Technology: Wheels, Watts
It was a pretty day, a light westerly breeze blowing the hot summer air out over the waters. All along the docks there were wives and loved ones crying and holding their loved ones until the last moment. As the very last few moments came there were pleas and shouts of fear that these sailors would never return. These brave young men were embarking on an adventure that was doomed, guaranteed to fail. The wise men and the scholars had all spoken their positions and there was no real hope, everyone knew this was the wrong direction to go. These adventurers were off to discover new worlds, but first they had to break over the edge, the edge of the earth because everyone new that the earth was FLAT.
Technology has a way of making our lives uncomfortable. Technology can seemingly complicate and confuse our lives. But technology will always reveal the truths about objects, forcing the adventurers into more exploration.
A few months ago I wrote an article about how Aero seat posts donít work. On the surface thatís a pretty big statement to make and since I had long been a proponent of all things aero and aero seat post in particular, those were some hard words to type. Certainly if there is not a rider on the bike then a thin aero post does work well. But don't forget, we must have riders to ride our bikes and that changes things a great deal. There are several of us that continued to study this area and we are learning a great deal about specialized air control around the rider. And with potentially new discoveries on the horizon, we now have a new direction into which to look which has forced us to explore the relationship of the aero seat post verses the rider's positioning. And as we research and discover new data we can then provide you, the consumer, some insight into this issue so that you make better purchasing decisions.
I have been going to wind tunnels for more than 15 years now to study bicycle air flow. I have made every mistake possible, made most of them twice, but have continue to push on and learn about how to make a rider go faster. One of the biggest ingredients that Iíve found for aero success is a willingness to admit failure, the strength to believe in something, develop it, test it, and then get your feelings hurt when itís proven wrong. As Iíve continued to study different parts of the bike, the one area that always looms as very important is... wheels.
Wheels. Without wheels youíre not going very far. Wheels are so interesting yet so confusing to cyclist. Thereís a variety of shapes and configurations and there is an ocean of difference in price between two objects that appear pretty similar. If you take the money out of the equation and just look at the technical aspects, it can get overwhelming. If you throw in some marketing hype that is almost never backed up by research, then wheels can become downright intimidating. I began trying to show the difference in wheels by expressing the energy they require to spin through the air in watts. Watts are the amount of energy a human can generate over a given distance and since we, as humans, have difficulty generating very many, we need to use them carefully. Originally and still to this day, we talk about wheel drag or the effort it takes for air to pass over a wheel. Wheel drag can only be measured in a wind tunnel and wind tunnels are expensive and not readily available for people to use. Drag numbers are also hard for riders to relate to because these numbers are affected by everything around the object. Loose clothing, long hair, tube sizes and shapes all affect this drag number. Watts generated by wheels are not affected by these outside factors so that makes it a better way to express good, bad, or better. Over the years, Iíve continued to try and enlist the help of various manufacturers to learn about wheels and pay for some of the wind tunnel time. Most of the manufacturers are very hesitant to get involved because it gives their competitors all the information for free and they canít seem to get past that.
One company, Hed wheels, did jump on the band wagon early on and has continued to stay heavily involved in wheel research. Steve Hed has always been an open book to the athletes and to his competitors, trying to convey the most accurate information. Very few companies have spent the time or money to develop products in this way. It's the been a long hard road but it has led to great success for Hed wheels.
As I said earlier, watts are something on which we need to focus. The engineers at Texas A&M have been working with me for the last 3-4 years to develop a way to consistently measure wheel watts. My last trip to the wind tunnel was in Sept. í02 and it was like sailing off the edge of the earth only to discover that the earth was round. I believe we have conquered wheel watts and how to measure them correctly. This would normally be cause for great celebration, big fireworks and much partying, except that as usual with all things in research it trashed everything I thought I new. The next step will now be to find a way to express watts/drag and steering torque in simple terms that means the same thing to everyone. When we solve that equation, and hopefully very soon, all or you will benefit a great deal. Iím hoping to come up with an "Energy Value System" that will take into account the drag / steering torque/ watts and give a value verses price that the industry will maybe adopt.
Technical adventures are a lot like the old sailing adventures of Columbus and others. You make some mistakes, you run aground every now and then, but eventually, you find a new world.
Train Hard and be well