Saturday, February 10, 2007

2/10/06 - The Art of Bike Fit

Science: 2 a : a department of systematized knowledge as an object of study b : something (as a sport or technique) that may be studied or learned like systematized knowledge

Art: 1 : skill acquired by experience, study, or observation, 4 a : the conscious use of skill and creative imagination especially in the production of aesthetic objects

- Merriam-Webster

I believe that most people perceive the act of “bike fitting” as a science. An easy evaluation to make given all the measurements that are usually taken of the prospective rider: Height, inseam, arm length, torso length, shoulder width, etc. Then there are angles and tube lengths of the frame, not to mention terms such as rake, trail, and the somewhat abstract concepts of bottom bracket height and chainstay length. Enough to make your head spin? If yes, you’re in the majority.

With a tape measure, straight edge, calculator, angle finder, level and a good sharp pencil it is possible for someone to create good bike fit. In fact, I should state that these tools are necessary for very good bike fit. But, there is a difference between good bike fit, and a great bike fit. This is, what I would say, separates a bike fit scientist from an artist.

As previously defined, the world of science is one that adheres to laws, methods, systems; things that are proven. If you have studied art at all you know that it has it’s own set of laws, methods and proven techniques. All of these things must be mastered in order to be a truly great artist. But, what should also be noted is that some of the best artists know when to leave convention behind to reach their true objective: a masterpiece. Great art is created when the artist knows where to apply the rules and where to break them. Great art is creative science.

Most of what is used today as established standards for bicycle fit were originally concepts developed and used by NOCI, the National Olympic Committee of Italy. While there is little doubt that the Italians are true bicycle artisans – especially in construction – there is one flaw in the canvas, if you will allow the allegory. The NOCI studies were all based on young, athletic, flexible, and phenomenally fit males. At some time in an average cyclist’s life, they lack at least one of these attributes, if not several of them. If one or more of these attributes is missing, then the rider cannot assume the same riding positions. And so, the science applies, but art must create the masterpiece.

But, to go a step further, to try to put every rider into a traditional “racing” type position; like those outlined in the NOCI standards, is wrong for most riders. Take women for example. If you’re particularly perceptive, you’ve already picked up on the fact that I stated that the NOCI standards were designed around males. Even if you’re a young, athletic, flexible and phenomenally fit woman, the NOCI fit principles do not apply. The female body structure is so different from that of males that the same riding position is not only uncomfortable, but is also not maximized for efficiency. Therefore, again, we must apply the art of our experience, study and observation to achieve a riding position that is comfortable and efficient for the rider which we are working with – whether male or female.

A couple of recent fitting appointments of mine come to mind. The first, a woman who was getting her first road bike after successfully riding a comfort hybrid for years. Her fitness and flexibility were fantastic – and far above average for her age. However, other physical conditions dictated that even a contemporary “women’s-specific” fit was still a little to the aggressive side and caused discomfort in her shoulders and lateral muscles of her back and sides. So, by relaxing her position by slightly raising her handlebars (being careful to also maintain the handling characteristics of the bike – an item I’ll touch on later), we will be able to make her cycling experience more comfortable without sacrificing the efficiency she so much desired when considering a road bike or changing the handling of her bike. There is nothing about her riding position or component specifications that are “unorthodox”, however we could not use “traditional” (or NOCI) methods to fit her bicycle. To do so would result in her being quite uncomfortable on her bike and probably giving up the road bike and going back to her comfort hybrid; accepting, unnecessarily, it’s sluggish inefficiency.

My second client who comes to mind had met much frustration in his pursuit of a road bike that he feels fits comfortably and is enjoyable to ride. Riders in his situation have commonly been bounced around several times on different sized bikes and had to tolerate multiple attempts at comfortable riding positions, at the expense of their bike’s handling characteristics. The result being a bike that may fit better, but is no longer fun to ride.

Now; as I alluded to earlier, an aside: An important element of the art of bike fit; one which I feel is the most commonly overlooked, is the rider’s comfort while preserving the intended handling characteristics of the bicycle. To be fair, not everyone has the background of working with frame builders on both stock and custom designs and therefore being able to understand how all of these angles and lengths of tubes and stems work together to achieve desired performance and fit objectives. “O.K., Matt, you’re boring me. Why does all this matter?” Well, a bike that is comfortable to ride is, indeed, of the utmost importance, as you wouldn’t ride it if you weren’t comfortable. But, you wouldn’t ride if it weren’t fun, either, would you? Well, a bike is not fun to ride if the fit does not observe the originally intended handling characteristics. Stem length is where this most commonly comes into play. Without getting into principles that are not easy to convey in this context, I’ll just say this: If a bicycle does not have a stem of an acceptable length, it will not handle as it was designed to, and will not be as enjoyable to ride. Anyone can change stem length on a bike and change it’s comfort characteristics. A skilled bike fitter can change your bike’s comfort characteristics without sacrificing proper handling.

Which leads me back into my story. This gentleman’s difficulty in finding cycling nirvana was due to two different things: 1. For his height, he was very long-legged, having the inseam length of someone up to 4 inches taller than he. 2. Some flexibility limitations due to a slipped disc in his neck. Both of these qualities indicate immediately to the experienced bike fitter that this will not be a conventional bike. He had decided on his own that he wanted a made-to-measure bike this time around in order to avoid the unpleasant experiences in his personal cycling history. To address this fit properly is a case of having the right tools – in this case that tool is our Waterford FitMaster adjustable fitting bike. After taking body measurements and spending some time with my trusty calculator we were able to set up the fit bike and then make adjustments to achieve a comfortable fit that will also be physiologically efficient and handle properly. Then we hand off those dimensions to the frame builder; in this case it wasWaterford, to make it a reality. By taking some time, listening to the client, and not trying to put the rider in the box of “traditional” fit we came up with a real solution rather than simply providing a “band-aid” to a problem.
So, all this is to say that bike fit is equal parts art and science. If we concentrate only on the numbers, we ignore some of the intangible qualities that really personalize the bike to the rider. However, the science is important; and if we approach the fit process purely artistically, we ignore what the very laws of physics say must be true. Masterpieces happen when the right laws are observed and the right laws are broken.

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