom line of this whole non-round chain ring issue is that non-round chain rings (both large and small) should create a beneficial and measurable systemic and physiological effect that will be advantageous for climbing, for speed, for long duration events, and for racing due to physiological efficiency. The trick is to determine the specific ring shape for a given person through math, and then prove it through measurement.
 
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