What’s the fuss about
KOPS? Knee over pedal spindle has had a lot of bad press over the last few years, but is there still value in the old dog yet? Lee Prescott, fitter and frame builder, thinks so.
K
OPS, or Knee Over Pedal Spindle, as I’m
described in his Medical Guide for Cyclists, and
sure you are well aware, refers to the
Phil Burt advocates its use – but only when
practice of using the relationship between
taken dynamically – in his book, Bike Fit. But
the knee (which part is also up for debate,
recently, KOPS has become something of a
depending on who you refer to) and the pedal
pariah within the industry, with some fitters
axle, in order to determine saddle set back. Or so
suggesting that anyone using the method should
the myth goes.
be avoided.
But where did this come from? It’s pretty hard
Keith Bontrager was one of the first high-
to define a clear source, but Fit Kit Systems from
profile designers to cast aspersions on the use
the 80-90s used it as part of its protocol, and
of static KOPS. His famous white paper
there is mention of it in the CONI Cycling manual
discusses how the use of a static plumb bob
from 1972. It’s likely that it proliferated due to it
measurement is too heavily influenced by gravity
being a simple measurement that anyone could
and becomes irrelevant as soon as the bike is on
take, with an inexpensive plumb bob, to get a
an incline. Part of his reasoning is that it has no
cyclist pretty close to a decent saddle set back. I
biomechanical basis. Now it’s important here to
know that when I first started building frames in
remember that this was written before the advent
1986 it was a pretty standard way of deciding on
of power meters or dynamic motion
seat angle.
capture. Steve Hogg also wrote about how he
But this is all back when bike fitting was all
was unconvinced by the KOPS method in his
just a practice of static measurements and
blog piece on Seat Set-back from 2011, pointing
conversion formula. The KOPS method became so
out that its more important to create a saddle set
endemic within the industry it became the de facto
back that will unweight the torso. Both of these
process. Dr Andy Pruitt uses it in his protocol