> The main reason why I have opted for old bicycles is that they are much better than new bicycles.<p>Uh no. New bicycles weigh less, are more aerodynamic, have safer disc brakes, and can have electric assist. The parts are engineered with better tolerances and use more appropriate dimensions for bottom brackets and handlebars. They use materials that don't rust or fatigue, like carbon fiber and titanium. Disc brakes alone are such a game-changer for bad weather riding that it's not worth owning a bike without them unless it's a novelty or antique. E-bikes are a big deal for getting people to switch to bikes for everyday trips.<p>> The most detailed life cycle analysis sets the carbon footprint for an 18.4 kg aluminum bicycle at 200 kg CO2, including its spare parts, for a lifetime of 15,000 km.<p>200 kg CO2 is equivalent to burning about 23 gallons of gas, something like 500 miles (800 km) for a typical car. My bike commute is 60 miles per week, so in terms of carbon my bike pays for itself every two months.<p>> Disc brakes, which are now on almost every new bicycle, all have different axle designs, meaning that every vehicle now requires proprietary spare parts.<p>I don't know what they're talking about regarding axle designs. The brake standard is independent of the axle design. It's true that different brake manufacturers have incompatible parts, but the parts being proprietary doesn't have anything to do with sustainability. They still cost the same to manufacture, and the spare parts are used eventually so it doesn't even matter if everyone has to keep some extras around.<p>> The rise of proprietary parts makes it increasingly hard to keep a bike on the road through maintenance, reuse, and refurbishment. As the number of incompatible components grows, it becomes impossible for bike shops to have a complete stock of spare parts.<p>Again, I don't know what they're on about. Bike shops carry the common manufacturers like Shimano and SRAM. Aside from Covid supply-chain problems I've always been able to get parts for all my bikes online.<p>To the extent that individual choices are effective for reducing carbon emissions, switching from a car trip to a bike trip is way more effective than switching from a less-sustainable bike trip to a more-sustainable bike trip. Advocating for bikes that are attractive to regular people is going to be much more effective than scraping meager wins in bike manufacturing.