XQL Q-rings .vs. Reg Q-ring .vs. Circular Chain Rings

ratz

Wielder of the Rubber Mallet
Who else has done good sets of CdA / Crr measurements? I saw Jim Parker's post, his numbers were averaging around 0.26, (and he's a bit bigger than me (skinny) so maybe 0.246 is not so bad.

In less than perfect wind conditions, done in the dark.

Cd*A: 0.255
Cr*R: 0.00395

Cd*A is probably a touch high need to run a better test.
 
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super slim

Zen MBB Master
Larry can you use the bike on your indoor trainer with a power meter, and put a round 52 T and a Q Ring 52 T chain rings on the crank, so you can change on the rung while maintaining the same trainer power, speed, heart rate and see the different pedal power readings?
I think the chain will change between the two rings of similar size?????
 

ratz

Wielder of the Rubber Mallet
Bringing in some thoughts from discussions elsewhere.

Because of Larry's high power potential and normally high RPM I didn't find his results all that surprising.

He has been training himself to a vary high cadence on short cranks using gears that work well for that. The Q-Ring is designed to minimize the resistance in the deadspot. So if you project that out. Someone on 175mm cranks; mashing at 60-65rpm in a big gear is going to have a different experience than someone spinning at 90-100rpm on 150mm cranks in a middling gear.

I simply find that he's trained himself in a manner that the delta between round and oval rings is going to be quite small (not a bad thing at all). Larry has reached the point that a lot of other variables will come into dominance. The number one variable is going to be the MBB providing an inconsistent pedaling angle which is going to have a big affect on the Vectors readings at the 3s range (30s average is probably less impacted). Only placing the bike on a stationary trainer is going to remove that problem. A kickr is probably the better place to do the test. Direct power mode at least will say; this cadence produced this power in this gear. At that point "perceived effort" data is probably very interesting, maybe even more so than HR data. It still not going to be complete because of the variability of the engine (o2 in and out; calories burned etc etc). but that doesn't make it junk data; it's just not high precision. So about the best we can do is Maximal effort for 1 minute, produces X power, Y Speed, Z Cadence for Gear Ratio B. If we had the data for multiple runs we could use comparative reduction (oh lord I'll have to get my diffy-q, and linear algebra books out) to make a graph with error ratios for the non-controled "perceive max effort" Yeah it won't be perfect but it would provide trend lines that could be compared. BUT and big BUT perceived effort makes these very "personal" results. Is it worth all the effort? Sure if it's "fun" and it was a rainy day. The only real way to test this would be to use a motor to turn the chain ring and measure in versus out. I'm sure Rotor has done that; and they don't publish the result.... I wonder why? no no I don't really wonder why.

As someone that only turns out 90rpm steady under perfect conditions riding on the nut, heres what I know subjectively. Going up hill at full effort (See larry I didn't say 110%) I have gears left with the Q-Ring and I don't with a Round ring. Mashing at 60rpm I can get more power out of my wimpy legs for just a bit longer. Those are both good; but the subjective part is the big one; my knees feel better after 80miles every time; and sometimes the subjective gains are all that matter. If you think you are faster wearing purple and it doesn't infact make you slower; then wear purple.

As for the pro's not using them; they complicate shifting smoothness and bike intechagability; and when you are training daily, spinning at high rpm; throwing out massive power; and using whatever form of epo or blood transfusions of the day the qring probably has so little bang for the buck that nobody cares. If everyone road "pain-agua" then maybe they'd use them.

So Larry if you are having fun keep testing; you are still learning things; remember when the HR data was suddenly confusing / suspect when you first learned about power.
 
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LarryOz

Cruzeum Curator & Sigma Wrangler
ey Larry, how much difference to your CdA do you think the trispokes are compared to say your deep (are they 70 or 80mm) rims (how many spokes?)?
I have not done any CdA calculations yet (will try to do that with my data soon). All I know is that the 3 spoke CF wheels use almost the same power to achieve the same speed as my 88mm CF rims (with Cruzbike Vendettta graphic), with same tires and tubes, etc. Very close!

Thanks everyone else for their replies, thoughts, etc. We are all learning here.
 

jond

Zen MBB Master
Bringing in some thoughts from discussions elsewhere.

Because of Larry's high power potential and normally high RPM I didn't find his results all that surprising.

He has been training himself to a vary high cadence on short cranks using gears that work well for that. The Q-Ring is designed to minimize the resistance in the deadspot. So if you project that out. Someone on 175mm cranks; mashing at 60-65rpm in a big gear is going to have a different experience than someone spinning at 90-100rpm on 150mm cranks in a middling gear.

I simply find that he's trained himself in a manner that the delta between round and oval rings is going to be quite small (not a bad thing at all). Larry has reached the point that a lot of other variables will come into dominance. The number one variable is going to be the MBB providing an inconsistent pedaling angle which is going to have a big affect on the Vectors readings at the 3s range (30s average is probably less impacted). Only placing the bike on a stationary trainer is going to remove that problem. A kickr is probably the better place to do the test. Direct power mode at least will say; this cadence produced this power in this gear. At that point "perceived effort" data is probably very interesting, maybe even more so than HR data. It still not going to be complete because of the variability of the engine (o2 in and out; calories burned etc etc). but that doesn't make it junk data; it's just not high precision. So about the best we can do is Maximal effort for 1 minute, produces X power, Y Speed, Z Cadence for Gear Ratio B. If we had the data for multiple runs we could use comparative reduction (oh lord I'll have to get my diffy-q, and linear algebra books out) to make a graph with error ratios for the non-controled "perceive max effort" Yeah it won't be perfect but it would provide trend lines that could be compared. BUT and big BUT perceived effort makes these very "personal" results. Is it worth all the effort? Sure if it's "fun" and it was a rainy day. The only real way to test this would be to use a motor to turn the chain ring and measure in versus out. I'm sure Rotor has done that; and they don't publish the result.... I wonder why? no no I don't really wonder why.

As someone that only turns out 90rpm steady under perfect conditions riding on the nut, heres what I know subjectively. Going up hill at full effort (See larry I didn't say 110%) I have gears left with the Q-Ring and I don't with a Round ring. Mashing at 60rpm I can get more power out of my wimpy legs for just a bit longer. Those are both good; but the subjective part is the big one; my knees feel better after 80miles every time; and sometimes the subjective gains are all that matter. If you think you are faster wearing purple and it doesn't infact make you slower; then wear purple.

As for the pro's not using them; they complicate shifting smoothness and bike intechagability; and when you are training daily, spinning at high rpm; throwing out massive power; and using whatever form of epo or blood transfusions of the day the qring probably has so little bang for the buck that nobody cares. If everyone road "pain-agua" then maybe they'd use them.

So Larry if you are having fun keep testing; you are still learning things; remember when the HR data was suddenly confusing / suspect when you first learned about power.

hi ratz and larry. ouch i sincerely had not intended to cause offence rather to try "help"possibly explain why the results are what they are.totally agree with what you say ratz. larry to make the effort to test is outstanding and shows dedication and is informative for us all and i greatly appreciate you sharing as you explore bike fit scientifically.not something i am able to do as i am not dedicated enough.i am mortified if i may have caused offence.

i do not think you can underestimate the subjective feel of your individual bike and bike fit a quarter inch here can really matter to your knees and the "feel" of the bike. once your bike feels right and is dialed in it is yours. make sure you mark that position :) the subjective gains are a big factor and indeed why we stick with it.if it feels right it is right and we are more of a chance to perform to our potential.
 

LarryOz

Cruzeum Curator & Sigma Wrangler
Jon the likelihood that you caused offense is about 0.001%. Various points of view drive the conversation.
Jon, I echo, echo, echo Ratz's statement. You already know you could never offend me my good friend! :)
 

KiwiGuy

Well-Known Member
Hi Larry

I'm very impressed by both the effort you made to undertake these measurements. and the thought you put in to ensure that in a real-world experiment run by one person you as much as possible reduced the changes to one variable. Well done!

I've been thinking about the results and the comments that people have made over the last couple of days. I believe your results are valid within the parameters of the extent of the testing you did. After some thought I can't accept that the placement of the power meter is going to have any effect on the result. You have nothing to apologise for. Just because the result isn't what was expected, doesn't mean that it is incorrect.

What you've been attempting to discover is which chain ring is more efficient. Your results don't surprise me (this from a guy who has ridden Rotor cranks for 9 years). I tried Rotor rings on my df for a year about 5 years ago. No observable benefit and more hassle, so went back to conventional chainrings.

The scientific data is limited on the benefits of Rotor rings. As far as I can establish, they have only been found to be more efficient in 30 second Wingate tests. So Ratz' comment that he notices a benefit when he is going full effort is no surprise. If beating people to the top of very short steep hills, or sprinting for the finish line, is your thing then Rotor rings are the way to go. Outside of that, I'll be guided by the results of your real-world testing.

Thanks...
 

LarryOz

Cruzeum Curator & Sigma Wrangler
Thanks Blair _ I appreciate your kind words and your encouragement.
per Ratz: If you think you are faster wearing purple and it doesn't in fact make you slower; then wear purple.
I think red socks make you fastest... :)
 

LarryOz

Cruzeum Curator & Sigma Wrangler
I knew it! Definitely wearing red socks for any record attempt!
 
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snilard

Guru of hot glue gun
Just because the result isn't what was expected, doesn't mean that it is incorrect.
I can agree with this sentence but not with whole paragraph. Result is incorrect because of incorrect measurement. I think that difference between Q and round may be smaller than measurement error in this case. I think that measurement of bio-mechanics is very tough and cannot be measured in such simple way. Measurement of weight of bike, of rolling resistance of tires and also of aerodynamic drag coefficient is "simple" measurement if some physical phenomenon, but measurement of human body efficiency is not easy.
Yes, Larry is doing great job to measure what is better.
 
Thanks Blair _ I appreciate your kind words and your encouragement.
per Ratz: If you think you are faster wearing purple and it doesn't in fact make you slower; then wear purple.
I think red socks make you fastest... :)
Missed opportunity here Larry. Ratz I think a pink bunny suit with fuzzy pink bike shoes will make you go faster. :)
 
Missed opportunity here Larry. Ratz I think a pink bunny suit with fuzzy pink bike shoes will make you go faster. :)
We're talking about Larry! He needs a Roadrunner costume to go faster! MEEP! MEEP! Look how aero that plume is!
42059quick-roadrunner-mascot-costume-000.ashx
 

Tuloose

Guru
Thanks for compiling that data Larry.
Your more science based measurements match my own "seat of my pants" opinion.
Six years ago I bought 2 sets of Q rings, one set for my P-38 and one for my wife's Giro, after reading the breathless accounts of their superior performance on the BROL forum.
I found there to be no discernible difference between the old round rings and the expensive Q rings. My wife can't tell any difference either.
A friend with a Bacchetta Corsa was going on a mountainous 10 day tour and traded crank sets with me to see if they would improve his climbing ability.
If he felt a difference he was going to purchase a set of Q rings but he had a similar experience to mine - no difference.

Yet Q ring users claim all sorts of benefits from a decrease in knee pain to increased performance.
Could it all be due to confirmation bias?
I can't speak for others. I can only say that for me they were not all they are cracked up to be.
 
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