K.O.P.S.

dennisn

Anyone out there up for a discussion / knock down drag out fight over whether the "knee over the pedal spindle" is of any value or not?

I'm sort of the opinion that todays(and yesterdays) frame geometry makes this a moot point. It would seem that that is pretty much where everyones knee's ends up anyway. Of course, there is always the question of what part of the knee lines up. Front, back, or somewhere in between. I've heard all three.

I would be interested in just exactly who was responsible for this idea. Is this even known? Or is all this just pass down info from an unknown source?

I have read Keith Bontrager's "The Myth of K.O.P.S." and found it most interesting if somewhat lacking in detail. The idea that your bodies center of gravity needs to be in a certain relationship with the bottom bracket sounds resonable, although it's highly unlikely that you will be able to find this point.

In any case just food for thought.

keef66

"I'm sort of the opinion that todays(and yesterdays) frame geometry makes this a mute point"

I hope you mean moot point. Or are we going to do this in the medium of mime?

There is no logical justification for having a particular piece of bone vertically above the pedal spindle, but for most people on most bikes, it's a handy starting point.

I doubt it would work for a recumbent.

Grill

KOPS = clownshoes

dennisn

keef66 wrote:

There is no logical justification for having a particular piece of bone vertically above the pedal spindle, but for most people on most bikes, it's a handy starting point.

I agree that I don't KNOW OF a logical reason, but it doesn't mean there isn't one. It's been part of cycling lore for many years and like you say it's a handy starting point. So, if it's not the answer to whatever problem it solves or was intended to solve, what is the answer. Or better yet what was / is the problem?
What do all the fit experts say?

sungod

kops is just a convenient convention, not wildy wrong, but not automatically right either

for me, the best set up isn't kops, but it's down to individual body geometry vs. bike geometry, not dogma

dennisn

sungod wrote:

kops is just a convenient convention, not wildy wrong, but not automatically right either

for me, the best set up isn't kops, but it's down to individual body geometry vs. bike geometry, not dogma

You're remarks sort of asks the question "If not KOPS, then what?"

Maybe since KOPS is an older(for lack of a better word) idea / theory the person coming up with it wasn't concerned
with comfort, only how fast can you pedal a bike and what's the best position to accomplish this. This assumes that it had it's origins in bike racing. KOPS would seem to put your weight over the pedals more than some other positions. Granted you are seated but still having a bit more leg weight helping push the pedals can't hurt. Or maybe whomever this was thought that this was the most efficient position to transfer the bodies power through itself and on to the pedals(hmmmm, sort of the same thing?). :?

sungod

the "what" is correct set up for *you*

only way to find it is a good bike fitter or experimentation

i'm pretty lanky, i find a position with knee a bit behind pedal axle is 'best', i.e. my power meter shows i sustain more power, and on long climbs i find it easier than kops

but i'm sure it varies depending on leg geometry, we're all different proportions

imho kops is just too convenient, it's a kop out for lazy bike fitters (soz)

dennisn

sungod wrote:

i'm pretty lanky, i find a position with knee a bit behind pedal axle is 'best', i.e. my power meter shows i sustain more power, and on long climbs i find it easier than kops

imho kops is just too convenient,

Damn, now at 65 I've got to buy a power meter? When does it end? I just put a carbon bar on my bike. Isn't that enough?

I kind of agree that KOPS is too convenient. Still, like you say, your knee is "a bit behind....". Plus there's always the chance that it IS that easy. :?

sungod

i spent a while experimenting, the bike fitter was really keen on kops, i wasn't, so eventually i went my own way

the pm really only verified how i felt, imho if it feels right, it probably is

dennisn

sungod wrote:

...... imho if it feels right, it probably is

Hmmmm, sounds like an old slogan I seem to remember. If it feels good, do it.

sungod

this is what i tell my gf

dennisn

sungod wrote:

..... the bike fitter was really keen on kops,

Meant to ask before. Did this bike fitter offer any insight as to the why's and wherefore's of KOPS?

sungod

tbh i didn't ask, i just thought sigh let's get on with why i came here, footbeds+spacers, and i can move on

ricky1980

riding position has two factors 1) efficiency 2) comfort...

KOPS probably gives best efficiency in most body geometry...someone correct me if this is not the case. as in terms of kinematics, it optimises the levers and actions of your legs.

but KOPS doesn't guarantee 100% comfort, so there is the fore and aft adjustment in the cockpit area. and also there is the riding style each person prefers or used to. there is not point in forcing someone in a position he/she doesn't feel comfortable and cannot get used to. so i guess that's where the compromise lies.

edit: expanding on my second paragraph, the issue of lining up the knee to the axle seems to make sense as it minimises out of plan action. The axle of the pedal is where your foot is exerting force onto, and knee joint is where the quads are exerting downward force through. so makes sense to have those two points lined up to optimise motion transfer. imagine the pedals are drawing a circle and the force applied is a tangent to the arc of the circle when pedal is horizontal. the maximum torque with least amount of force applied is if the force applied is truly vertical. obviously this is simplistic view of it, as body muscles and geo works a bit differently.

sungod

ricky1980 wrote:

<...>
KOPS probably gives best efficiency in most body geometry...someone correct me if this is not the case. as in terms of kinematics, it optimises the levers and actions of your legs.
<...>

afaik there's no scientific evidence that kops is optimum, it's one of those things that's widely quoted and sounds a bit plausible until you start digging

origin seems to be in people looking at riders, seeing their knees usually were sort of over the axle in a certain position and then choosing a convenient anatomical lumpy bit as the measurement point, add catchy acronym, kops is born

if it were to be best irrespective of femur:tibia:foot ratios and all the other individual variations it'd be amazing

i think kops gives a reasonable starting point from which to look for the best position (at least on a road bike), but you could use kops+5mm as the reference point, or kops-5mm, and they'd have just as much validity

some opinions on the subject...

http://hypercatcycling.wordpress.com/20 ... l-spindle/
http://www.stevehoggbikefitting.com/blo ... oad-bikes/

dennisn

sungod wrote:

ricky1980 wrote:

<...>
KOPS probably gives best efficiency in most body geometry...someone correct me if this is not the case. as in terms of kinematics, it optimises the levers and actions of your legs.
<...>

afaik there's no scientific evidence that kops is optimum, ......

Of course, by the same token, is there any scientific evidence something else is more optimum? Add to that the fact that there are most likely 50 definitions / opinions of optimum. Do we even know if whomever came up with this idea / theory that optimum anything was what he had in mind? Do we even know who named this thing KOPS?