Archive for December, 2014

Every Conceivable Advantage – Aero Is Everything

Chris Yu - Specialized Explains Rim versus Disk Brakes in the Win Tunnel

Chris Yu – Specialized
Explains Rim versus Disk Brakes in the Win Tunnel

 

 

 

 

 

 

 

 

Every Conceivable Advantage

The Morgan Hill, CA based bike manufacturer Specialized has been running a series of wind tunnel testing articles and videos under the topic of “Aero is Everything.” See http://youtu.be/HXQuSnKkS-I

The latest “test” compares the aerodynamic advantage of disk versus rim brakes. Drum roll…rim brakes by… 8 seconds over a 40 time trial when a 10 degree “yaw” angle is introduced to simulate the effects of a cross wind.

This “compelling” marginal benefit follows a long distinguished list of imaginative questions about other potential aerodynamic advantages…shaved legs, no beards, ladies hairstyles, aero bars, helmets, ad infinitum…that Specialized is testing in their new own wind tunnel.

We just finished a field study with a prominent university’s Department of Sports Medicine on the performance and perceptual benefits of sustained cooling over the head and face during a 6 mile time trial.

What did we find as a “marginal benefit”?

The average time improvement for all riders [12] riding in temperatures from 84 to 95 degrees F was 10. 4 seconds. For riders performing in temperatures above 85 F [8 riders] the average time improvement using a cooling system was 15.9 seconds. Lastly three cyclists rode their TT at temperatures over 90 and their average time advantage being “cooled” during the ride was 46.6 seconds. Since the effects of heat stress is cumulative we might anticipate the time advantages would improve over the course of a 40 k TT.

The two opposing forces of accelerating or moving any body through space are thrust and drag or power and resistance. As the wind tunnel tests demonstrate there’s two ways to increase your speed:
Reduce drag ( wind resistance)
Increase power (thrust)

Numerous studies and a very common experience tells us that when its hot our ability to deliver and sustain power output falls.
You over heat your engine you start losing power.

While you looking for “every conceivable advantage” don’t forget “you’re the engine, never let it over heat.”

Improve and maintain your power with Spruzza, “A Cooler Way to Ride.”

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World Congress of Cycling Science – Cycling in the Heat

WCCS-2014           This YouTube Video on Cycling in the Heat is from the start to about minute 38. You can find specific mention of cooling the head and face from minutes 22-30. http://youtu.be/B2lubSFe1sc

Cycling in the extremes

SS Cheung1, C Lundby2

1 Environmental Ergonomics Laboratory,

Department of Kinesiology, Brock University, St

Catharines, Canada.

2 University of Zürich, Institute of Physiology.

Wednesday 2nd July

Lecture Theatre C: 15.30-16.30

Cycling is an outdoor sport that can be conducted in extreme altitudes and temperatures. Dr Cheung will outline that while hot weather clearly impairs performance, the underlying mechanisms may comprise both physiological and psychological factors, and their relative contributions remain contentious. Hyperthermia can lead to impairment across multiple physiological systems, from cardiovascular through to neuromuscular and neurohumoral.

Furthermore, a psychobiological paradigm of fatigue suggests that heat stress may alter a cyclist’s pre-planned performance template, along with their overall perception of exercise and voluntary exercise capacity. Progressive adaptation to heat can improve performance in hot weather, but the transfer of these adaptations to cycling in more temperate environments is unclear. A number of additional countermeasures to combat acute heat stress and delay the onset of hyperthermia-induced performance impairment will be surveyed.

Dr Lundby will outline that the general practice of altitude training is widely accepted as a means to enhance sport performance despite a lack of rigorous scientific studies. For example, the scientific gold-standard design of a double-blind, placebo-controlled, cross-over trial has never been conducted on altitude training.

Given that few studies have utilized appropriate controls, there should be more skepticism concerning the effects of altitude training methodologies. In this talk he will aim to point out weaknesses in theories and methodologies of the various altitude training paradigms and to highlight the few well-designed studies to give athletes, coaches and sports medicine professionals the current scientific state of knowledge on common forms of altitude training. He will furthermore highlight acclimatization strategies that play a key role in optimal performance at low to moderate altitudes.

 

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