Skinsuits in Downhill Mountain Biking

This topic is about a year old now, but I wanted to write about it anyway, because it is the best example I can think of where a governing body has inconsistent rulings on various technologies... in my opinion because they don't have a proper definition of the purpose of their sport.
In this case, the sport is downhill mountain biking and the governing body is the UCI (International Cycling Union). A little bit of background on the issue of skinsuits in DH is probably appropriate.
For years downhillers have been wearing skinsuits at world champs (where they were often required to by their national teams), but usually not at other races. See below if you don't know what a skinsuit is; the first rider is wearing "normal" (moto-style) clothing, the second a skinsuit. Indidentally they are both Tracey Moseley. Images from www.kona.com and BritishCycling.org.uk.

To explain their decision not to wear skinsuits at non-championship events, riders tended to say things like that they knew skinsuits provided an aerodynamic advantage, but were not prepared to risk their personal image or pissing off their sponsors. At the 2008 world cup finale in Canberra, there was a bit of controversy when Tracey Moseley wore a skinsuit in her final run, and won by 4 seconds over second place getter (and baggy clothing wearer) Rachel Atherton. Rachel responded by writing the words "skinsuits suck" on her forearms on the podium:

(photo and captions from Rotorburn forum)

Rachel was widely quoted (e.g.) saying: "Fair enough to Tracy if she wants to do that to win, but for the sport and the longevity of the sport, to wear cool race kit and to make an image for yourself is more important than the odd win here and there"

A few weeks after this, the UCI released a rule change, stating that "All lycra-elastaine based tight-fitting clothing is not permitted" in downhill mountain biking. [UCI Regulation 4.3.013]

The change in rules was not necessarily the result of Rachel Atherton's whinge alone, but the timing of the rule change certainly ensured that many people linked the two occurences.

I was unable to find any official document stating the UCI's reasoning behind the decision, which would be interesting to know, since in my mind it is completely illogical.

There are really two separate issues that I can see:

1. If image (whether of the individual athlete or the sport as a whole) is more important than performance.
2. If performance enhancing technologies are unfair.

The first point is clearly a matter of opinion, and although one that I personally disagree with, I won't get into that here.

The second point has some legitimacy to it, and people might draw parallels to the current swimsuit saga, but with reference to the sport of downhill mountain biking it is incredibly inconsistent and illogical. There are many other performance enhancing technologies that are exploited in DH, without regulations blocking them. There are very few UCI rules regarding the bikes themselves for example (despite strict UCI rules for road and track bikes). Different tyres, suspension systems, etc all play a significant role. If the UCI's intention is to reduce/ eliminate technological differences between athletes, then they should make that known, and form a consistent set of rules that cover every technological aspect of the sport.

As is the case with many of the UCI's rules (examples of which I am sure I will return to in future posts), the intention of the rule is unclear, and the wording vague, making its enforcement problematic.

Tracey Moseley points out: "I think that it (the rule) is even more unfair than someone being able to wear a skinsuit. Before it was a case of wearing one or not. If you were stupid enough to not wear one that was your own choice. Now we are in the dangerous position of having to ask how tight is too tight?" [from an interview on the British Cycling website]

Finally, I want to point out that the contribution skinsuits make to time savings is probably not as great as many people believe to be the case. In the afformentioned Moseley v. Atherton competition, Moseley won by 4 seconds on a 3:10 course (~2%).  She also had the fastest qualifying time which she achieved without "tight-fitting clothing." It is important to remember that DH is not all about aerodynamics, to the extent that a sport like skeleton or even skiing is. There is a lot of braking done in DH mountain bike, and so simple calculations involving average speeds and drag coefficients significantly overestimate the effect of drag reductions. One day in the near future I am planning on doing some detailed comparisons that include braking, so watch this space!