Sarah Hammer Wind Tunnel Testing Her TK1
Sarah Hammer – the world’s most decorated track athlete – is now testing the Felt TK1 in her Wind Tunnel debut, but got her clavicle broken in the women’s points race final.
What is Felt?
To start off, Felt is a well-established bicycle company founded by Jim Felt in 1991; however, not until 2001 did the company actually make a relaunch. There is a lot to discuss when it comes to technologies that the company incorporates into its wide variety of bicycle products.
Lines of product
First, the full-suspension mountain bikes feature the Equilink suspension system, which maintains the efficiency of the bike’s pedaling regardless of any rough terrain. Moreover, triathlon bikes come with Bayonet Fork technology, which makes use of an external steerer to improve aerodynamic efficiency and stiffness.
With the Wind Tunnel testings, Felt has successfully created a bike that is just as efficient and robust as other competitor’s, yet requires less effort to achieve and retain the desired speed. That’s a huge advantage for any cyclist.
Aerodynamics
Speaking of aerodynamics, Felt’s aero bikes are developed in the wind tunnel in which the prototypes are tested and refined to perfection. After that, they are sent to professional and experienced bike testers such as the Olympian Sarah Hammer and the Olympic time trial gold medalist Kristin Armstrong.
The TK1 is the ultimate track bike used by Sarah Hammer in her quest for gold medal. It is best suited for endurance disciplines, sprint and hardcore riders. Since the TK1 is tested by the multi-time World Champion Sarah Hammer as well as other experienced Olympic riders, it is by far one of the best bikes for track athletes.
Features and their technology
In terms of construction, TK1 features a Felt UHC Advanced carbon fiber frame, Rotor 3D25 crankset and 3T SCATTO LTD bar, all of which turn this bike into a monster.
| Features | Technology |
| Frame | Felt Aero Track UHC Advanced carbon with titanium surfaces, integrated chain tensioners |
| Drivetrain | 1-Speed KMC X101 Chain |
| Fork | Felt Aero Track UHC Ultimate carbon fiber |
| Headset | Integrated with FSA IS, Felt top cap, aluminum bolt |
| Stem | 3T Team Stem, titanium bolts |
| Handlebar | 3T SCATOO LTD carbon fiber |
| Grips | Felt VelvetGel Tape |
| Bar Ends | Felt Bubble-Tech F Wing |
| Crankset | Rotor 3D24 TRACK |
| Chainwheel | Rotor 49T |
| Bottom Bracket | Rotor |
| Chain | KMC X101 1-Speed |
| Freewheel | 15T with lockring |
| Saddle | Prologo Zero II CPC TiRox |
| Seat Post | Felt TK1 carbon fiber
3T DiffLock internals |
| Seat Post Clamp | Felt Aero Integrated TK1 |
| Rims | Felt TKR1 (Reynolds tubular) |
| Front Hub | Felt TKR1 with sealed cartridge bearing (28H) |
| Rear Hub | Felt TKR1, with sealed cartridge bearing (28H), double-threaded |
| Spokes | Double butted stainless steel |
| Tires | Challenge Pista Ultra, I 1000 + TPI Silk casing |
The technology used is what makes TK1 far exceed the standards of regular track bikes, and has been a solid company with the multi-time World Champion Sarah Hammer as well as other Olympic cyclists. In other words, TK1 is the definition of a world-class track bicycle. The fact that it weighs only 15lbs (or 7kg) greatly contributes to the swiftness and flexibility of the rider, and Sarah Hammer made the most out of it on her conquest of medals.
In fact, the TK1 bears a resemblance to the Felt DA triathlon bicycle that was used by Kristin Armstrong to win the Olympic time trial. On close inspection, it is also built with Felt’s Bayonet fork, front and rear wheel wells and horizontal drop-outs.
More information about Wind Tunnel Testing
Let’s talk about the Wind Tunnel. Based in San Diego, it has become the must-to-go testing place for cyclists to keep track of their performance. Surprisingly, wind tunnel testing has been around for more than 10 decades, and it has become essential for modern-day racing nowadays.
For that reason, the expense for this testing starts at least from 5 figures, and will probably go up in the future. A great number of athletes or Olympic teams spend time doing detailed aerodynamic training in order to bypass their competitors.
The fact that there are so many in the same field makes this testing a necessity if they want to be competitive and bypass other cyclists. Jim Felt once said:
“In this day and age, with all the riders on the same playing field, I absolutely believe it’s a necessity to be competitive.”
Although expensive, the wind tunnel testing is well worth the money, time and effort if cyclists know how to make the most of it.
Jeff Soucek Discusses Testing The TK1
History of TK1
Jeff Soucek, director of engineering at FELT, expressed his pride in the TK1, which is one of the most advanced track bikes ever produced. Its versatility and high functionality distinguishes it from other bikes, making it not only a notable sprint bike, but points bike and pursuit bike as well.
With hindsight, in 2012, four American female athletes (Sarah Hammer, Dotsie Bausch, Lauren Tamayo and Jennie Reed) had their name recorded in history. On their conquests of silver medals in the women’s team pursuit, all of them all used FELT BICYCLES TK track bikes.
The directory of engineering, Soucek, once noted:
“The only way to make something the absolute best it can be is to be really focused on it.”
Surely, track bikes in general are designed purely for use on a velodrome, and there are 3 different types of bike tracks: sprint events, pursuit events, and endurance events. The FELT design and engineering team has made the most of it, making it by far one of the best bikes for track athletes.
Though there are three styles, they all share basic components: frame and fork, handlebars, wheels, cranks, pedals, chainring on the front, a cog attached to the rear wheel hub and the chain.
New idea – is it better than the previous TK1?
Shortly after the bold victory of the four female athletes, the U.S. Cycling Team was challenged by racing fans if they could gain victory in the Olympic Rios in 2016. For that reason, FELT constructed a newly-designed TA FRD, or Track Aero | Felt Racing Development with the hope to win a gold medal and most importantly, overtake team GB.
The new FELT TA FRD is built based on the absolute best track bicycle TK1, but what distinguishes it from the 10-year-old TK1 is that it is designed solely for the pursuit discipline. This one also undertakes drastic developments with the help of computational fluid dynamics modelling as well as the wind tunnel testing.
In order to create a pure track bike for athletes of the pursuit squad, engineers at FELT BICYCLES have decided that research concerning airfoils be carried out inside a velodrome for future implications.
What is a velodrome?
In simple explanation, a velodrome is a stadium or arena for tracking cycling, featuring a cycle-training track with steeply banked curves that comprise two 180-degree circular bends connected by two straights. After the research, they have come up with revolutionary asymmetric cross sections as well as the left-hand position of the crank.
Once there exists asymmetric airflow, cyclists can optimise shapes for that flow, which ultimately leads to a faster bike. Anton Petrov has also confirmed that the TA FRD is designed specifically for the velodrome.
Testing results
From the tests, they’ve realized that airflow from the drive side tremendously increases the aerodynamics of the bike and in turn, helps it handle better as the weight and center of gravity situated inboard of the turns.
One of the most notable improvements is the positioning of the drivetrain, which has been now placed on the left-hand side. As of the result of the research, moving the drivetrain from the outside to the inside of the track makes the bike much more aerodynamic.
Jeff Soucek, the directory of engineering, strongly believed that aside from those huge developments, there are various small features that have been incorporated to make the bike unique and fast.
Developments and improvements from TK1
The production of this new design requires some willing equipment partners, including a custom Metro TT crankset, a carbon dual fibre dual sensor power meter, custom wheelset with narrow hubs (70mm at the front and 95mm at the back), a narrower fork and rear stays, and a refined tube.
FELT BICYCLES also adopted new tapered dropouts to prevent the wheel from sliding forward by doing away with the usual set screw that positions the rear axle, and it also made use of the TeExtreme carbon fibre frame that has been used by many high-end road bikes.
Differences Between Track Bikes and Other Bikes
| Track Bikes | Road Bikes | Mountain Bikes | Fat Bikes |
| ● Stiff frame
● Narrow tires ● Single gear with no freewheel ● No brakes ● Specifically for velodrome racing |
● Lightweight
● Drop handlebar ● Narrow tires ● For recreational purpose, on paved paths |
● Relatively heavy
● Flat handlebar ● Wide, knobby tires ● For rides on narrow, dirt trails |
● Wide tires (at least 3.8”)
● For flotation and traction (on snow, sand, trail) |
What makes track bikes different from road bikes?
In terms of geometry, track bikes have shorter reach, slightly shallow fork rake and shorter top tube in order to maximize speed handling. The bottom bracket is placed higher to provide cyclists more pedal clearance, especially when it comes to banked corners.
Track bikes are also more aerodynamic and robust so as to optimize acceleration and power transfer. The fact that track bikes are equipped with single speed gear ensures higher cadence efficiency, which makes it even more suitable for races that entail repeated accelerations.
In short, track bikes feature single gear and no brakes. The true purpose of these bikes is for races on a velodrome.
Types of track bikes
- Standard
Similar to conventional road bikes as they also have drop handlebars, standard track bikes are made for mass-start races like points races.
- Sprint
Relatively heavier and sturdier, and the riding position is more aggressive compared to the standard ones so that they are able to resist the forces of maximum sprinting placed upon.
- Pursuit
Pursuit track bikes are specifically designed for timed or trail events. These bikes greatly stress aerodynamic tube shapes and wheels, and they feature flat, horn-style handlebars.