So, the short story is that some people claim that Cancellara is cheating by putting a hidden electric motor in his bike. Now they are going to do random hidden-motor checks.
I have analyzed this motor-in-a-bike already:
- Energy in a hidden battery: The short answer is that you could get about 500 watts for about 1.5 hours with a hidden battery that weighs 1.6 kg. Doable, yes. Advisable? Probably not. Also, you would probably hear the motor being used.
- Do bikers cheat? In this post I look at some clips of Cancellara in cases where he could be using a hidden battery. Conclusion: he is not doing anything extra-human that would make it mean he could only do it with a hidden motor.
I propose the following: Let's make up some other rumor such as Cancellara is really a half-elf and see if they start doing random testing for half-elfness.
But half-elves have immunity against sleep, as well as low light vision. These are clearly unfair advantages.
The difference is that electric motors and batteries exist, unlike elves. Testing for different possible ways of enhancing a bike makes perfect sense, if for no other reason than to ensure that no one is tempted to cheat.
And if you cheat you had better make it in a way that isn't too obvious so your claim that you can't see cheating proves nothing. Just adding a few watts of electric energy during an entire race may give you that extra edge to end up first. Unless there is testing to make it impossible, at some point someone is bound to try, there is just too much prestige and money involved.
If I used that kind of tricks, I would build the system with a regenerator that recharges the battery from braking energy. The batteries could be smaller, and you could still get your 500 watt boosts for hours at best.
They also added strict limits on when you could swap bikes.
Since the top athletes can "only" produce about 500 W in sustained effort (measured by really cool wheels), you don't need to go that far to gain a huge advantage. And could you really hear it over the noise of several hundred chains on gears turning at 30 mph, more in a sprint, plus a crowd and motorcycles and cars?
But you can find the drive system pretty easily if you take apart the crank during an inspection, so taking that risk is in the same category as doping these days.
PS - If you can find an overhead shot of one of those sprints where Cavendish blew the wheels off the competition, I'd love to know what their speeds and accelerations looked like. The last one, where he and Petacchi started sprinting at the same time, might be really interesting.
There is an example of an overhead shot in this highlight video from the Tour (at about the 2:40 mark)
but it would seem really difficult to pick out a clear scale. For example, I can't make out any of the 100 m markers.