Motorcycles are dangerous.

We do.

We say many things that do not stand up to logic. It's just something you have to live with. You don't have to say these things yourself, but others are going to.

Thanks, roger.

I had a motorcycle accident at age 22 that nearly killed me. A motorcycle itself might be dangerous [to ride] if e.g. the brakes or steering don't work properly, or the tyres are deflated or worn, or the petrol tank leaks. Furthermore even if the machine is sound, there are the hazards of the road. A monotrack vehicle is more at risk from bad road surfaces, ice, oil, etc. Also there are other drivers (as Tanguatlay says). Any accident at all is more hazardous because the rider is vulnerable. I think a precise native speaker might well say that motorcycling is (or can be) dangerous.

Thanks, centrox.

Your reply confirms what I had always believed to be a phrase wrongly accepted by many people, including native speakers.

Inexactness or looseness is very common in relaxed or everyday speech and it would be a mistake to call it "wrong". In this case the focus is what leads one into danger. Sometimes it is important to be exact, for example one might fruitfully (not here! Please!) discuss the topic of whether guns or people kill people. To ride a motorcycle is to put oneself in more danger than when using other forms of transport, and to say therefore that "motorcycles are dangerous" is not really "wrong". You can imagine a teenager wanting to get a motorcycle being told that they are "dangerous" by their parents, and seeking to argue that it is the other road users who pose the danger. Whatever the fine language points, the fact remains that the teenager could suffer serious injury or death because of riding that motorcycle.

Thanks, centrox.

Noted.

Hi centrox, you had a motorcycle accident at age 22 that nearly killed you. I forgot to ask you what happened in the accident. Were you badly injured? It saddens me to hear that.

I was riding my motorcycle when a pedestrian tried to cross the road in front of me without looking, and I swerved to avoid her. I fell off and hit my face on the kerb. I was knocked unconscious, broke nine teeth and my nose in two places. I was, perhaps, exaggerating when I said I "nearly died". I could have put it better by saying "I could easily have been killed". I was in hospital for 2 weeks.

Thanks, centrox, for sharing your unpleasant experience.

In your case, I think I should say that pedestrians are dangerous.

Yes, you can say that inattentive pedestrians are dangerous, but it's likely that centrox would not have so badly injured if he'd been in a car. And he would not have been injured at all if he'd been a pedestrian himself.

Why not just leave "motorcycles are dangerous" as an acceptable thing to say, regardless of the specifics?

It's certain that I would not have injured physically at all, however the pedestrian would have been severely injured or killed. I agree that it is fine to say that "motorcycles are dangerous".