Wiggo's Elliptical Chainring?

[tockit]

Anyone notice Bradely Wiggins running an elliptical chainring on his TT bike yesterday?

I thought those things were "old school" since that fad didn't seem to pan out 15 or so years ago, no?

Is there really an advantage to those, or are they still like a personal preference item?


That Cervelo P4 TT Bike that Sastre rode yesterday looked phenomenal. Too bad he didn't ride a phenomenal time on it.

I was really impressed with that bicycle though.

Here's a link for anyone interested:

http://www.cervelo.com/bikes.aspx?bike=P42009

 

[avanti]

Anyone notice Bradely Wiggins running an elliptical chainring on his TT bike yesterday?

I thought those things were "old school" since that fad didn't seem to pan out 15 or so years ago, no?

Is there really an advantage to those, or are they still like a personal preference item?
.......

I believe Christian Vande Velde also rides elliptical chain rings. Some track riders use these -- they work with fixed gears provided they are not too eliptical.

 

[Old Crank]

Elliptical Rings

I also thought they were a fad in the late 80s - early 90s.

I guess a few riders still believe.

If I'm not mistaken, Bobby Julich used to ride them too right up until he retired.

Wonder if Wiggo wears bell bottomed pants too?

 

[oldcrank]

I believe Christian Vande Velde also rides elliptical chain rings. Some track riders use these -- they work with fixed gears provided they are not too eliptical.

I've never seen elliptical rings on the track. Who did you see using them?

 

[El Imbatido]

Ha, you two guys who posted above me, have the same user name although one of you guys have a space in it.

 

[mickkk]

Shimano Biopace. I had them in the 80s. I found them OK. Big 54 chain ring, could hammer along all day. I reckon they made hills easier too. They were light aluminium and turned to sharks teeth after 12 months, was then hard to get rings that had the same pattern as the crank.

The science was proved in the lab, but hard to get accurate results on the road.

However, if they are worth a few inches over a race, they could just be the difference at the finish like all the other tweaks.

 

[lean mean &green]

elliptical chainrings are an attempt to minimize the deadspots in the pedaling cycle. Top dead center (TDC, 12 o'clock) and bottom dead center (BDC, 6 o'clock) are weaker from the perspective of mechanical advantage than other parts of the pedal stroke. the simplest way to say it is that they make pedaling easier at these weak points in the pedal stroke and slightly harder where your physiology produces an advantage in an effort to increase efficiency.

Despite your best efforts and what some people say you will NEVER remove these deadspots. You may be able to mimimize them with technique/neuromuscular coordination and this type of chainring to some degree.

i'm embarrassed to admit that these chainrings actually make a lot of sense from the standpoint of biomechanics because alot of purists will laugh at the idea.

there is no need to make them from a softer metal like aluminum. that will decrease rotating mass (a very good thing) but shorten the life-span of the product (a very bad thing for your wallet) depending upon your goals.


Too much information:
i've never used these chainrings but my hunch is that front derailer performance would be effected at least a little bit. i've never heard complaints to this effect so they are either non-existent or hardly perceptable.

 

[badboyberty]

Rotor Q-Rings, seem to have got it sussed a bit better than Shimano did.

http://www.rotorbikeusa.com/

 

[avanti]

I've never seen elliptical rings on the track. Who did you see using them?

I saw them at a world cup event at ADT Los Angeles a few years ago - I do not remember the rider or country. There was some related discussion on fixedgearfever.com

 

[tockit]

I had a set that came on my first road bike about 20 or so years ago.

I couldn't really tell any difference in my pedal stroke with the ellipticals versus a regular chainring.

 

[bbgobie]

Q-rings as mentioned

Sastre uses them, as well as a few others on Cervelo Test Team.