Pay It Forward (pun intended)
 

In the spirit of Darth Lefty's thread on aerodynamics. I would like to inform the forum about a matter knee and dear to my heart. Saddle position. Specifically, the fore-aft location of the saddle, relative to the handlebars. From many, many posts in the very forum, over the years, a number of you use this dimension to adjust how much weight is placed on your handlebars. Posters complaining about numb hands are routinely advised to scoot their saddles backwards and this will improve their body position and thus relieve their numb, unresponsive, fingers.

I'm not going to argue this point. What I will say is this: a bicycle has potentially adjustable handlebars, stems and saddles. The saddle adjustments were intended for the optimization of power transfer from your body to the pedals. Any effect on hand comfort is incidental, and consequently should not be relied on as a best practice for achieving said comfort. Especially if it compromises the primary reason for saddle adjustment. Hand numbness is best addressed by adjusting handlebar height.

As your pedal rotates through its 360* circle, the point of maximum power transfer is the 3 o'clock position with the pedal moving downward. You want the main shaft of your shin to be as nearly vertical as possible at this point. If you have your saddle shoved backward as far as it can go, especially since most saddles have an inch or more of setback already built in to the design... this can put you seriously out of pedal power contention. You just aren't getting all the efficiency you could. Worse, you are now stretching for the handlebars. You didn't go out and buy a shorter stem because you moved your saddle back, did you? Of course not. So you unconsciously scootch forward on the saddle to reach the bars and thus sit forward of the part of the saddle meant to receive your taint, and even the most well designed anatomic saddle on the market cannot always compensate for such gross abuses of application.

The vast majority of the readers of this forum are males over 5'8" in height. We are sitting 30" or more over the bottom brackets of bicycles with a 73* slope to the seat-tube. Our hip joints are well behind a vertical line drawn through the bottom bracket and even further behind a vertical line drawn through the pedal spindle of a pedal in the three o'clock forward position. When in doubt, do not further increase this distance without having a good reason why. Hand pain is NOT a good reason. Knee pain? Well, now you're talking, but, I submit, if knee's are aching, a decrease in the distance to the pedal is likely the thing to try first. KOPS- Knee Over Pedal Spindle. I'm a believer. Set your saddle height first, get your knee over the pedal spindle and then put your handle bars a comfortable distance away. I like mine so my middle finger can just reach the bars with my elbow on the nose of the saddle. This isn't scientific it just is a dimension I can transfer to other bikes I may ride. Handlebar height can be anything from seat height to 2" above seat height. This is with flat bars.

The important takeaway is that saddle position should be used to control your power delivery and knee comfort, and handlebar/stem adjustments should be used to control your upper body and hand comfort. If something hurts, don't be stoic. Fuss with your fit until the pain goes away. Commuting shouldn't cripple. That's all I've got. For now.

H

Everybody sell their recumbents! You'll never be efficient!

While I believe that KOPS is a good starting point (and I believe that there are far more cyclist that are suited to it than not), I don't think that it should be gospel for all cyclists. There are lots of different body types, and for me, having a balanced center of gravity was more important to comfort and longevity than wrote adherence to KOPS.

Just a guess... but I wonder... if you viewed a recumbent rider's relationship to the pedals, from a recumbent perspective. With the leading pedal in the 12:00 position... might you not find a similar relationship to KOPS?? Hmmmm...

H

I think you are wrong. They are interrelated and have to be considered together. Power transfer is affected by a combination of saddle position and forward lean. If you want to lean forward, you move the saddle back. If you like to sit upright, you move the saddle forward a bit (and raise the handlebars). That way you use your upper body weight to increase your downward pedal power. When sprinting all out, in a low position, you can even pull up on the handlebars to add power.

If people feel too much weight on their hands, they have three choices. Sit up, slide back, or pedal harder.

I'm all confused now, seriously.

Here again I disagree. If your knee is aching, it is either because you are grinding instead of spinnng (so drop down a gear or two) or you are too close to the pedal and transferring power when your knee is too bent (so move your seat either up or back). Rarely you might have a sore knee due to too much extension, but much more likely due to too little.

Yes, you would, and that is exactly my point. The recumbent example just illustrates that any position rotated around the bottom bracket has an ideal knee bend. So whether you are in a "tri" position with a very steep seat tube angle, or a recumbent with a very shallow seat tube angle, there is still an ideal position. A centimeter or two off of KOPS, in my mind, is no different than one of the extremes.

Sheldon Brown explained the seat position issue well. If you are standing and bend forward at the waist, like a someone poised to dive into a pool, you have to move your butt backwards to balance your upper body. If you were to lean forward with both your heels and butt against a wall, so your butt can't move back, you would fall forward.

So if you like to ride leaning forward at 45 degrees or more, you need your seat farther back than someone who rides sitting fairly upright, so you won't be "falling forward" onto your hands.

Bingo. Thus, there is a golden arc of seat post height/saddle setback that extends from forward and (relatively) high to rearward and lower. In the past, after brief layoffs from riding, I would set the saddle forward/up on the arc and, as my abdomen got back in shape, would lower the saddle and move it back. I never found any reason to adjust the stem length when making these changes.

I feel your pain. Give the KOPS thing a try if you are having a less than outstanding experience on your commute. A ten mile commute kind of forces you to try to get the most bang for your calories expended. Spinning at an efficient cadence is much easier when your body is in an optimum relationship with the cranks.

H

Most people do not consider the "arc" and what you end up with is knee's that are hyper-extended when the leading pedal is furthest away from the body. Trying to apply power like that can kind of work but its like using the multi-tool in your Jersey Pocket to torque your crank bolt. It can work... but the 8" wrench at your shop at home (or your LBS) makes the job effortless. With modern seats people aren't a few centimeters out of KOPS they can be inches out. They are working harder than they need to be and totally unaware of that fact. Even if having a more open knee does less damage than a more closed knee, the best practice is a 90* knee or closer to that than not. When you want to shut a stuck window you move as close as you can and shove down. You don't stand way back at arms length and try to get the window down with your arms extended full length. That's a gross example of what is taking place at a much more subtle level.

H

I'm kind of lost with all the adjustments. I'm now waiting for a stem I ordered monday. The thing is when I change something, one thing on the bike, it affects everything so I'm never sure of what next step should be. I tried two different LBS for a pro fit with no satisfying results. At 60$/hours to fit me no better that I did myself I'm now experiencing with the adjustments on my own.