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View Full Version : Froome's chainrings from the TdF


Keith A
07-16-2017, 05:42 PM
Just saw this picture of Froome's chainrings -- they look pretty extreme. Has anyone tried something like this?

http://www.bicycling.com/sites/bicycling.com/files/styles/listicle_slide_custom_user_desktop_1x/public/Froome_DogmaF10_TdF17-4.jpg

Bruce K
07-16-2017, 05:47 PM
I forget what brand they are but he and Sky have been using them for years

The benefits are still being debated by a lot of folks but I would think they have done data that it is, at least not a detriment.

BK

Black Dog
07-16-2017, 05:51 PM
They are designed to make Froome a graceful bike rider. Mission accomplished ;)

bikinchris
07-16-2017, 06:23 PM
Various non round "Bio" and other named rings have been tried since the 70's at least. They all failed. Many people thought they made the pedaling feel wrong. The idea was reducing the stress on the dead points of the pedaling motion. Yeah.

Most riders spend a crazy amount of time trying to learn to pedal as round as possible. Riding with Souplesse is the goal. "Supple" round perfect pedaling is actually unobtainable, but the better you are at it, the more energy you save. People who use out of round chainrings have no hope of being smooth.

sales guy
07-16-2017, 06:30 PM
I forget what brand they are but he and Sky have been using them for years

BK


He uses the Ossymetric brand ones. Rotor has some oval rings as well in the Tour.

dgauthier
07-16-2017, 06:31 PM
(...) They all failed. (...)

Yes, didn't Shimano have a variation of this called "Biopace"? Froome's chainrings are yet another variation on the oval-shaped theme in that these look like they have sllightly flatter spots at intervals around the circumference (unless the picture is somehow distorted).

I am frankly surprised to see these in this day and age. I wonder if the team has any data indicating a benefit. Or perhaps, the placebo effect itself produces a benefit...

Matthew
07-16-2017, 06:33 PM
Every four revolutions they automatically pull his head down toward his stem.

ofcounsel
07-16-2017, 06:37 PM
I'm using Absolute Black oval chainrings on my mountain bike. They feel a bit odd pedaling at first on flat ground, but they feel like I have a little bit more traction and pedal natural while climbing.

yashcha
07-16-2017, 07:44 PM
I just started back on the rotor q chainrings. The last time I used them was back in 2011-2013, but I gave up on them because I hated how bad the shifting was, compared to the stock rings. A month ago I picked up a set here, 52-36, at a great price. The new generation of Q-rings seem to shift much better than the 2011-2012 version. Although shifting is noticeably worse than the stock 6800 rings, I find that it is still acceptable.

I use the epic KOM on Zwift as my fitness test route. On the stock rings, I typically average about 190 watts at 180 BPM (measured on a Stages) for about 27 minutes. At 62 Kg, this is my weekly sub FTP sweetspot workout. On the Q rings, I average the same watts, but my HR is around 170. This week, I will test how many watts I can push at 180 BPM.

For my riding style, Rotor seems to give a slight advantage, for that range of effort, which I have tested. Yes, very rudimentary testing and results so far, I hope to post more observations as I get more data points at different effort levels.

jumphigher
07-16-2017, 08:10 PM
I'd try them, I think there is something to their claims. I've used Biopace rings many times and have always thought they worked well. And I cant believe Froome would ride something that he thought was BS..

GonaSovereign
07-16-2017, 08:23 PM
Those are Osymetric rings, from France. Shimano would much rather Froome was on Shimano rings, so the Osymatrics must work for him.

torquer
07-17-2017, 02:22 PM
I'd try them, I think there is something to their claims. I've used Biopace rings many times and have always thought they worked well. And I cant believe Froome would ride something that he thought was BS..
The long axes of the ovals for Biopace and contemporary non-round chainrings are oriented 90 degrees apart.
https://en.wikipedia.org/wiki/Biopace
According to that company's Wiki page, Osymetric rings are "tailored to the pedal stroke of the individual cyclist." If they truly are customized, that could account for overcoming some inherent weakness in the rider's physiology.
It would be interesting to see what testing is performed by way of "fitting" their rings to a particular customer.
Or, it could just be marketing hot air...

Ti Designs
07-17-2017, 03:28 PM
Most riders spend a crazy amount of time trying to learn to pedal as round as possible.


Kinda like teaching a pig to sing...

Look a the human body on the bike, one muscle moves one joint in one direction, that can be applied to the pedal at a specific range. Example: The glutes extend the leg from the hip, so they can drive the pedal from 1:00 to 4:00 (the hip is behind the bottom bracket). The amount of force you can generate at the pedal depends on the size of the muscle and the mechanical advantage of the attachment points. The bio-mechanical efficiency of any muscle is related to where it is within it's range of motion.

Given that, you have the largest muscle group in your body, the glutes, pushing down. You then switch to the hamstrings - the longest muscle group in the body, pulling back. The amount of force you can generate is low, but the chance of cramping or injury is high. Then it's the hip flexors pulling up, to their end range of motion where efficiency is near zero. Then it's time to push forward with the quads...

You have two large muscle groups which push forward and down, and almost no ability to complete the pedal stroke on that side. The only way to pedal "round" is by limiting the use of the large muscle groups (which is really stupid) Forget about pedaling "round", learn how to use large muscle groups where they're effective. That's the whole game.

ultraman6970
07-17-2017, 04:05 PM
I used the shimano bio pace for racing and they sucked, the problem with those in specific is that you cant spin at all, once you are to a pace will keep it but if you need to accelerate you wont be able to do it comfortably as with rounded chainrings, after like a week I took them off.

Probably in a TT with a 54 chainring would had been nice but regular racing they sucked, everybody I know that used them had the same problem, for a lady that goes to the store the biopace was great, slow and steady pace.

I believe the rotor chainrings differ from biopace because you can swap the position of the curve to fits you better. I heard the reason Froomey fits weird over the bike is to accomodate those chainrings.

gianni
07-17-2017, 06:10 PM
Every four revolutions they automatically pull his head down toward his stem.

+1

It was driving me crazy the other day, like every 4 seconds. I'm amazed he doesn't overlap wheels more often.

Bring on the hate but it's hard to watch.

simplemind
07-17-2017, 06:18 PM
+1

It was driving me crazy the other day, like every 4 seconds. I'm amazed he doesn't overlap wheels more often.

Bring on the hate but it's hard to watch.

Yeah, *** is he looking at his power meter, or is he watching Game of Thrones (you don't have to watch every second)?

jlwdm
07-17-2017, 07:23 PM
Yeah, *** is he looking at his power meter, or is he watching Game of Thrones (you don't have to watch every second)?

Neither. If you had discomfort looking ahead all of the time like Froome does you would probably do the same.

Jeff

rustychisel
07-17-2017, 08:14 PM
Neither. If you had discomfort looking ahead all of the time like Froome does you would probably do the same.

Jeff

Discomfort like watching Team Sky arse in front of you for 3400km...

gasman
07-17-2017, 08:22 PM
Neither. If you had discomfort looking ahead all of the time like Froome does you would probably do the same.

Jeff

Is it pain or something else ? A buddy I ride with who's a Neurologist thinks it's a neurologic disorder like a tic. Maybe a combination of both.
Either way I'm going to challenge him to a bike race.:bike:

joosttx
07-17-2017, 08:42 PM
So, do these oval shape rings help to maximize the use of your big muscles?

Kinda like teaching a pig to sing...

Look a the human body on the bike, one muscle moves one joint in one direction, that can be applied to the pedal at a specific range. Example: The glutes extend the leg from the hip, so they can drive the pedal from 1:00 to 4:00 (the hip is behind the bottom bracket). The amount of force you can generate at the pedal depends on the size of the muscle and the mechanical advantage of the attachment points. The bio-mechanical efficiency of any muscle is related to where it is within it's range of motion.

Given that, you have the largest muscle group in your body, the glutes, pushing down. You then switch to the hamstrings - the longest muscle group in the body, pulling back. The amount of force you can generate is low, but the chance of cramping or injury is high. Then it's the hip flexors pulling up, to their end range of motion where efficiency is near zero. Then it's time to push forward with the quads...

You have two large muscle groups which push forward and down, and almost no ability to complete the pedal stroke on that side. The only way to pedal "round" is by limiting the use of the large muscle groups (which is really stupid) Forget about pedaling "round", learn how to use large muscle groups where they're effective. That's the whole game.

regularguy412
07-17-2017, 08:45 PM
So, do these oval shape rings help to maximize the use of your big muscles?

I dunno bout that, but probably just a good excuse not to have to shift gears!

Mike in AR:beer:

jlwdm
07-17-2017, 10:22 PM
Is it pain or something else ? A buddy I ride with who's a Neurologist thinks it's a neurologic disorder like a tic. Maybe a combination of both.
Either way I'm going to challenge him to a bike race.:bike:

In one article he said his neck gets sore and that he breathes better looking down on hard efforts.

Jeff

justaute
07-17-2017, 10:46 PM
Exactly. Not sure why many people continue to treat the contemporary oval chainrings as though they are the same as "biopace". Now, I don't know the efficacy level of these new designs, but they are certainly different from biopace. I want to try them, but can't quite find the the size I want. Just trying to an open mind.

The long axes of the ovals for Biopace and contemporary non-round chainrings are oriented 90 degrees apart.
https://en.wikipedia.org/wiki/Biopace
According to that company's Wiki page, Osymetric rings are "tailored to the pedal stroke of the individual cyclist." If they truly are customized, that could account for overcoming some inherent weakness in the rider's physiology.
It would be interesting to see what testing is performed by way of "fitting" their rings to a particular customer.
Or, it could just be marketing hot air...

cnighbor1
07-17-2017, 11:11 PM
Various non round "Bio" and other named rings have been tried since the 70's at least. They all failed. Many people thought they made the pedaling feel wrong. The idea was reducing the stress on the dead points of the pedaling motion. Yeah.

Most riders spend a crazy amount of time trying to learn to pedal as round as possible. Riding with Souplesse is the goal. "Supple" round perfect pedaling is actually unobtainable, but the better you are at it, the more energy you save. People who use out of round chainrings have no hope of being smooth.

they haven't failed I use them because they work for me

FreeFour
07-18-2017, 06:21 AM
This was my experience as well with an Absolute Black oval ring on the road.

I no longer use it, but felt more efficient at just-below-threshold efforts. Was not as big of a fan of them for sprinting, but there are certainly are those who use them effectively for that purpose too.

The debate that oval rings manage to stir up is always a joy to read. Anecdata all around :D

I just started back on the rotor q chainrings. The last time I used them was back in 2011-2013, but I gave up on them because I hated how bad the shifting was, compared to the stock rings. A month ago I picked up a set here, 52-36, at a great price. The new generation of Q-rings seem to shift much better than the 2011-2012 version. Although shifting is noticeably worse than the stock 6800 rings, I find that it is still acceptable.

I use the epic KOM on Zwift as my fitness test route. On the stock rings, I typically average about 190 watts at 180 BPM (measured on a Stages) for about 27 minutes. At 62 Kg, this is my weekly sub FTP sweetspot workout. On the Q rings, I average the same watts, but my HR is around 170. This week, I will test how many watts I can push at 180 BPM.

For my riding style, Rotor seems to give a slight advantage, for that range of effort, which I have tested. Yes, very rudimentary testing and results so far, I hope to post more observations as I get more data points at different effort levels.

chiasticon
07-18-2017, 07:09 AM
fwiw, Wiggins used them in his tour victory too. so Sky must see something in them. I think Wiggins actually switched off of them a year later when he raced the Giro (or something) and after not doing well, the maker of the osymetric rings claimed he would've won if he'd stayed on the rings. :rolleyes:

I have a club mate that switched to them this year. then he put a cassette with a 32 on it on his bike so he wouldn't have to change front rings, that's how bad the front shifting is. and he's on di2.

http://i.hurimg.com/i/hurriyet/75/0x0/55eb5e6bf018fbb8f8bca15d

Billybob62
07-18-2017, 08:29 AM
Every four revolutions they automatically pull his head down toward his stem.

hysterical.....and the poor mechanics must hate them.

oldpotatoe
07-18-2017, 08:34 AM
hysterical.....and the poor mechanics must hate them.

Yup, I've installed a few and the front der doesn't like them at all. Shift with zero pedal pressure and the chain won't get spit but smash the chain around in anger and it'll throw the chain every time.