Elliptical chain rings don't work ...

[castlerobber]

With that progression will the next bike have 140 mm cranks?

Oh, and I forgot the 155mm cranks and e-ring on the Q.
One never knows. Might take a few more years, though.

 

[bladderhead]

Progress... 5mm cranks. The ankleflappers can use clipless pedals and keep their legs straight and just move their feet up and down. Very aero.

 

[cranky cyclist]

Would testing Qrings and round rings on an indoor track with a power meter help to solve the problem? If q rings work you should see more power then with round rings.

 

[super slim]

Would testing Qrings and round rings on an indoor track with a power meter help to solve the problem? If q rings work you should see more power then with round rings.

Would a crank with a 38T Qring and a 50T round ring and a spider power meter and a hub power meter, so you could pedal at the same RPM, and road speed to check power efficiency work?

 

[Jim Parker]

For me, I like Q-rings because the perceived effort at the same power is less. And I do like to pedal with my ankles.

 

[ccf]

If someone can find the original work please share it.

Here it is: http://www.tradewindsports.net/wp-c...BLISHED-PhD-Oval-vs-round-sub-max-and-max.pdf

My interest in this subject is mainly the influence of noncircular rings on stress/strain/pain of my knees. I think Tables 3.3 and 3.2 indicate that the noncircular rings lower the stress on knees. I've reached out to Professor Leong for confirmation. I'll let you know what I learn.

-Cliff

 

[Bruce B]

Would a crank with a 38T Qring and a 50T round ring and a spider power meter and a hub power meter, so you could pedal at the same RPM, and road speed to check power efficiency work?

Or could one substitute the 38T Qring with a 50T Qring and shift the chain by hand rather than using a derailleur?

 

[ReklinedRider]

Here it is: http://www.tradewindsports.net/wp-c...BLISHED-PhD-Oval-vs-round-sub-max-and-max.pdf

My interest in this subject is mainly the influence of noncircular rings on stress/strain/pain of my knees. I think Tables 3.3 and 3.2 indicate that the noncircular rings lower the stress on knees. I've reached out to Professor Leong for confirmation. I'll let you know what I learn.

-Cliff

Knee stress relief is my main interest in oval rings too. Decreased lactate production, yada yada yada, would just be a nice bonus.
It will be interesting to hear what Dr. Leong has to say about those two tables. I think I see what you're seeing in them; if so, it looks like Osymetric rings may be even better than Rotor in that regard (?)

I wonder if any0ne has done similar testing on eccentric rings that reach the theoretical optimal eccentricity of 1.29. The Rotor Q rings he tested were at 1.13 while the Osymetrics were at 1.24. With their increased ovalization, I wonder if the Rotor QXL rings reach 1.29.

 

[RojoRacing]

Anyone ever love their oval rings for a time and then magically somehow fall out of love with them? So I love the q-rings on the V20 and I loved them on my Ridley DF bike and again on my latest DF bike the Domane but that was in Northern California. So get this I move to Socal 4 weeks ago and somehow every ride down here my oval rings have felt oval and oddly timed and no I've moved nothing. I tried riding it 4-5 times hoping I just ate some funny donuts but then I broke down and tried adjusting the position forward and back. Sadly I because I'm using a 110mm compact crank I can only use positions 3,4,5 but I feel like the sweet spot now would be position #1 of even one more step beyond but I can get that with this setup. So 3 felt fine in the past, 4 & 5 feel more oblong I tried going beyond position #1 just to check but it felt as bad as #5 but on the other side of the power stroke. Right now #3 feels like the best compromise but it is a compromise and I feel it's cutting down my power.

The oddness I feel is also reflected in my Vector Power meter data in that my two data fields that focus on my pedal smoothness and efficiency and considerably less than what I've seen on the V20. On the V20 I record over 90% in Torque Effectiveness and around 30% in Pedal Smoothness (30-35% is about max for anyone) on the DF bikes I'm only recording 70% and 20% which is a massive difference and this seems the same for even when I was liking the oval rings on the DF bikes. So is maybe the recumbent position confusing the Garmin and making it think I'm smoother than I really am because it sees me pushing through what would normally be the dead spot on the rotation? Do I simply pedal that much smoother in the stretched out position? Why did I suddenly start not liking my oval rings?

I don't have my V20 down here to ride and compare right now so who knows if I'd still like the oval rings on it after my move. I'm having my family ship me my original round rings to toss on the DF bike to see how they feel and what they do to my data.

So weird

 

[RAGBRAI VI]

The drivetrain on my 451 Quest is stock, 155 cranks and an elliptical chain ring. My knees have never been happier. It felt odd at first, due to the 155 cranks, but I quickly adapted and didn't notice the elliptical ring until I had ridden for a month and was cleaning the chain. Find what makes you comfortable and ride it!

 

[jond]

Clearly the move to socal has upset your equilibrium rojo. Change is inevitable .

Or your bent legs have grown to make you the recumbent dork you were meant to be.

One day my first wife woke up and decided to up and kick me out.

Putting your round rings back on the df will be a helluva of a lot cheaper.

 

[LarryOz]

I really just like the way the chain ring bounces up and down as I pedal. I gets me hypnotized and I am sure it makes me faster just watching it go up and down!

 

[paco1961]

When I built up my S40 - first recumbent - I threw on the Ultegra 172.5s I had on my gravel DF. Knees were immediately unhappy. Switched to 155s and have not had a knee twinge since. No oval rings. Just boring old circles.