Bridgestone RS 800
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Ja - das ist tatsächlich sogar der Kern des Gedankens bei den Biopace-Kettenblättern: Die spezifische Form des Kettenblatts orientiert sich an der in den unterschiedlichen Kurbelstellungen jeweils verfügbaren Beinkraft des Radfahrers, um so die Leistungsabgabe zu optimieren.oder gibt es eine feste Position in der die Kurbel im Bezug zur Elipse angebracht sein sollten?
Daher spielt - wenn man das System überhaupt ernst nehmen möchte - die definierte Position der Kettenblätter zu den Kurbeln die entscheidende Rolle.
Sheldon Brown konnte etwas mit Biopace anfangen, daraus schließe ich, dass es zumindest kein völlig wirkungsloses System gewesen sein kann. Allerdings sah er Vorteile vor allem für Tourenfahrer, Zeitfahrer, Triathleten und Mountainbiker:
What Are They Good For?
Biopace chainwheels are particularly suitable for touring cyclists and time trialists, or any application that involves a steady, fairly constant cadence. They allow healthy, efficient pedaling at slower cadences than is possible with round chainwheels. They are especially suitable for triathletes and mountain bikers. The triathlete benefits because the motion is a little bit closer to that of running, making the transition easier.
The mountain biker particularly benefits, because the Biopace design somewhat smoothes out the delivery of power to the rear wheel. In climbing on loose surfaces, the limiting factor is often traction. The rear wheel tends to break loose during the maximum power phase of the pedal stroke, wasting most of the cyclist's energy. The Biopace chainwheel works like a storage device, storing power during the main power phase of the stroke as the feet accelerate, then delivering the stored power to the rear wheel during the "dead center" phase when the cranks are nearly vertical. The same average amount of power is delivered to the rear wheel, but in a smoother, less pulsating flow. The bicycle moves at a more even speed. All the energy is used to propel the bike forward, without the high-power peaks' spinning the rear tire or causing the bike to "wheelie."