Tuesday, June 10, 2014

Championship TT Build

by Jack Mott


Being former or current multi-sport athletes in many cases, the ATC Racing women pride themselves on their time trialing prowess and put up impressive results at this year's state TT. Katie Kantzes nailed a third place in the Eddy Merckx category, Marla Briley got second in category 3, and Kat Hunter took first place in Cat 1/2. Read Kat's race report on TexasBikeRacing.com.

On Sunday, the team of Missy Ruthven (ATC owner), Maggi Finley, Marla Briley, and Kat Hunter backed up those impressive results with a 56:37, fastest women's time, in the team time trial.

To give you an idea of the attention to detail that goes into a winning time trial, we will break down all the gear, aero data, and power data of Kat Hunter's winning ride.



Bike Build Specs


Power Meter Data
  • Goal Power -  250 watts
  • Actual Average Power - 247 watts
  • Variability Index - 1.0
  • First Half Power (Headwind) - 254 watts
  • Second Half Power (Tailwind) - 241watts
  • Avg Temp - 82 deg G
  • Avg Cadence - 92
  • Avg Speed - 26.6 mph
  • Distance - 40k
  • Time - 56:23

Power File


WKO+ Power File from the TT

Aero Data

Approximate yaw angle distribution from BestBikeSplit.com


Using BestBikeSplit, an excellent online aerodynamic and pacing tool, we can approximate that Kat had a CdA of approximately .20 at 0 yaw, and .19 at yaw. We can also see that about 70% of the race was between 0 and 5 degrees of yaw, with most of the rest of the race between 10 and 15 degrees of yaw.  Knowing what the angle of attack of the wind is during a race can help you make intelligent equipment choices. For instance, we can see from this data that a deeper front wheel would have been faster, as around 30% of the race had yaw angles where a Jet 9 is a bit faster than a Jet 6.  Over 70% of the race was at very low yaw angles, which means choosing a narrower tire was definitely a good call.

Close-up Bike Shots 

The venerable P2 Classic remains competitive

View Speed Skewers, Cervelo FK26 fork, and HED Jet 6 with Continental Attacks

HED Jet 9 with a disc cover taped on,  nice clean chain

TriRig brake, stem, and HED aerobars make for a clean front end





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