|ADJUSTING YOUR SADDLE TO WORK WITH
You have already read many articles and seen photos on how the saddle is positioned to work with aerobars. You may be confused due to many opinions some of which are either conflicting or unclear. This article will take some technically difficult concepts and explain them in a clear simplified way. We will focus on correctly adjusting your seat to work well with aerobars. To start with anything else is like designing an automobile engine around a chassis.
With aerobars the rider tends to move forward approximately 1-2 inches from where one would ride with drop bars. The body is connected to the bike by three points of contact; feet to pedals, saddle to rear end and hands to drop bars or elbows to aerobar pads. Aerobars change the way your body is connected to the bike and therefore can have an affect on saddle position. When resting on aerobar pads the forces on the rider change slightly compared to drop bars. When riding, the body wants to assume a position on the saddle such that the body is in equilibrium. If you are not in equilibrium on the saddle you must compensate by either pushing or pulling on your handlebars. It is best to be totally relaxed on the bike and let your legs do all the work.
A good way to test out this concept is to ride in the aero position and lift your elbows off the armrests (figure 2). You will notice a tendency to slide back in the saddle due to an increase in force back. Your saddle position can also be affected by other facters such as changing from aero bars to drop bars, moving the aerobars back, or raising the stem. These changes in positioning affect the forces on the body slightly. Whether changing saddle position due to aerobar changes is effective depends on whether the rider is more powerful.
I would recommend this approach to riders new to aerobars because it subjects then to the least amount of change.
Even though the body tends to move forward due to aerobar positioning, it is HIGHLY DEBATABLE whether the legs can apply more or less power to the pedals. The rider should experiment with the position of the saddle and find out what works for you.
From my own experience, the seat height is far more critical to rider power than whether the seat is forward or back. To prove this set up your saddle so you can comfortably move back and forth about 2 inches. Be careful to set your saddle so the relative height to the crank center is not affected by you moving back and forth (tilt your saddle up slightly). Ride forward for about 1 minute and then slide back for the same time. Pay attention to your pedal stroke and how it changes. If you can be efficient in both positions you will find that it is best to alternate positions in order to use different muscle groups for short durations. It's like standing out of the saddle for a quick jump, you generate more power but only for a limited time.
Another factor is that by having your back flat (good aerodynamics) and seat back (tradition), the body tends to be cramped while padalling. This is what has been called pelvis rotation. Moving the seat forward helps reduce stomach cramping by increasing the angle that your body forms. Stomach cramping can be reduced by tilting your back up, but here aerodynamics is sacrificed.
Now that you understand how and why aerobars affect seat
position we can go back to positioning your aerobars.
1) Don't be so stretched out that you tend to pull forward on the seat
2) Keep your hands in narrow
3) Keep your back flat
4) Keep your elbows in narrow but don't constrict breathing
5) Adjust your position on the bars as you slide back and forth on the seat to maintain optimum aero position by keeping your elbows on the pads as close to your knees as possible.
The fastest position is achieved when the rider has the least amount of wind drag and can apply the most power to the bike. At 25MPH ninety percent of the cyclist energy goes into wind drag and eighty percent of the wind drag is caused due to the body. At faster speeds body position becomes more important. However body position must not affect the way the body transfers power to the bike. Body position can be improved by the following simple tips using aero bars.
The elbow should be placed at the proper height, width and distance from the seat. The proper height insures that the rider has a flat back minimizing frontal area of the body. The correct distance from the seat occurs when the elbow is comfortable on the armrest and the elbow is close to the knees during normal riding. To achieve this the proper length of the stem must be used. On the other hand, being too stretched out will decrease rider aerodynamics but may make it easier to breathe. In addition, being too stretched out will make the rider slide forward on the saddle. Correct saddle position must be determined before pad placement. One must experiment to find out what works. The proper width is as narrow as possible without affecting either steering control or breathing.
If one is broad shouldered and prefers the pads wider it is best to hold your hands close together on the bars. This allows greater stability, good breathing and good aerodynamics. Holding your hands wide will allow air to go thru and hit your stomach, increasing the parachute affect. If you are comfortable with having your elbows in narrow you are more aerodynamic but may find it more difficult to control the bike. A good rule of thumb is to have your elbows directly in front of your thighs. This generally will maximize aerodynamics and control.
Hand position is not nearly as critical as elbow position. However for greatest efficientcy, the arms should be close to straight and as narrow as possible. The orientation of the hand is one of personal preference.