The amount of damage to tires is proportional to the fourth power of the weight per axel. That means that for the same journey, a bike sheds (3000 kg / 80 kg)ˆ4 so about 20 million times less. Assuming that the rubber is the same—and not that it has proprietary chemistry that may or may not contain carcinogens. Eight orders of magnitude of difference feels relevant.

Almost every train I know use metal wheels. We can look at the few that don’t, but something tells me people who raise that argument don’t want to look at alternative wheel composition, but rather hope to seed doubt and, in private, lobby replace one metro with thousands of cars, and I’m not sure that’s a good idea.

So, please, don’t come in here with that bullshit.