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Saddle fore aft ? help !

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Saddle fore aft ? help !

Old 03-28-22, 02:12 PM
  #51  
zandoval 
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Adjusting that saddle is real important. There is not a real formula. I have noticed that moving the saddle forward or back just a few millimeters has made tremendous changes in my ride now that I am a geezer. Same for degree of angle on the nose of the saddle. Same goes for the bike set up. I have two bikes set up exactly the same using measurements between seat, crank, and bars, and the saddle position is different even thought they use the same saddle. Of course one is more of a gravel bike then the other so there is a big difference per say.

My suggestion is don't think too much about it and just continually adjust your saddle till ya find your sweet spot... then ride, ride, ride... Happy Happy, Joy Joy...
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Old 03-29-22, 04:28 AM
  #52  
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Someone mentioned he doesn’t like to use the balance method because he doesn’t ride no-handed. I sometimes like no-handed but I don’t need a specific saddle position to be able to do that. For me the balance position is not for no-handed riding.

What a good balance setup really allows me to do is shield my body from feeling hard shocks. If on the saddle I have good fore/aft balance, I can easily lift my hands off the bars just a centimeter or so and let the front wheel judder around if I’m on some dodgy roadway. I also can lift my butt off the saddle the same little bit and get some bounce clearance under that as well.
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Old 03-29-22, 05:17 AM
  #53  
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Originally Posted by Carbonfiberboy View Post
The bolded part is fun because that's the thing that the balance method relies on. The idea of starting with KOPS has nothing to do with pedaling mechanics, only with balance. It's just an easy way to get the rider close to being in balance, no more, no less. There's really nothing to argue about. Simple inspection should be enough to convince anyone that there's no scientific method for determining this balance point. It depends on the rider's proportions, weight distribution, pedaling style, and surely other variables which are also impossible to measure by any means other than riding one's bike.
The point is not that both balance and KOPS are related to gravity, though balance is intimately dependent on gravity and KOPS is not. KOPS points out the geometry and physics that the leg creates its maximum torque (driving) with the crank when the foot is farthest from the BB axis, and this happens when the crank arm and the knee to pedal path are perpendicular. At that point the maximum fraction of the force from the leg is converted into torque. Some is still lost to angular crank and BB flexing, but the jury may be out on whether that energy storage is loss or still available for propulsion, but thatís another topic. The fallacy of KOPS is that this happens once per revolution regardless of whether the bike is vertical or recumbent. So what I see from KOPS is that at all bicycle angles from upright to Ďbent there is a point of perpendicular drive, and that it can be close to a balance position in an upright bike. My balance position is usually with my knee a few cm behind KOPS, so it is not perfectly satisfied by KOPS. But my balance position is important not because of drive efficiency but to enable a position which supports my body in several positions which I like: riding on hoods, drops, and hooks, and with my hands or butt only lightly connected to the bicycle. This happens when my body CG is somewhere behind the BB plumb line. If I ever lose weight again, my riding position will probably move forward by a few cm.

An additional complication is the angle between the femur and the knee-to-pedal path near the maximum torque point (I say it this way because we donít know what point on the knee is the actual pivot, and how to consider the offset of the foot). The optimum femur angle at the point of maximum chainset torque is a good question, and I think itís significant for knee health.
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Old 03-29-22, 05:27 AM
  #54  
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Fore/aft position depends on age, weight, condition of the rider, the bike, and the type of event.

TT bikes have the rider's CoG quite forward for aerodynamic purposes but the rider typically loses aerobic power.

If a normal road bike position has the rider having difficulty holding a stable, comfortable position, it is a good bet that their breathing capacity is reduced by excessive recruitment of muscle to stabilize the torso.

Bring a 5mm and mess around on a training ride until you are comfortable. I cannot hold the positions of my youth and do not even try.
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Old 03-29-22, 09:21 AM
  #55  
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Originally Posted by PeteHski View Post
No, one of these:-



Makes bike setup experiments very simple. I can change saddle setback on the fly in a couple of seconds.
WOW! Great! and really super light!, must be a joy to ride!
LOL!
Ride On
Yuri
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Old 03-29-22, 10:01 AM
  #56  
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...so, KOPS, was (and can still be) used for a 'ROAD bike' start point. Back when there was little/no science related to 'position'.
It is directly, immutably tied to saddle height ON A ROAD BIKE with geometry close to traditional road and rider use.
Rider/Coach would set up saddle height, flatten/level the saddle and then set the setback; discuss and deal with reach/stem length. Then 'tune' from there, over a period of minutes thru weeks; maybe even longer.
Ischial Tuberosity became part of all this because, the 'knee' is quite wide/long. It's just a 'std spot', not any scientific thing. A standard spot. Without that (as OP noted) it could be most anywhere on the knee.
A 'start point' for what has, and still mostly is, a common 'road' position.
I would NOT suggest that it works for any other setup (it might - don;t know... don't care)
The OP never noted WHAT they were trying to use KOPS for... and is gleefully enjoying the result of their OP.
I would not think it's used for current mtb, and certainly not DH or Enduro, maybe XC? Certainly not for TT or TRI with a TT setup.
... do we think KOPS or balance works for a cruiser ? maybe a 'Bent' ? CX or gravel? aaahhhh, something we can argue about! LOL!
the whole for/against KOPS/BALANCE is sadly, very lilliPUTIN/Big-Endian...
start somewhere, ride, figure it out.
Ride On
Yuri
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