ctak

According to bike fit gurus not limited to Bontrager and Hogg, handlebar position should be determined after one's ideal saddle setback and height have been established... and that proper weight distribution is critical to efficient oxygen intake and injury avoidance (of the 20 torso muscles used in breathing, 18 have postural implications… and will carry unnecessary tension when improperly enlisted/loaded).

Along these lines, I'm looking for articles by other well-regarded specialists that describe methods for arriving at proper weight distribution. I'll use this info to improve my own bike fit, particularly for 4+ hour rides where imbalances in posture and weight distribution can become intolerable


(1) Keith Bontrager's KOPs-debunking article on establishing a rider's seated center of gravity (1998)

"It should be easy now to see that a rotation of the leg/crank lever system about the bottom bracket is the same as a change in seat tube angle. A shallow seat angle has the same effect as rotating the rider in our diagram clockwise about the bottom bracket; a steep one does the opposite. In both cases, the plumb bob will swing away from the pedal spindle, but the lever system remains the same. Obviously, too much rotation away from seat tube angles found on diamond frames will change the effects of gravity enough to be noticeable. The horizontal component of the peak pedal forces may become large enough to overcome the frictional forces that help keep you in the saddle. Some mountain bike riders used to complain about how the 69-degree seat angles on the old Ritchey-type bikes made them feel like they were always pushing themselves off the saddle. On the other hand, too steep a seat angle puts too much of the rider's weight on his arms and shoulders.

I feel that proper fit should involve more than a good seated position. A good cyclist uses a variety of riding positions, including two different out-of-the-saddle positions - one for sprinting and a slightly different one for climbing. [Well, a range of positions for climbing depending on the steepness of the climb -- John Allen]. The rider's center of gravity (CG) over the pedals changes among all three positions; good overall bike position would assure that the rider is well balanced and does not have to expend excessive muscular energy in the arms and shoulders to support his weight in any of them. Also, there may be other factors that complicate fit, including unique anatomical characteristics and poor upper body strength. None of these considerations are served at all by the KOPS method. My alternative fitting regimen outlined below considers these factors as well as the standard requirements of comfort and efficiency."


(2) Steve Hogg on unweighting the upper body by finding point-of-balance / ideal setback with an indoor trainer (2011)

"The way to accomplish this is to have the seat set back the minimum distance behind the bottom bracket that allows the rider to cantilever their torso out towards the bars without unduly loading the arms and torso. You should need your arms, but only just need your arms. At low speeds there should be some weight on your hands but any hand pressure should not be uncomfortable. As road speed and intensity of effort increases the upper body should become progressively less weighted until at the limit, the rider should feel like their upper body is near weightless. My feeling is that the rider should be sitting a fraction in front of their centre of gravity."

(worth noting that Hogg and team's client base are primarily nonprofessional road cyclists aged 30+, which is the demographic I'm part of)

Carbonfiberboy 

Weight distribution doesn't matter. That'll be baked into your personal physiology, i.e. limb lengths, and the frame design. Here is my primer on how to fit your bike: https://www.bikeforums.net/21296948-post3.html

Do that. When you're done, your weight distribution will be what it will be.

79pmooney

Deleted. Not in line with intent of thread.

ctak

For example, framebuilder Dave Kirk's variation of the Bontrager / Hogg method (pasted below)

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( * let me first say that if you are a strong devotee of the KOPS deal then you will strongly disagree with what I’m about to share. I personally think that KOPS is as valid as standing over the top tube and seeing how much room between your crotch and the top tube. All one needs to do is look at the two fastest type of bikes out there – the new school time trial bike (knee way in front of the spindle) and a recumbent (knee more than a bit behind the spindle) to realize that this knee-pedal thing is crap. )

That said here is a way to get your ball park fore/aft saddle position. Note I’m not talking about reach from saddle to bars. Saddle to bar reach is a separate deal and should not be adjusted by moving the saddle fore/aft. Reach is a function of toptube/stem length.

1) put your bike in a medium easyish gear and ride up a very gentle grade. I use a 42-17 up a slight grade where I can maintain my natural cadence of 85ish without great effort.

2) put your hands on the tops of the bar next to the stem and ride relaxed like this for a bit. Let your body fall into a natural arch and relax.

3) now, with your body relaxed, lift your hands from the bars WITHOUT sitting up or changing the angle of your hips and lower back. Lift just the hands off the bars. Just and inch or so. Do not sit up.

3a) if you can do this without strain or by using a great deal of core strength then your fore/aft saddle position probably isn’t bad and is in the ballpark.

3b) if you have a hard time doing this even after a few tries then it’s a pretty good bet that your fore/aft deal could use adjustment. If you tend to fall forward when your hands are lifted it’s a good bet your saddle could go back. If you tend to fall back then your saddle is way too far back. The latter is pretty rare.

This test, like all tests is not absolute or perfect but I’ve found it to be a good general rule. I think more folks will find themselves falling forward (instead of backward) and need to move the saddle back. Most folks that have had a fitting that is built around KOPS will have a saddle that is too far forward and will put too much pressure on their hands (I’m still not talking about reach here). This will make folks want to fit shorter stems and to raise the bars. This will have the double negative whammy of making the bike handle like **** and make you want an even shorter-higher stem.

By having the feet the right distance in front of your hips your ass and lower back muscles (the best ones you got!) can easily hold your position. You can try this right now in your chair while you should be getting some work done – sitting in your chair put your heels 6″ in front of the chair on the floor. Lean forward a bit. Easy as **** eh? Now move your feet back so the balls of your feet are under the leading edge of the seat and lean forward a bit. It’s takes much more core strength to hold this unnatural position. It’s the same basic deal on the bike. Your feet support you and the added weight on your feet can be put into the pedals. If you pedaled with your hands then having a lot of weight on them would kick ass.
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