Sandy Scott is a multiple Florida, Georgia and national time trial champion across numerous distances. Sandy’s is an amazing cycling story: Now 72, he didn’t take up the sport until age 64, and soon afterward broke his neck in a time trial. He has, in one of his favorite phrases, been “kicking butt” since. Click to watch an interview with Sandy that tells of his ordeal, his recovery and his love of cycling.
What follows is Sandy’s report on a recent wind tunnel bike fitting he had done. Even if you’re not a competitive cyclist, it’s an interesting look into the process, and how small changes in bike position and equipment can yield extraordinary results in terms of saving power and time. Extraordinary is certainly a word that comes immediately to mind to describe Sandy Scott.
The subject of efficient bicycle fitting fascinates me from two perspectives: my educational background as an aeronautical engineer, and my passion for racing time trials.
My significant other, Rose Marie Ray, is a Florida and Georgia state time trial champion and Florida time trial record holder, and a silver medalist in the senior nationals sprint triathlon. Her last fitting was over two years ago when she got a new TT bike. I recently viewed photos of a time trial she did not long ago and saw that her aero position looked rather inefficient. In short, she had allowed too many people to give her advice on her position and she had slowly devolved to her current (bad) position on the bike.
The catalyst for my fitting in Speed Tunnel‘s mobile wind tunnel was the fact that I decided to give Rosie a bike fitting as a Christmas present to get her back to her winning position after a recent loss. She was fighting a headwind going to the finish and just could not get her speed up. I decided that as long as I was going to be there, I would also give myself a Christmas present of a wind tunnel fitting.
Other fitting systems like the Retul and Guru Dynamic Fit Systems are great, but the gold standard for fitting is the wind tunnel. Only the wind tunnel can accurately reveal the effect(s) of changes as minute as 1/8th of an inch (0.3 cm). In my particular case, I thought it would be a fascinating experiment to see what, if any, modifications the fitting would dictate in that I already had a very efficient, successful position on my time trial bike.
My last fitting, accomplished by a highly experienced bike fitter in St. Petersburg, Florida, was in the spring of 2011. Since that fitting, I had not lost a single race, won at the nationals, establishing a new national 5K time trial record in turning the top time of the day for all age groups, turned top time of the day for all age groups two years in a row at the Georgia Golden Olympics, and also set Florida state time trial records at 5K, 10K, and 20K distances. I had also achieved an incredible speed on the flats of Houston of 39.5 mph (63.6 kph) — downwind! In addition to my curiosity, I was a bit apprehensive in that I was well aware of the old adage, “If it ain’t broke, don’t fix it.”
The fitting was to be done by highly experienced, expert fitter, Roy Foley. He is experienced on both the Retul and Guru fitting systems and is a certified cycling coach and successful bicycle racer — all of which gives him a unique perspective.
At the beginning of the fitting, base drag measurements are taken of the rider on his bike as a reference point for any changes that might be made. Various “runs” are made in the tunnel, and the computer assesses the effect(s) of any changes that were made prior to the run. Not only can the bike and rider be measured for drag, but also the wind tunnel allows the testing of various helmets and skin suits. Interestingly, helmets test differently for each rider, enabling the person being tested to discover which helmet is most efficient for him.
In my situation, Roy found that my seat position (height and fore/aft) was perfect. There was a bit of adjustment room to move my aerobars closer together, but the wind tunnel indicated that there was no change in drag by doing so. Finally, one tweak made a substantial difference (at least for me) — Roy angled my aerobars slightly downward. That very slight adjustment put my head position in a very efficient slot. That was the only adjustment ultimately made to my bike.
Testing Skin Suits and Helmets
We went on to test skin suits and helmets. I have used the Assos Chronosuit for the last couple of years because it had shown itself to be the fastest suit in the wind tunnel, and I have been utilizing the Kask K31 Crono Helmet for that same time frame. In the Speed Tunnel, I tried various helmets and found one that for me saved me about 20 grams of drag over the Crono. My significant other’s current helmet, a Louis Garneau, was faster than the other helmets she tried.
(On an interesting side note: It was discovered in the wind tunnel at Texas A&M that there is no such thing as a fastest aero helmet. It was shown through testing that results were quite individualized, and a helmet that might be the fastest for me might very well NOT be the fastest for you. Only the wind tunnel can tell you which helmet is fastest for you.)
With skin suits, the Hincapie suit had less drag than my Assos, and I suspect from what I am reading on the time trial forums in the UK, the Castelli Body Paint 2.0 might beat all of them.
Phenomenal Results!
My end results were phenomenal for someone already in quite an efficient position on the bike! By the end of the numerous runs in the wind tunnel, Roy tweaked me to the point that I had saved 111 grams of drag. At some extreme yaw angles, I saved up to 154 grams of drag.
These are big numbers that translate to a savings of about 1.1 to 1.54 seconds for each kilometer raced. It also translates to a savings of 11 to 15 watts, so I can attain the same speed when expending 11-15 watts less — thus allowing me to go faster when I expend the same effort as before.
To put the importance of this kind of savings in real life terms, I have been in a championship time trial race where the difference between first and second place was a mere 2/100 of a second! At the nationals some years ago, three of us were within 3/4 of a second. A second can be the difference from being on the top step of the podium or later telling your friends all the reasons you should have won but didn’t!
Rosie’s results were even more incredible — something that did not surprise me. She saved over 300 grams of drag from her previous position! That translates to 3 seconds savings for each kilometer and an amazing 30 watts of savings. She needed changes in seat height and fore-aft positioning, as well as her aerobar position. In addition, she needed shims added to the interior of her shoes.
At the end of the fitting process, the fitter does a substantial debriefing and supplies the person tested with a very informative Aerodynamic Analysis Report for each run, which graphically depicts the precise savings in drag for each change at the various yaw angles tested. Those angles range from 0 to 20 degrees in 5-degree increments.
Although wind tunnel testing has always been the gold standard for fitting on a bicycle, the cost is prohibitive for most of us. The Speed Tunnel Mobile Wind Tunnel changes all of that, making wind tunnel testing not only cost-effective, but it can come to you for your event, saving hundreds of dollars in travel expenses.
If you are serious about your racing, whether it be road or time trial racing, a wind tunnel fitting will give you that little extra advantage that could be the difference between winning and losing. Interestingly, the day prior to my and Rosie’s fitting, three riders from a British pro team were there with their coach being fitted in the wind tunnel on their road bikes. They were so pleased with the results, they intend to be fitted on their time trial bikes in the future.
— Sandy Scott
Leave a Reply