Thursday, January 27, 2011

Cadence Case Study: Scott Zwizanksi

Part II: Individual Fit Priorities

Part II in a series of blogs that focus on Scott Zwizanski and his work with Cadence Cycling & Multisport in advance of the 2011 season. For Part I, scroll down.
In our last blog we introduced our work with Scott Zwizanksi, Cadence-coached athlete and time trial specialist, as he prepared for 2011 with his new United HealthCare team. Scott’s new team had him in the A2 Wind Tunnel in North Carolina to hone his aerodynamics, but not before Brady Gibney and Colin Sandberg had a chance to work with him on his position. This week’s blog will focus on just that; individual fit priorities that every athlete has, that allow them to maximize their return come race day.

Let’s start by looking at Scott’s individual fit priorities from a 10,000 foot view, and then break each down and explain how our coaches addressed each one before he stepped foot into the wind tunnel.

Maximize Biomechanical Efficiency
From Scott’s years of being coached by Brian Walton and corroborated by the recent tests we’ve done, we know that Scott as a rider is most powerful at higher RPMs with open hip-angles. With a strong core built from years as a collegiate swimmer, we know that Scott can tolerate positions forward over the bottom bracket. This allows Scott to operate at higher RPMs while also rotating him forward, which could potentially lower his frontal area resulting in better aerodynamics.
Result: Saddle height increased .7cm
            Saddle setback decreased to -5.0cm

UCI Bike Regulations
Unfortunately, bicycle fitting is not limited to only the rider’s capacity but also by Union Cycliste Internationale laws. These laws dictate that a rider and his machine must fall within a certain set of dimensions, or they will be unable to compete in UCI (read, most every professional race) competition. For a breakdown of UCI time trial regulations, see the following article from our friends at Slowtwitch:

This presented a slight issue in Scott’s fit because of his efficiency at higher RPMs mentioned above.  UCI regulations limit the distance behind the bottom bracket that a rider can be to -5cm, and that is as far as we could move Scott forward.
Result: Saddle setback limited to -5.0cm behind bottom bracket

Similar to the concept of economy testing, a riders’ ability to adapt to new positions comfortably is a serious consideration even for a professional cyclist. Often times, amateur cyclists will try to emulate professional cyclists’ positions with long reaches and deep drops. Professional cyclists ride an average of 60,000km a year and have thousands of hours adapting and honing their position without sacrificing power or speed. You wouldn’t get into a 1,000 horsepower Formula 1 car days after learning how to use the clutch in your Honda Civic.

Scott’s had not been spending a lot of time on his time trial bike in the off-season, and had mainly been riding his road and mountain bikes in preparation for the 2011 season. Given our short time frame, assumptions had to be made that in time his body would settle into his new position comfortably. We are lucky to have years of experience coaching Scott and were able to use his expert feedback about the small changes we made to his position.
Result: Drop from saddle to handlebars decreased 3cm

Maximize Economy in the time trial position
As mentioned last week, the term “economy” is a hot button in physiological testing as of late. With economy, we are not just looking at how much oxygen your lungs can intake (maximal oxygen uptake) but how oxygen usage is affected in different positions on the bike. Measuring economy is not only your body’s capacity, but its functional capacity on the bike in different positions.

Our priority with Scott was a bit more complex because we knew his position would change once in the wind tunnel, so our goal was to find the range of high-economy positions that he could hold during time trials. Once the above changes were made to Scott’s position, testing was required to determine if we have found an acceptable range to take to the wind tunnel. Testing was completed over two days on Cadence’s ParvoMedics measurement module to measuring Scott’s heart rate, lactate concentration, VO2, and respiratory exchange. On the first day we tested Scott’s original position followed by a 20-minute rest and then tested again in the new position. On the second day we tested Scott’s new position first followed by a 20-minute rest and then tested again in the old position.

Day 1-Original Position
Day 1- New Position
Day 2- New Position
Day 2- Original Position

The Results
 A final report sent from Cadence coaches to Scott’s new team director read as follows, “There was no significant, consistent, and sizeable differences to the physiological responses between the original position and the modified position, therefore it is likely that the subject would be likely to adapt to a more aerodynamic position without significant physiological cost.”

If you reference the above graph’s bottom line, you can see for yourself there were minimal differences to Scott’s physiological responses to the two positions. By taking into consideration Scott’s individual fit priorities and testing accordingly, Brady and Colin knew they were sending Scott to the wind tunnel in North Carolina with the best possible position to work from. Please check back soon as we delve into the final blog of our series, Part III: Into the Wind Tunnel

Thursday, January 20, 2011


Your Grandmother's Cookware Will Make You Faster.
Bicycle mechanics are skeptics. It is a fact of life. Our job forces us to question designs put forth by manufacturers in order to make reasonable recommendations to our customers. New technology is something we approach with intense scrutiny, often taking more time than some would say is reasonable to give our stamp of approval. We are conditioned to do so. Bicycle and component manufacturers are constantly reinventing the wheel—literally. New designs, regardless of whether they are practical—or even beneficial in any way, are a great way to recapture a market. Fads are more common in bicycle culture than popular music, which, being a musician, is something I surely thought was entirely impossible. Failed designs abound from the annals of cycling history like nor’easters in Philadelphia—at least lately. Take Mavic’s now prophetic, but ill conceived electronic shifting system ZAP, or Campagnolo’s convoluted Delta brake design—or even Shimano’s BioPace. All designs that had engineering merit—especially considering the recent success of Di2 and Rotor Q-rings—but failed to catch on.

After all this, you can’t blame me for being slightly hesitant when ceramic bearing technology started to crop up in bicycles. If I am being absolutely honest, I thought that ceramic bearings were a total hoax until recently. Before we get into that, though, I think a crash course in bearing basics is in high order.

There is a plethora of articles that discuss all angles of bearing technology as it pertains to cycling all over the internet. So I will do my best to stick to the basics. These two articles from Zipp do a great job of explaining some of the merits of “good bearing design” so I will save my breath by not delving into radial contact vs. angular contact. Bearings are classified in two different ways: Grade, and ABEC rating. ABEC or Annular Bearing Engineering Committee ratings are used to classify the roundness of a ball bearing. A high ABEC rating means that the bearing has a lower eccentricity than a lower ABEC rating. These ratings are ideal for applications that require a smooth rolling bearing at extremely high RPMs. I’m talking like 30,000 RPMs. So unless you do your fast cadence drills at 30,000 RPMs, any rating of ABEC 5 or higher (9 is the highest) will do just fine. Cyclists often put too much emphasis on an ABEC rating. The real rating that effects cyclists is a bearing’s grade. Grade measures three things: surface integrity, size, and sphericity. What you need to know: the lower grade is better. A grade 2 or 3 bearing is ideal. A bearing’s manufacturing tolerances, however, are not the only cause of drag. Bearing seals and lubrication viscosity are major players in causing bearing drag.

So why does all this matter? How does ceramic technology come into play? Relax, I am about to tell you.

Si3N4 (Silicone Nitride) Ceramic bearings are not only lighter than standard steel bearings, but they are also stronger. Zipp claims a 30% weight savings and a 40% gain in overall strength. I haven’t seen the studies to confirm this, but Zipp is a technology driven company. They have loads of engineers doing complicated math problems with lots of numbers and decimals that I trust know more than I do about these kinds of things. I think it is safe to say though, that ceramic is a stronger lighter bearing material than steel. The savings in weight is negligible at best, but the gains in strength have major ramifications when it comes to rolling resistance. A stronger ball means that you can use a thinner (more viscous) lubrication and seals that cause less drag. This directly translates into a faster rolling bearing. Though the reduction in drag is mostly caused by low drag seals and high viscosity lubrication, these are only options because the ceramic ball is less susceptible to wear. If you were to use the same seals and lube with a steel ball, the life of the bearing would be drastically reduced—maybe even destroyed in a single ride.

Both steel and ceramic bearings can be manufactured to the same grade and rating, but that does not mean that they will perform the same over time. Besides the performance gains I already mentioned, a ceramic bearing will hold its grade longer. As a steel bearing wears, it will come out of round and small chips and imperfections will form on the surface on the bearing—both causing rolling resistance. Ceramic bearings are much harder than steel, meaning they will hold their form and resist chips and cracks for much longer than steel.

Like steel bearings, however, ceramic bearings are not all created equal. Actually, grade 25 bearings or higher don’t even have the right to vote in most states. When making a choice of bearings make sure you pay specific attention to grade, type of seal, and both viscosity and fill rate of the grease.

I know you are all asking, (silently in your head, I hope—because otherwise you would be talking to a computer…and everyone would be whispering about you) “All this technical jargon is well and good, but what good does all this do me out on the road? How much difference does it actually make?” I asked myself similar questions—it being a part of my inquisitive nature. Where’s the beef, so to speak? Well, the beef is in the pudding…or something like that. All the technical information and scientific studies in the world wouldn’t mean a thing unless it makes us enjoy riding our bikes more, right? That is why we love cycling—for the riding.

Here in the shop we recently had an opportunity to install ceramic hub bearings and derailleur pulleys on Thomas Brown’s Cyfac. Thomas is one of our favorite customers, so when he asked us to hook his bike up with some ceramic upgrades in addition to a full overhaul, we were really excited to dive into the project.

Believe it or not, derailleur pulleys are one of the leading causes of drag among drivetrains. A faster rolling set of derailleur pulleys will improve shifting, as well as greatly reduce drivetrain resistance. We replaced Tom’s old Campy pulleys (which are better than most standard pulleys to begin with), with Enduro Zero pulleys.

Shiney Enduro Zero Pulleys-The derailleur before the overhaul

---Disassembled----------Cleaned and ready to go!-

With the installation of the pulleys the drivetrain spun with very little resistance. With a spin of the pedal, the crank would rotate at least 3 full rotations. (spin your crank arms on your bike….they probably don’t go around 3 times). Before the conversion, Tom’s cranks spun about 361.7 degrees around. I measured it.

We also replaced old campy steel bearings and retainers with shiny black Si3N4 ceramic bearings with a synthetic retainer.

-Campy Ceramic Bearings---The hub before the conversion--

Notice that Campy recommends using only a light oil to lubricate the bearings.

-New bearings and oil-----------The finished product.----------

This allows for a drastic reduction in rolling resistance. I was thoroughly impressed when I took this bike out for a test ride. The Cyfac Nerv is a great riding bike to begin with, but I was totally struck at how smooth the bike rode after the conversion. It spun up smoothly and was very responsive. I immediately looked into ordering ceramics for my Caad9, but then I remembered that I’m completely broke. Oh well.

So what can we take from all of this?

Ceramic technology really does make a difference out on the road, but are a more expensive than standard steel bearings. So you have to ask yourself how much you are willing to spend for the top level of performance. We all have to decide between bike upgrades or say…donuts. For me the choice is obvious: donuts.

Thanks for reading. See you at the shop.


PS. I would love to hear any comments or suggestions for topics for the mechanical posts on this blog. This blog is yours just as much as it is mine—except for the fact that I write the posts. But I really do want to know what topics you are interested in discussing. Don’t hesitate to email me at Or leave your comments and suggestions in the “comments” section. Rocket science, right?

Additional Links and Pictures:

Ceramic Tech Information
Zipp Si3N4 Technology
F1 Ceramics explains grade and ABEC ratings
Mavic ZAP
Campagnolo Delta Brakes
Shimano Biopace

Thursday, January 13, 2011

Scott Zwizanski at the Wind Tunnel

Cadence Case Study: Scott Zwizanksi

Part I: More Than Meets the Eye

Cadence athlete Scott Zwizanksi works with Cadence Cycling & Multisport Coaches to determine potential of his time-trial position in advance of trip to wind tunnel.

Time trial specialist and Cadence-coached athlete Scott Zwizanksi is busy preparing for the 2011 season with his new team, United HealthCare. When Scott’s new team joined forces with legendary time trial specialist Chris Boardman and the Boardman line of bikes, an opportunity arose to get Scott into the wind tunnel to squeeze the most out of his position. With full support from United HealthCare team staff, Scott’s long-time coach Brian Walton identified an opportunity to maximize his athlete’s position before he even stepped a foot into the wind tunnel. By combining the Cadence coaching staff’s knowledge of biomechanical fitting and physiological testing with United HealthCare’s resources, the question remained; how much faster could we make Scott Zwizanski?

Before Scott attended a two-day wind tunnel testing session at the A2 Wind Tunnel in North Carolina, he worked extensively with Cadence coaches Colin Sandberg and Brady Gibney to collect data and hone his position. The goal; optimize Scott’s time trial position for biomechanics and physiological efficiency so that United HealthCare and A2 wind tunnel staff understand the effective ranges in which Scott’s body can tolerate improvements to aerodynamics. Even in the ranks of professional cycling and triathlon, there must be a marriage between the most effective aerodynamic position and the most effective biomechanical position. Put simply, Scott needed to know just how much his body could be modified on the time-trial bike for the sake of aerodynamics without sacrificing sizeable amounts of power. It is a balancing act between low drag, max wattage and going fast. If Scott could go into the A2 wind tunnel in a powerful and economical position, he would maximize his resources and leave with the fastest position possible.

There is more than meets the eye when it comes to bike fitting, so not every position that looks good is efficient and powerful. Every athlete has a unique set of physiological capacities that demand the fitter to adapt the bike to the rider, not vice versa. With this in mind, Colin and Brady began a two-day fit examination that would analyze Scott’s old position and determine how his body would adapt to new positions. After making adjustments to his “old” fit,  data was collected by having Scott perform VO2Max and Economy tests with each corresponding position. With an Economy test, we were not just measuring maximal oxygen uptake – we were studying to see how oxygen utilization is effected by different positions at different power outputs. Measuring Scott’s economy allowed us to see specific oxygen usage for different positions, painting a better picture of just how precisely his body could adapt to different positions in the wind tunnel.

Here was the caveat, though; the UCI, the governing body of cycling, limits the degree of changes a rider can make to his position. So Colin and Brady had to analyze Scott’s position, maximize it for power and efficiency, and prep it for aerodynamic modifications in the wind tunnel…all while keeping within UCI dimensional regulations for a time trial bicycle. We knew that Scott generates power from tremendous leg speed as opposed to mashing low gears, so getting him over the bottom bracket for an open hip angle without violating UCI regulations was a significant issue.

We will be using Scott Zwizanksi’s case study as a means to educate readers on the effectiveness of an individualized bike fit done by professionals. Our hope is that by giving an inside look at our work with Scott, readers will understand the intricacies of a bicycle fit and just how exactly our coaches work with each athlete for the best possible result. 

We will begin in our next blog with a more thorough explanation of how Colin Sandberg and Brady Gibney were able to maximize Scott’s fit by taking into consideration the variables of new equipment, UCI regulations, and Scott’s physiological capabilities to adapt to new positions. Please look for Part II: Individual Fit Priorities next week.