Aero Versus Weight

I am not an engineer but I have learned how to listen to good ones.  Ever since most of us were bitten with the bike bug, we learned lighter was better.  As Shimano found out in the late 70s, teaching the value of aerodynamics is a hard lesson.

Here’s how the HED website states it.

Let's look at a few figures. Assume a rider uses a conventional bike over a 25 mile flat course time trial. He weighs 150 lb, his bike is another 20 lb, and he is producing 185 watts of power. The aero drag with this scenario would be approximately 6.5 lb using aero bars into a 2 mph headwind of between 0 and 5 degrees. With his standard bike, our rider's time would be around 1 hour 7 minutes and 38 seconds. If we reduced the weight of his bike by three pounds, that time would come down by just 3 seconds. However, swap the wheels to an aero design and the drag could be reduced to 6 lb. Even with the additional quarter pound weight of the new wheels, his time saving over 25 miles jumps dramatically to over 1 minute 30 seconds. No contest.

That's not a typo.  At speed, on relatively flat roads, 3 pounds only cut off 3 seconds.  Ever think about why all of the super high mileage cars look like bullets?  It saves gas.

losing 3 pounds only cut off 3 seconds

being aero cut off over 1 minute 30 seconds