Thanks for clarifying. Given the considerable amount of motorcycles that are way too loud, it still feels like the noise limits for homologation are way too high. Or if that many bikes have been tampered with, it means there really is absolutely no enforcement whatsoever. Either way it sucks :/
I would have thought French have a more strict approach given how they throttle performance of bikes. Like a hayabusha with 100 HP. I think a while back max. performance was 100HP for bikes.
Well, as always, there's the theory, and then there's the practice.
The 100 HP law has been removed around 2016 because the EU said it was it against free trade in the block. I'm not really sure how that works and if a vehicle must only comply with EU regulations in order to be sold in any and every country. As a biker, I'm happy it was removed. It was just silly and useless. A 100 HP bike, even a heavy one like a Hayabusa is powerful enough to give you a bad day if you have no idea what you're doing [0].
More related to the issue at hand, limiting was very easy to circumvent and practically impossible to verify without putting the bike on a dyno. Older, non fuel injected models only had some kind of mechanical limiting for admission. My bike was limited by the ECU which is trivial to swap. Actually in my particular case it's a bit more involved since the coded key is tied to the ECU, so you'd have to also change the key. The ECU is just a black box with a bunch of connectors. It doesn't say anything as to what it does.
It's more or less the same issue with mufflers. They're pretty trivial to change and even if they're sold as street legal, it's very easy to remove a capsule to "open" it up.
However, this is much easier to control than the ECU mapping. Just put out a mic and measure the sound level. Is it above the value in the registration? It's illegal. Done.
But I think it's just much easier to enforce speed limits. Just set up a speed camera and take pictures of the guys passing by. You don't even have to stop them. And, as a bonus, it counts as "doing something" for traffic safety.
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[0] One good thing in France (and maybe the whole EU, now) is that getting a motorcycle license is not as easy as the car license. But in traffic stats, motorcycles are usually counted in the category of "2 wheelers" (which actually includes some trikes). The issue here is that not everyone has an actual motorcycle license. And, related to the power issue, it would seem that "inappropriate speed" was a factor in more accidents involving small bikes (those not requiring the full motorcycle license) than bigger ones. Below is a (2008) study showing that:
* "small bikers" are more often the cause of the accident than "big" ones.
* big bikes, when the cause of the accident was a "loss of control", were on average going 15 km/h above the posted speed limit. Pretty much any 100 HP motorcycle can go above 145 km/h (highway speed limit is 130).
