As a bike fitter that specializes in triathlon fitting, I feel there is a common misconception about how much “drop”, vertical distance from your seat to the aerobar pads, you should have.  We have fixated on a few fast riders who appear to have radical positions with tons of drop.  This reminds me of the checkout counter at the grocery store where you see all the computer fixed women (sometimes men) who are setting unrealistic societal beauty or fitness ideals.  We will always set ourselves up for failure if we set out to look like the people on the magazine covers, and the same goes for trying to get as much drop as possible to be “fast” and to make it “look” cool.  So what is the right amount of drop for you?

I want to first talk about what the drop means.  To understand drop, it is important to know that aerobars were designed to put you in a more stable aerodynamic position.  Being more aerodynamic means that you will either get from point A to B faster for a given amount of energy, or you will be able to cover that same distance more efficiently (less energy) in the same amount of time as it would take without the aerobars.  The key factor relating drop and aerodynamics, is that lowering the bikes front end can decrease the frontal area of the rider that the wind is contacting, thus, making you more aerodynamic and faster (I spent a lot of time with this in my Masters research).

So more drop is obviously better. Right?  It turns out that more drop is not always better.  First off, just because you can get lower in the front end, it does not always mean you are more aerodynamic.  When you get too low relative to your flexibility, you get more rounding in the back which actually changes the shape of your body relative to the wind and affects your aerodynamic quality in a negative way (alters the shape coefficient of the aerodynamic equation – FD= ½*ρ*A*Cd(v)).  Second, with to much drop, your hip angle starts to close and this can lead to a loss of power.  You may also tighten up more easily in these lower positions, causing you to sit up and stretch, which vastly compromises the small aerodynamic gain you may have created by having slightly more drop.

So what determines the amount of drop for an individual?  The main factors that set up drop for an individual arranged in my level of importance are:

• Injury – past or current injuries may affect the bodies potential for accommodating drop, or aerodynamic positions altogether.
• Body proportion – one example is having two identical bodies except the arm length.  Having longer arms will mean more drop
• Flexibility/Range of Motion (ROM)  through the neck, back, hip, and hamstrings – if you have limited ROM in the cervical vertebrae, you will have less drop
• Seat Tube Angle (bike geometry) – changes the hip angle which affects how well we can produce power.  So moving the saddle further forward (to a point) we can often have more drop
• Event distance – the longer the distance, the more comfortable we need to be and the more likely we need to have less drop to keep from tightening up, prematurely fatiguing muscles, and be able to digest more easily.
• Goals – may determine the need for more or less drop mostly dictated by physical comfort and riding confidence level (safety).

As you analyze your current bike or you are trying to set up a bike for yourself, make sure you don’t just set the bike up to mimic the bikes you see pictured in magazine ads or your favorite tour rider.  This will set you up to have a bad experience on a triathlon/TT bike, and possibly just perform poorly on race day.  There should be more thought and reasoning behind the amount of drop you choose rather than just deciding that you want a “flat” stem with no spacers.  We pride ourselves in understanding the nuances of fit which encompasses the amount of drop an individual should have.  Feel free to contact me for more questions on this topic, or to set up a professional bike fit, and take the guess work out of your bike setup.