flmasters-mirror: Guru Dynamic Fit System

Guru Dynamic Fit System – Bicycle Fitting – 2-10-11
Written By: Sandy Scott, Florida Master

On February 10^th, 2011, I had the incredible experience of undergoing a bike fitting on the new state-of-the-art Guru Dynamic Fit System at St. Pete Bicycle & Fitness, St. Petersburg, FL. The store is owned by Mark Yeager, a very well known Cat 1 racer and multiple Florida State cycling champion and state time trial record holder. Paul Fabish, a highly experienced bicycle fitter who is an expert in using numerous fitting systems, conducted the fitting. Paul has a Masters Degree in Sport Management and is a seasoned athlete and coach. He has competed in bicycle races from velodrome sprints to the Race Across America (RAAM). Paul is also an Ironman and Ultraman finisher. Paul has coached cyclists to national and world titles. He obviously has a unique perspective regarding the needs of the cyclist. Paul is an expert and has a passion for fitting people on bikes which he does full time.

My current Guru Cron’alu time trial bike is rather dated. It is a model that is no longer manufactured, and it is made of relatively heavy aluminum. I planned to upgrade to a more state-of-the-art carbon fiber bicycle. The mission for my fitting appointment was to determine which of the many time trial bikes available would best fit my body and physical needs for comfort. I had no intention to write about the experience. The plan was that, at the end of the measurement/fitting process, Mark, Paul, and I would determine the bike that would best fit me. Then, Paul would re-fit me to my current time trial bike to reflect the new position so that I could ride it until my new bike arrives. However the experience and the results were so incredible that I simply had to put my thoughts to paper to express my enthusiasm.

It is important to me that I make a statement regarding another fitting system – the Retul system. As many of you reading this are aware, I wrote a well-publicized, very positive review of that system. I stand by what I said in that article. Not only is the system an effective fitting system for most riders, but the expert fitter who worked with me is someone whom I have the utmost respect and admiration for as a person and as a bicycle fitter. Technology, however, continues to move forward and the system that I am about to describe has upped the ante in that respect. I will soon reveal something that the Guru fit system disclosed that probably could not be determined or dealt with utilizing other fitting systems.

Being a technical minded person, prior to commencing the fitting, I asked Paul some questions regarding the Guru system versus the Retul system and further questioned him about his background. Here is what he had to say in his own words:

“I think it important for you to make the distinction between a fitting tool, and a fitting system. Retul and the goniometers that I use to measure angles on the body are simply tools. Even the Guru Dynamic Fit Unit is a tool. My fitting "system" has evolved over the nearly 20 years and thousands of fittings that I have done as a bicycle fitter. It incorporates all of the information in the books I have read by scores of authors, and the Serotta (Basic and Advanced) courses, and the triathlon-specific Fit Institute of SlowTwitch (FIST). I use each piece of information, and each tool at my disposal, as appropriate, to help solve the puzzle of each unique person's anatomy. As we discussed, I am opposed to any database or set of tables that profess to create the ideal position without considering each individual as an experiment with the sample size equal to one. I don't think that anyone having had a Retul fit need be disappointed. As you say, technology marches on. Since there are only 10 of the DFU's on the planet, and ours is the only one in the southeast, it is certainly the new kid (tool) on the block!

On a time trial or triathlon bike, the critical parameter on each body is the hip angle; that is, the angle formed between the femur and torso at the top of the pedal stoke. Even Mark was overly compressed when I worked with his TT position yesterday. It is one of the most overlooked, but THE most critical measurement when setting up a TT or Tri bike. The more aggressive the aero bar position is, the steeper the seat tube angle needs to be.”

I think that one thing that becomes clear from Paul’s statement is that the best fitting tool in the world will only be as good as the fitter using the tool.

I must reveal up front that I am a major fan of Guru Bicycles, not only having been sponsored by the company in the past, but also as the proud owner of two of their custom bicycles, a Guru Cron’alu time trial bike and a Guru Geneo road bike. I’ve won 12 state time trial championships and broken five (5) time trial records on the former and won and one (1) state criterium and four (4) state road race championships on the latter. My significant other Rosie, also owns two custom made Guru bicycles on which she has won state time trial and road race championships and has set one state time trial record. I believe with all my heart that they make the best bicycles that one can own. Be assured that this write-up of my experience would have been the same had I not been sponsored – it is the facts that count. My only motivation for writing this piece is as an informative expression of my enthusiasm for the fitting system (and the fitter Paul Fabish), and a way of conveying my very positive experience. I also want to make people aware of this incredible system in that it is available only at Guru dealerships.

Of particular interest going into this test is that not only was the bicycle being fitted custom made to my exact measurements, but I had been fitted on the bicycle twice. Once by a chap who was trained by renowned cycling aerodynamicist and fitter, John Cobb, but more recently I was fitted on the same bike with the Retul fitting system. I was under the mistaken impression that when fitted properly on a time trial bike, comfort was simply not possible, and, in fact, mutually exclusive with optimal positioning on the bike. That was certainly my situation.

I seemed to be able to attain and sustain higher speeds on my road bike than on a dedicated time trial bike designed specifically for that purpose. Certainly an aerodynamic TT bicycle equipped with a Zipp 999 tubular wheel set (front Zipp 808, rear disk), had to be capable of higher sustained speeds than a road bike. When I would do intervals on the same strip of roadway under similar conditions as to temperature, humidity and wind speed/direction, my records reveal faster average times on the road bike. I assumed that I must have been missing something in that I surely could not be faster on a road bike than on a time trial bike on which I had won numerous time trial championships and set 5 state TT records! This fitting ultimately revealed the reason for my loss of efficiency on my TT bike, my successful racing on it notwithstanding. More on that later.

I was so uncomfortable on my time trial bike, that the most difficult part of interval training and racing was the discomfort I felt being on the aero bars versus the discomfort of my cardiovascular system and legs! I couldn’t wait to get off those aero bars. I often marveled at the sight of other riders cruising along seemingly in total comfort on their time trial bikes – something that I have never experienced. The discomfort was so intense, that even during important championship races, I would often have to come off the aero bars momentarily due to my forearms cramping and the tightness in my shoulders. I found both to be rather distracting when I was trying to concentrate on holding a high level of performance. I might add, that I am talking about relatively short 20-kilometer time trials. I also believe that to race effective time trials, one must put time on the time trial bike due to the phenomenon of muscle memory. Mine was so uncomfortable that I used it only for interval training and racing.

My situation was further complicated by the fact that I broken my neck in a time trial race at the end of 2005, and I still suffer residual pain and immobility due to scar tissue and arthritic involvement in my upper cervical region. I continued to believe that my discomfort was normal supported by the fact that a teammate of mine who is a world champion time trial rider revealed to me that his neck and shoulders always hurt after a session on his time trial bike. If inherent pain on a TT bike is good enough for a world champion, it was certainly acceptable to me. I continued to ride in pain and discomfort.

Here is a picture of the way I used to look on my time trial bike. To put this picture in perspective, it was taken after I had passed my 30-second and 1-minute men in a state time trial championship. I was actually en route to breaking a state record with this miserable position – you could use my angled back as a launching pad for a skateboarder, and I’m sure that my wide arm position didn’t enhance my effort:

I recall when Guru first began development of their fitting system. The plan was to have a unit at each Guru dealer with telemetry to the factory where upon completion of a fitting, they could literally immediately start building the customer’s custom bike from the data obtained. The design philosophy was to allow the fitter to make decisions independent of bike geometry and therefore find the ideal geometry for each client to be built into his or her custom bike. That could be accomplished on the fly through the use of precision Kollmorgen electro-mechanical servos that allow attaining any possible position and replicating any tubing angle. Apparently, the process of developing a machine of this sophistication took longer than anticipated and after years of development, the units finally started appearing at Guru dealers very recently.

The machine itself is an amazing piece of engineering. Below is a picture of the unit without the various computer screens and ancillary equipment that are also part of the complete package:

The fitting machine can be set up to exactly replicate all dimensions of your current bicycle for those who bring in a bicycle for a fitting. Even the exact seat tube angle can be programmed into the machine. The fitter has a large array of popular seats and pedals; hence when you climb on the machine, you are literally sitting on what feels to be your exact bike. For those who start with no bike, the initial setup is determined by an extensive set of measurements taken of the subject’s body and a thorough interview dealing with any medical issues, injuries, goals, current level, etc., that precedes the measurement-taking session. The ultimate goal of my particular fitting was to make me as fast as possible on my time trial bike, and ideally enabling me to be as comfortable as possible in an aggressive, aerodynamic position.

Paul spent a solid hour measuring numerous parts of my body including having me stand on a pad that revealed the anatomy of my arch. He also tested my level of flexibility – something that is important to achieve aggressive positioning on a time trial bike. He even gave me suggestions as to the most efficient means of achieving cycling specific flexibility by demonstrating movements that I could practice at home. He was very thorough during the interview process.

My bike was mounted on a trainer equipped with a wattmeter set up adjacent to the fitting machine. There was a liberal use of video and still photography utilized throughout the process such that I could not only monitor my position in real time but also see myself after each change. Adjacent to the real time video were still shots of previously tried positions for immediate comparison.

The fitting started with me pedaling on my time trial bike with Paul observing. I was able to watch myself on a video and monitor various changing parameters on two large screens in front of the fitting device. Paul asked me to unclip my left foot and pedal with just my right foot to get a feel for my pedaling efficiency. I was literally unable to accomplish the test in that my stroke would actually pause with each rotation.

Paul took various measurements of me on the bike and immediately noted that my hip angle was too great. He also noted the tightness in my arms and shoulders and my excessive movement on the bike. My position was such that I was actually compressing my chest, hence not breathing as efficiently as I was capable of doing. Not a good situation in an event where one needs to take in as much oxygen as possible.

Paul noted that the position of my shoe cleats were not in the ideal position and he changed the position on both shoes prior to moving on to the next phase of the testing. As an aside, I have often noticed that when I look down at me feet, my right foot is often pointed inward unlike the left, which tracks straight. I always consciously move it to the proper position. The day after the fitting, I noted that not once did my right foot track incorrectly – something, which diminishes stroke efficiency.

Prior to the start of the testing, Paul measured every parameter of my bike and programmed the Guru fitting machine to exactly replicate my bike. Upon completion of the work on the bicycle, I climbed aboard the Guru fitting machine, which not only felt exactly like my bike, but was also equipped with exact models of my seat and pedals. With every fitting system, with the exception of the Guru device, if the fitter wants to change something during the fit such as movement of the seat, adding or subtracting a spacer, changing stem rise or length, etc., the person being fitted must get off the bike while the fitter makes the change(s). With the Guru system, these changes occur within in seconds with a simple input of parameter change by the fitter. The fitter on the Guru system can change any parameter very accurately to one millimeter. There was one request that I made that necessitated my getting off the fitting machine – I wanted to try other seats than the one that I had used for years. Paul, however, was able to quickly install each seat that I wanted to try.

Paul instructed me to begin pedaling and conducted some of the same measurements that had been accomplished on the bicycle. I repeated the single leg-pedaling maneuver with the same bad result as described previously. Paul then began changing parameters of the Guru machine to find my ideal, most aerodynamic position. By simply inputting data into the operator’s panel, Paul was able to immediately change any parameter of the bike on the fly. Various positions could be stored in the computer for later recall. He maneuvered the position to put me into a more efficient hip angle, and moved the seat down and forward from my current position. Also subsequent changes were done maintaining the desired, efficient hip angle. He also effectively lowered the front stack height on the fly – something that would be quite time consuming on other systems. As an aside, the Guru system allows the person being fitted to try alternate aero-bars if a comparison between models is desired.

The result of that initial change immediately manifested itself to me in the form of much more comfort. I had always experienced soreness and pressure in my perineal area (crotch) on my time trial bike - I now felt little pressure there. My forearms, which had felt considerable strain, now felt none. My shoulders, which had been very tight, now felt relaxed. I was no longer “white gripping” the aero bars as I had been previously.

Paul showed me the difference both with video and still shots and the difference was dramatic. Part of my issue was that my initial position had me reaching out to grasp the aero bars. My new position has positioned me over the aero bars that now support me and take the pressure off of my perineal area. I was able to watch numerous real time parameters on a large screen in front of me, which revealed data on both legs (among many other things) both in digital and bar graph format in real time. The bar graph was particularly interesting in that it revealed immediate differences between the pedaling efficiency and work being done by each leg. Initially, my left leg was totally overpowering my right.

Through tweaking, we evened out the effort between legs, and I could watch my pedaling efficiency number climb. After much experimentation, Paul finally achieved what he thought was the ideal position for me. Note that I said “for me,” – not for you and not for Dave Zabriske (many time national time trial champion). I’d love to look like Zabriske on the bike, but I neither have the flexibility nor neck mobility (due to a neck fracture 5 years ago) to achieve that position.

Paul constantly gave me great coaching advice on techniques for holding proper body position, etc. He finally asked me to perform the single leg pedaling drill again, and amazingly, I could pedal efficiently with one leg indicative of the fact that my new position allowed a much more efficient pedaling stroke. The big surprise was yet to come.

For the first time since I climbed aboard a time trail bike, I felt that I could ride for prolonged periods in the aero bars. My assumption was that Paul had simply placed me in a less aggressive, less aerodynamic position to enhance my comfort and I was not going to be as fast as I previously had been. I had not been paying much attention to where my position was moving from and to, just how I felt as the positions changed. Much to my surprise, Paul revealed that I was now in a much more aggressive, lower position than when we started. To jump ahead a bit, Paul had to remove a spacer from the head tube of my current time trial bicycle to get my position on my bike to the optimal position determined during testing.

Paul said, “Now I am going to give you a very graphic demonstration of the difference between your old position and your current position.” He pushed a button, and the Guru fitting machine moved to my original position. I could not believe it. I could literally not pedal the bike properly. My butt was moving on the seat and my forearms and shoulders started tensing up immediately, and I commenced using my usual death grip on the bars. I was feeling that old perineal pressure and my chest was compressed. I said to Paul, “This certainly cannot be my original position - I can hardly ride this bike.” He directed me to get off the Guru machine and climb aboard my bicycle, which was still sitting on the trainer. I couldn’t believe it, when I started pedaling the bike, I felt like I could hardly ride it, and my arms and shoulders immediately tightened up. It felt exactly as the fitting machine felt when Paul returned me to my starting position. That WAS the position that I had been riding my time trial bike!

It became totally clear as to why I always perceived myself to be faster on my road bike - I truly was faster! A recent time trial that I entered using my road bike generated a faster time than I could have done with my time trial bike, which is not exactly the way the system should work. Again, I assumed that I must have been missing something, but faster is faster!

Paul showed me videos and stills of my final position versus the position that I had been riding my time trial bike. I can tell you as someone who has a degree in aeronautical engineering that the after picture was of someone producing less aerodynamic drag then the former picture, not to mention my now more efficient pedaling stroke. In other words, I was looking at pictures of a person who was going to time trial much faster, AND more comfortably! I can tell you to a certainty without empirical data to prove it; I am now faster on my TT bike.

When a person is being fitted on a bike already owned or just purchased, upon completion of the fitting process, the fitter makes the appropriate changes to the bike to replicate the exact position found to be the most efficient using the Guru system.

The complete process took about three hours. Most of us cannot afford the incredible high price and travel time needed to undergo fitting in a wind tunnel. Apart from a wind tunnel, there is no system that can come close to this new system developed by Guru. If a customer decides to purchase a custom Guru bike, the machine, in conjunction with the extensive bodily measurements taken, allow Guru to build that customer a bike that will fit like a glove out of the box with zero compromises in geometry. For someone who simply wants an effective, expert, best-available fitting that one can possible achieve, this is the system to accomplish that mission - particularly in the hands of an experienced fitter like Paul Fabish.

Here is an example of where this newer technology stands out from the crowd of other fitting systems. The bike that I was primarily considering through a sponsorship has a seat tube angle of 78 degrees. We are each an experiment of one, and the Guru system revealed that the ideal seat angle for my body is 82 degrees. If I were to be fitted to the bike with the 78-degree seat tube angle, compromises would have to be made to get me close to my ideal fit – something that would be difficult or impossible to achieve. It’s true that certain changes can be made in the seat post in an attempt to get a proper fit, at least as it pertains to seat tube angle, but the ideal is to start with a bike that fits the rider – not to make the rider fit the bike.

Probably a great example of that is the experience of my fiancé, Rose Marie Ray. She has a custom-made, Guru Cron’alu time trial bike like mine. She wanted to get a new road bike that was carbon and it was close to the time she was competing in her first senior nationals. She tried to fit into women’s specific bicycle designs of two different manufacturers, being assured by the sales person in one instance that the bike could be adjusted to fit her. It just never happened and she had physical problems from being stretched too far over the bike. She ultimately sold both bikes and purchased a custom-made Guru Praemio titanium bike that fits her like the proverbial glove.

When I consulted with Mark and Paul after the fitting, they were both of the opinion that a custom-made Guru bike would be best for my particular needs. I had had some recent conversations with Guru, and a quick phone call from Mark arranged for a sponsorship for me with Guru, and they will be building me one of their state-of-the-art, incredible 901 time trial bikes.

The reader should understand that a bike fitting is a dynamic, continuing process. Things change. We become more or less flexible, we get injured, our bodies change in other ways, our riding goals change, etc. Some of my teammates, who have had wind tunnel fittings, have returned to the wind tunnel to have their fittings tweaked. Typically after a fitting, the person fitted rides their bike for some time and returns for any needed adjustments that might be revealed during extended riding. Often, as we gain more riding experience and flexibility, we are able to assume a more aggressive stance on the bike. Advanced riders might never need a post-fitting adjustment if they continue riding the same bike with the same equipment.

If you are anywhere near the Tampa Bay Area, I suggest that you stop into St. Pete Bicycle and Fitness, 1205 4^th St. N., St. Petersburg, FL, 727-894-7746, and say hello to owner Mark Yeager and meet expert fitter Paul Fabish. You’ll want to see this magic machine, and if you want to ride at your potential, consider a fitting with Paul. Their website is:

http://www.stpetebicycles.com/

If you are not in the Tampa Bay area, you can find your closest Guru dealer on their website at:

http://www.gurubikes.com/enUS/main.php

Below is the link to a YouTube video depicting segments of my fitting showing the transition from the uncomfortable position I started with to my now more aerodynamic yet more comfortable position:

http://www.youtube.com/watch?v=G5Ovu5_dMYA

I thank you Guru Dynamic Fit System and Coach Paul Fabish, but my competitors are not going to like you – especially when I show up on my new Guru 901 fitted by Paul Fabish!

Sandy Scott

www.brokennecktobrokenrecords.com
pedalmasher@gmail.com

Copyright Sandy Scott, 2/14/11 – Reproduction of this article is prohibited without express permission of the author.

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