asymmetric chainrings

recedite

Anyone using these? I used to have one on a MTB years ago, the smallest ring. It seemed good for going up steep hills, but was too "jerky" on the flat.

Eamonnator

recedite wrote: »

Anyone using these? I used to have one on a MTB years ago, the smallest ring. It seemed good for going up steep hills, but was too "jerky" on the flat.

These were called "Biopace" rings, they were all the fashion for a while.
Bradley Wiggins used something similar in the time trial in the TdF a couple of
days ago. He seemed to get on all right with it. http://b-static.net/vbulletin/images/smilies/wink.gif

ednwireland

http://www.rotoruk.co.uk/qrings.html

there you go

hated em on mtb's always felt weird to me (even weirder was the road biopace and those had less assymetry) cant imagine riding those things wiggo has on the TT bike

CramCycle

I used biopace on my fixed gear for ages and had no problems with it, I'll even go as far as to say it improved my top speed noticeably.

The O-symmetric and the biopace are different though aren't they?

Correct me if I am wrong but the Biopace suits climbing and the O-symettric suits flat terrain according to the theories behind both?

Lumen

The Wattage group has some amusing discussions of asymmetric rings which seem to boil down to whether you can "game" a power meter.

As far as I know no-one has produced any research which shows them to be quantifiably better or worse. There are similarities to the crank length debate, in that it takes so long to get used to the change that the riders fitness can't be taken to be a constant.

Eamonnator

David Millar had an asymmetric chainring on his bike in TdF today, as did Bradley Wiggins. Surely, there has to be an issue, changing from inner to outer chainring, Do they use a standard front mech?

Lumen

Eamonnator wrote: »

David Millar had an asymmetric chainring on his bike in TdF today, as did Bradley Wiggins. Surely, there has to be an issue, changing from inner to outer chainring, Do they use a standard front mech?

I think they use a standard front mech, although Sky use Di2.

Electronic shifting theoretically allows the derailleur to move at a given point in the crank rotation. EPS definitely does this. I wonder whether this helps to combat the notoriously crap shifting of asymmetric rings.

niceonetom

Wiggins appeared to be back using mechanical Dura Ace on his TT bike the other day. He's dropped the chain during a TT more than once in the past so he obviously wanted to minimise the risk of bike toss.



Blurry but mechanical.

recedite

Eamonnator wrote: »

David Millar had an asymmetric chainring on his bike in TdF today, as did Bradley Wiggins.

On the day they were reeling in the breakaways going up cols de Madelaine and Croix de Fer, the ITV commentator said that "most of the Sky team" were using them, so its not just Wiggins, and its not just the TT bikes. I'm guessing that by this time next year there will be quite a few wannabees using them.