Updated March 15, 2000: A New
Campagnolo Patent for an Updated Electronic Shifting System
Click here for more information!
You've probably never heard about it, but in 1996
Campagnolo quietly patented a design for an electric,
electronically actuated rear derailleur. In fact, prototypes
existed as early as 1994, and Campy secretly patented some
aspects of the electronic system in Italy prior to obtaining the
You'll find the full details at this
location on the U.S. Patent Office's server, but we've
excerpted a diagram and a brief summary here.
Could this be the system that replaces Mavic's
now-defunct "Zap"? Only time will tell. But it's clear
that Campy is working on the next generation of shifting.
A few notes:
The derailleur looks much more like a
"normal" derailleur than Mavic's version. An
actuator motor (see the picture below) is located inside
the derailleur body, pushing and pulling (as the cable
does in the current mechanical models) to move the chain
from cog to cog.
Like Mavic, it uses a battery stored
inside the handlebars. But it builds on Mavic's system by
using a tiny generator in the lower jockey pulley to
recharge the onboard batteries. Unlike the Mavic system,
the shifting does not rely on the movement of the jockey
pulleys; the motor does the work.
A disk/sensor combination inside the
motor that moves the derailleur "senses" which
gear the bike is in and relays that information back to
the microprocessor that makes the whole thing work.
Shifting is shown either on Ergo-like
levers or on a separate keypad.
It was invented by Valentino Campagnolo
From the U.S. Patent web site:
INVENTORS: Campagnolo; Valentino, Vicenza, Italy
ASSIGNEES: Campagnolo S.r.l., Vicenza, Italy
ISSUED: Jan. 2 , 1996
FILED: Dec. 27, 1994
SERIAL NUMBER: 364459
INTL. CLASS (Ed. 6): F16H 9/24; F16H 59/00;
U.S. CLASS: 474-070; 474-080; 474-103; 474-110; 474-116;
FIELD OF SEARCH: 474-70,80,82,103,110,116 ; 280-238 ;
AGENTS:Sughrue, Mion, Zinn, Macpeak & Seas;
ABSTRACT: A powered control device for speed change in a
bicycle comprises an electric motor directly mounted onto the
rear derailleur and is provided with an encoder for detecting
the position of the rear derailleur.
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