Did anybody else catch the video of the elliptical chain ring that Julich was using on his P3C? The commentators said that he used them in every time trial. What gives?
BTW, I’m posting this in my just arrived Peaceful Tribe T-shirt and hat. Very nice…
Spot
Hi Spot,
He has used that chainring for several years, it is called an Osymetric. French made, hard to find.
The premise is, a rider pushes a higher gear on the downstroke and a lower gear when in the 12/6 dead spot position, allowing the rider to spend more time in the power phase and less time in the dead spot area/void.
For 2006 Rotor is developing what we think is an improved version of the Osymetric, called the Q-Ring, which has several bolt holes and is completely adjustable for each rider’s unique power stroke. The chainrings will fit any 130/135mm BCD crankset, e.g. Dura-Ace, FSA and Campy.
Initial testing using SRM power meters shows lower heart rates at the same power production (which is great for endurance athletes). I have been on a couple prototype systems for about a month and love them, the production Q-Rings are coming in a few weeks and we will be taking our time testing the production units, and hope to have more information about a release date prior to Jan 2006.
The Q-Rings are not as effective as Rotor Cranks, as they do not remove the dead spot, however they do allow riders some of the Rotor benefits at a lower cost and less weight, and they can use their current cranksets.
And yes, they are being used in the Tour de France right now, David Canada (Prodir-Saunier Duval) is running them.
http://www.cyclingnews.com/photos/2005/tour05/?id=tour051/JD05tdfstg1004
Gary Tingley - RotorCranks.com
Besides time trialing are these kind of rings good for other disciplines such as climbing or sprinting?
Non-round chainrings have been tried and abandoned a few times in cycling history. The rings he rides effectively increase the gear during the time the cranks and horizontal, and decrease the gear when the cranks are vertical. In the mid-late 1980’s, Shimano’s “Biopace” chainrings (and knockoffs by other companies) tried non-round chainrings with the effective gear decreasing when the cranks where horizontal, and increasing when the cranks were vertical.
As I recall, the problem with chainrings like Julich’s is increased wear and tear on the knees. The problem with Shimano’s “Biopace” chainrings was a bouncy feeling to the pedal stroke.
See http://www.sheldonbrown.com/biopace.html for more details.
I still have a pair of 130mm BCD Biopace chainrings from my 1986 Cannondale, should anyone wish to purchase them :-).
Besides time trialing are these kind of rings good for other disciplines such as climbing or sprinting?
Julich uses O. Symetric on all his bikes.
Here are some pictures of Julch’s Soloist road bike used to win the Paris-Nice GC:
http://www.cyclingnews.com/tech/2005/probikes/?id=julich_csc_cervelo
"Besides time trialing are these kind of rings good for other disciplines such as climbing or sprinting? "
Yes, great for climbing, I am still testing them for sprinting, and have not had a chance to ride the new models, which are not like Osymetric or Biopace, these chainrings have only a small ovalization as in the photo (they almost look round) and only increase the effective gearing by one or two teeth. They do not hurt riders knees.
Gary - RotorCranks.com
Gary,
Any insight into the front wheel of the rider in your photo? is that two seperate “mini-discs” at the hub? One big thick tube? what is going on there?
Kevin
I’m tempted to try them. Those Osymetric chainrings Bobby Jullich was using on his P3C for yesterday’s TdL TT were quite obviously oval looking. Maybe the trick to safe riding is to get ones like yours which are less pronounced in their ovalness. Maybe less radical but still giving some advantage?
"Besides time trialing are these kind of rings good for other disciplines such as climbing or sprinting? "
Yes, great for climbing, I am still testing them for sprinting, and have not had a chance to ride the new models, which are not like Osymetric or Biopace, these chainrings have only a small ovalization as in the photo (they almost look round) and only increase the effective gearing by one or two teeth. They do not hurt riders knees.
Gary - RotorCranks.com
I guess they are not good enough to win the TdF KoM sprint, we saw that today when David Canada lost to Thomas Voeckler in the sprint.
Did it look like Bodrogi was using some kind of aymmetric chainring today? It wasn’t very pronounced but it did look out of round a bit.
Gary,
Any insight into the front wheel of the rider in your photo? is that two seperate “mini-discs” at the hub? One big thick tube? what is going on there?
Kevin
Hi Kevin, I have no information on that wheel, first I have seen it.
Gary - RotorCranks.com
The wheel is a Campy wheel, re-badged as a Fulcrum (which is a subsidiary of Campy,) with two seperate carbon fiber discs epoxied on to the wheel over the hubs/spokes.
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More Canada on Rotor Q-Rings, Saturday’s TT:
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It looks like Vino is using the Osymmetic too:
http://grahamwatson.com/gw/imagedocs.nsf/updateframesetcall?openform&05tdfSt20
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Got another question to pose here…
How well does the front deraileur handle the increase and decrease in effective teeth on the chainring? Are there issues with it falling off (chain)? BTW- my coach i believe is trying to become a US distributor for the Osymetric ring.
When will q-rings be ready for purchase?
"When will q-rings be ready for purchase? "
No idea if they will even make it to production, we are conducting tests, and have riders in the field testing the prototypes. Based on the findings, the factory will make a decision to manufacture them for the public. No date has been set.
Somewhere recently someone quoted the CSC team mechs saying that Julich’s bike was a bear to adjust on the front end. No issues once it was adjusted…but it seemed like he was saying the margin for error is extremely reduced…at least that’s my third hand interpretation…
"When will q-rings be ready for purchase? "
The bigger question is how much are they going to cost. The can’t cost much more than a normal ring to manufacture but let’s just wait and see what the retail is once they first come out.
After the novelty wears off and or when they start showing up used on ebay, prices will stabalize.