Aero Bars

Wind resistance is a not-so-funny thing.  What makes it so devilish is that it actually gets greater the faster you travel.  It is almost like the wind is penalizing those who are the fastest the most.  Not only does it increase with speed, but it increases exponentially!  So if you double your speed, your wind resistance will increase four times (two squared).  If you triple your speed, your resistance will go up by nine-fold (three squared).  To overcome the wind resistance the cyclist must generate power equal to the wind resistance times the velocity.  Therefore, the power needed is the cube of the change in velocity.  So if you double your speed, you will need to increase your power by eight times (two cubed).

At around 20 mph, wind resistance makes up 90% of the total resistance.  At 25 mph, it makes up almost 100%.  As a result, streamlining is extremely important.

Frontal Surface Area And Shape.  Although wind resistance is primarily affected by velocity, it is also dependent on the frontal surface area and the shape of the object moving through the wind.  The larger the frontal area, the greater the amount of oncoming air that strikes the athlete and the move power is needed to get through it.  How big you are and the position your body is in will affect your frontal area.  Since you can't do much about your size, you must concentrate on your position.  Sitting straight up may feel comfy, but you will go much slower and have to work much harder to go fast.  Riding in a tucked, aerodynamic position will make it easier for you to go fast, so get aero bars!

Additionally, the shape your body is in will also have an affect on how easily you slide through the air.  Smoother surfaces create less turbulence and, as a result, less resistance.  Keeping extremities tucked in helps to keep turbulence to a minimum, which is another reason why aero bars are so useful.

Types.  Aero bars come in all shapes and sizes.  Talk to your local bike dude about the type of bars that will suit your needs and bike best.  Some key things to keep in in mind are:

  • Comfort.  You will be logging some serious hours on these bars, and if they aren't comfortable you will be regretting your decision every time you ride.  Try to test them out beforehand if you can and try to buy them from a place that will let you take them back if they start to rip up your arms or hurt your shoulders or back.
  • Weight.  For obvious reasons, try to pick the lightest possible aero bar set that still meets your needs.  For more on the effects of weight, check out the Resistance Archive.
  • Arm Positioning.  You want an aero bar set that brings your arms in tight to your center line and allows your back to get flat and low--all while maintaining your overall comfort.  Some of the first aero bars left your elbows, and subsequently your arms far out on the sides.  This causes your upper body to act like a parachute in the wind, which is not good.  It also is important that the bars do not position your arms too far forward or backward.  You'll know if its bad because it will be uncomfortable for you.

Trunk Comfort.  A final advantage to using aero bars is that by supporting your forearms and making your upper arms fulcrums for your back, you are much more comfortable than keeping an aerodynamic position without the use of aero bars.  You should be able to hold a tighter position for a much longer period of time.  You should also feel more stable on the bike.  If you don't believe us, ride your bike for a half hour with aero bars and then without aero bars and you will notice a huge difference in your comfort and speed.  "We guarantee it!"

The positioning of the aero bars varies, but should be done per the manufacturer's instructions and by your own comfort.  We do recommend, however, that you keep the tilt of the bars as close to horizontal as possible.  A tilt between 5 and 20 degrees is considered best.  Any tilt of more than 30 degrees has been shown to cause excessive drag.  See the Aerodynamic Position Archive

That's it.  Aero Bars are your friend, so get them and kick butt in comfort and style!