First Time Trial Prep: 48-Hour Guide
“`html
The Pursuit of Marginal Gains: A Last-Minute Time Trial Experiment
Table of Contents
Sometimes, a challenge presents itself with little planning.Recently, I found myself signed up for a 20km time trial with just 48 hours to prepare. Knowing a notable training block wasn’t feasible, the focus shifted to optimization - squeezing every possible watt out of my existing equipment.
The Course and the Rules
The race took place on a relatively flat, 16km (10 mile) out-and-back course with a total elevation gain of 90m (295 feet). The final 2km featured a slight 3.7% gradient. Crucially, this was a ”Merckx-style” time trial, meaning road bikes only – no aero helmets or wheels deeper than 60mm.
With limited time, the strategy became clear: leverage the adjustability of my Canyon Aeroad to dial in the most aerodynamic setup possible.This bike’s ability to modify bar height, width, and style was key.
Component Breakdown: A Deep Dive
Handlebars
the question was how narrow to go. I compared the stock Canyon ‘Classic’ handlebar (narrowable to 37cm) against an ‘aero’ bar that could narrow to 35cm. The potential gains were uncertain, but worth investigating.
Wheels
Three wheelsets were in contention: Zipp 454 NSW (1,430g, 58mm deep), Magene exar Ultra DB508 (1,375g, 50/58mm deep), and Fulcrum Speed 57 (1,470g, 57mm deep).The Zipps were well-used, the Magene wheels were newer and stiffer, and the Fulcrums offered a balance of performance characteristics.
Tires
The final piece of the puzzle was tire choice. I tested Pirelli P Zero Race RS TLR 28mm, Specialized RapidAir TLR 28mm, and Vittoria Corsa Pro 28mm, all of which had seen some miles but were in good condition.
The Testing Methodology
With limited time, a wind tunnel wasn’t an option. Instead, I employed the Chung Method (Virtual Elevation method) using a 1km loop ridden without braking. This involved collecting data on speed, power, and environmental conditions (using wunderground.com) and applying rolling resistance data (from Bicycle Rolling Resistance) to estimate CdA (coefficient of aerodynamic drag).
The Results: Surprising Insights
The data revealed some unexpected findings. While narrower handlebars are often considered more aerodynamic, the aero bars actually resulted in a 4-watt *increase* in drag compared to the standard bars.This suggests that individual fit and comfort play a significant role.
The Magene Exar Ultra DB508 wheels emerged as the fastest option, saving approximately 20 seconds over the 20km course compared to the other wheelsets. However, their stiffness and susceptibility to crosswinds were noted drawbacks.