It’s one of the most desired attributes for anyone riding a time trial, but one of the most uncomfortable things to achieve, holding and maintaining an aerodynamic position.  Here Josh Page of GMC Coaching gives his detailed input into the whole aero subject.

 

#justaskGMC:  Maintaining aero technique is notoriously uncomfortable.  Is there anything riders can do to help that?

 

This is an interesting question and quite a good one.  A lot of people believe that for Time Trailing aero is everything.  However, like everything else in cycling it’s a fine balance between comfort, power and aero.  Fortunately comfort and power fall in to the same category.  The most comfortable position for a cyclist is generally the most powerful, and the most powerful position is one where the muscles are under little to no stress and all line up naturally.

Power vs aerodynamics

 

A cyclist is in their most powerful position when bolt upright such as that reflected by a mountain biker’s position.  However since this is not very aerodynamic, and with the high speeds cyclists travel at, wind resistance comes in to play, so we need to lower the cyclist’s frontal area.  As we lower the frontal area of the cyclist we begin to put stress on the key muscles for cycling, Glutes, hamstrings, quads, hip flexors and all the fine postural muscles which include those up the rider’s spine, as these muscles are stretched or shortened by the cyclist adapting to a somewhat ‘unnatural’ position.  As this position gets lower and more compressed and into an aerodynamic tuck the ability for the muscles to work at full force and capacity becomes lower so the riders power output will decrease.

However, as the rider’s power decreases and they become more ‘aero’ they are rewarded by gaining a lower drag coefficient.  Think of this as the time trailer and flat lander equivalent of watts per kilo.  Climbers will measure the wattage they can produce for particular time periods by dividing it by their body weight.  Time trailers will measure their frontal area and surface area to work out how much wind resistance will affect them.  They will then balance this against the power they can produce in an aero position to find the most effective and powerful position for them, looking to gain as higher power output as possible with as low drag coefficient as possible.  This can only be measured in a wind tunnel, and is the reason why professionals will invest a lot of time and money in to wind tunnel testing where they trial various positions and equipment to see how it effects their drag and power output.

 

One position doesn’t suit all scenes

 

It is also important to realise that positional changes can have compounding effects.  Something that may be aero fast and powerful for a short period such as a prologue or a pursuit, may be drastically slow and un-powerful after 20-30+ minutes as the stress of being in that position has an adverse effect on the rider over time.  Likewise something which may be a tad slower in a short time trial may pay off down the line as you’re still feeling strong and comfortable after 20-30+ minutes of hard riding.

A great example of this is Tony Martin who famously changed his position to a more aerodynamic one over the winter, only to discover that this season he was a shade of the former force he has been over previous seasons.  After a disastrous time trial at the Olympics where he finished 3m18 down on Cancellara he decided to return to his previous position which he found more comfortable.  Martin was quoted as saying “Now, I feel much more comfortable again. One has to accept that the aerodynamics are not everything, but the comfort factor plays a very, very important role. If your body does not work well, then whole aerodynamics thing means nothing.”

Once you have found an aero position that gets the balance of comfort and aerodynamics, it is also important to work on your flexibility and also your core strength to enable you to better support that position and stay in it over the course of your race.  You also need to ensure you train a lot in that aero position to get used to it both physically and mentally.

If you own a power meter and you can’t afford your own wind tunnel testing session, you can do your own field testing by riding at a set wattage, ie try to hold 300w, on a flat stretch of road for 10-15 minutes.  Record your average speed and power as well as distance covered in the time frame for that stretch, make your adjustments to your position, then ride the exact same stretch of road holding the same power for the same time frame and see how the distance covered compares.  (You should also hold a sub threshold power that produces high speed but can be repeated multiple times).  Keep repeating this till you find a position that you are happy with, if your position is well balanced between aero and powerful you should travel further for the same power, and hopefully comfortably.  Once you have found your position you will need to test it under pressure by performing an all-out time trial, hopefully you have a week day TT series close by you can race to compare your new fast position against other riders.

 

Photo:  Eugene Bonthuys

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