Well to put it simply (and a bit dramatically) Rotor Cranks are what may be
the biggest performance enhancing add-on available on the market today.
To give a better description... While conventional paired
bicycle cranksets have been around since the dawn of the
bicycle and they work pretty well, however
they do have one fundamental weakness. During the rotation cycle of a conventional
crankset there is a point when the rider is not producing any power. On an
upright(standard Bicycle) this is when the cranks are straight up and down.
This point varies widely on recumbents. Rotor cranks are the latest in a long
line of products designed to eliminate that "dead spot". Rotors use
a system of cams to make sure that your cranks never become aligned in a way
that doesn't allow you to produce any power. Your feet will be at the one o'clock
and six o'clock position when they would be at twelve and six on conventional
cranks.
Other attempts have been less than successful. Remember elliptical Biopace
chainrings? Okay now resume trying to forget them. As bad as Biopace was it
was probably the closest that anyone had ever come to finding the magic bullet
until Rotor came along. Bad experiences with other gizmos and widgets that
claimed to eliminate the dreaded dead spot didn't have me in a very optimistic
frame of mind when Rotor cranks first appeared on the scene last year.
Then a couple of interesting things happened... First of all a very prestigious
pro road team Spanish outfit( ONCE) tested them and reported very favorable
results. I also read a few scientific studies that at least sounded good.
I also learned that there is some real science behind the Rotor system. It
was created by a group of Spanish Engineers from the Aeronautical Engineering
School in Madrid in 1995. The cranks first became available in 1998 but a special
frame was required. In 2001 the current form (that uses a conventional bottom
bracket shell) came into existence. Then came the tests and the articles and
the ensuing press that finally got Rotor some attention on this side of the
pond.
Fitting took me about
an hour after I had read the instructions twice, to get my
head around the offset system. When you fit the cranks you
have a choice of amount of assistance the sytem will give
you, this is simply the position of the offset and will offer
the crank at between 7and 12 degrees depending on riding
style and type of use. Once set by loctiting the BB into
the shell and waiting a few hours the riding can commence.
