Triathlon Bicycles – Do Slow Riders Save More Time? - http://triathlonbikesonline.com/triathlon-bikes/triathlon-bicycles-%E2%80%93-do-slow-riders-save-more-time/

|

Triathlon Bicycles – Do Slow Riders Save More Time?

Slow Riders improve more with Aero Equipment

Who benefits more from the use of Aerodynamic gear, a slow rider or a fast rider? For the sake of argument, let’s say that a slow rider rides a time trial at 18 mph or 30 kph and a fast rider rides at 25 mph or 40 kph.

Both riders have the same aerodymanic profile before and after implementing some aerodymamic peice of gear, let’s say, adding aerodymamic drop bars to their road bike frame. At this point, the physics of the riding can get a little complex, but the basic ideas are easy to follow.

As your speed on a bike increases, the amount of force you need to create in order to overcome the resistance provided by the air you ride against increases. With increasing speeds, come increasing forces. A faster rider spends more of her energy overcoming wind resistance than a slower rider.

The logical (but erronious) conclusion is that a faster rider would derive more benefit than a slower rider by implementing aerodymic measures such as drop bars, specialized tubing or helmet shapes, narrow arm profile, flattened back, etc.

So why, you ask, would a slower rider save more time than a faster rider with the use of aero gear?

Aha…that’s the key point is TIME savings.
Huh?

Think about it. In a race, the rider is concerned with not necessarily how fast she rides the course, but how long it takes to ride the course. Speed (miles per hour or kilometers per hour) is typically a secondary measure and is an afterthought when looking at finish line results. The overall time (hours, minutes and/or seconds) is what distinguishes first place from second plance and so forth.

I know what you’re thinking…

What in the world are you talking about Griffith?
In any given race, the bike leg is conducted over a fixed distance, say 20 k for an Sprint Distance Triathlon. The faster rider, going at 25 mph, is on the course for less time than the slower rider going at 18 mph. The first rider in this case would finish a 20K time trial in thirty minutes, whereas the slower cyclist finshes a 20k time trial in 40 minutes, a full 10 minutes later.

Now lets take both of those riders and give them some aero equiment, say switching from a standard road racing frame to a top end time trial or triathlon bike.

According to the math done by the folks at Cervelo, the speed gain by the faster cyclist is indeed more…a full 2 kph faster! And for the slower rider, the speed gain is significantly smaller, but still 1.4 kph faster. (These speed gains take into account the “speed squared” factor in calculating drag if you are doing the math at home.)

Revisit the 20k Time Trial Course
OK, now lets take these new speeds out onto our 20k Sprint Triathlon course.

The fast rider is now riding at 42 kph and the slow rider is riding at 31.4 kph…so who has a bigger time savings?

That’s right, it’s the slow gal that improves her time more…Over 20km, the fast rider finishes the bike leg in 28:34, a full 1:26 faster than her previous time. The slow rider is still slower, but finishes her leg in 38:13, a full 1:47 seconds faster!

The slower rider improved her time trial speed by 21 seconds more than the fast rider did!

If you’d like more detail about the math or figures used in this article, just stop on over to the Cervelo web site.

And