Professional Cycling For the Fans - jullich's tt crankset

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View Full Version : jullich's tt crankset


pearcem
07-29-04, 02:31 PM
anybody see the little oln thing about the non-semetrical curve on bobby jullich's chainring on the final TT? it suposedly added 1 km on the flats and 1.5 climbing. Can anyone explain how this works, and if so, where can i get one :) thanks


ChiefCatchacold
07-29-04, 02:47 PM
He used them in last year's world championships (http://www.cyclingnews.com/worldsphotos03.php?id=photos/2003/worlds03/emtt/JDjulich_usa2) too, funny lookin things

rygreen
07-29-04, 03:02 PM
It's supposed eliminate the dead spot in your pedal stroke (where your foot comes over the top.) Same idea as Rotorcranks.


collegeskier
07-29-04, 03:02 PM
I believe the concept is that you have a more power region of you pedaling and a less powerful region. On a traditional crank this less powerful region is actually limiting from going faster and causing you to chnage your power output, making you more tired. With the funky crank set it is easier to pedal in this less powerful section thereby making your legs put out the same energy throughtout so you can go faster and not get tired I would think. At least that is what i picked up from OLN. Sort of like constantly shift for different regions of your revolution.

Timo
07-29-04, 04:59 PM
Reminds me of the old (late 1980's) Shimano "Biopace" blades. I still have them somewere in the old parts box. Came with the RX 100 gruppo on one of my first racing bikes.

holicow
07-29-04, 06:30 PM
The creator said they "weren't elliptical" comparing them to the Biopace rings. They looked like a similar shape, so I guess they are more asymmetric, or something. Similar concept, tho....

capsicum
07-30-04, 08:27 AM
biopace are not eliptical either. I don't know why everyone thinks they are just another eliptical ring.