I've worked on old and newer bikes. I ride a steel frame bike, that I built up from old parts.
It's hard to define the quality of a bike. Bikes are like an "ecosystem" that depends on dealers and at least modestly knowledgeable users, and a continuing supply of spare parts. It's not surprising that the longest-serving bikes are in countries with a strong cycling ecosystem.
A new bike made by a reputable brand like Trek is likely to be of very good quality, and benefits from some improvements in materials that have occurred since 1949, such as aluminum wheels and puncture resistant tires. If it receives light-duty service, such as commuting and shopping, and is proactively maintained, it can last forever.
The main threat to a decent bike is neglect. Also, "sportive" use of a bike, such as racing or off-road, brings its own list of issues, including obsolescence. The Dutch are deservedly famous for their bike culture, but their typical use is a few miles per day on well maintained roads and paths.
It's hard to define the quality of a bike. Bikes are like an "ecosystem" that depends on dealers and at least modestly knowledgeable users, and a continuing supply of spare parts. It's not surprising that the longest-serving bikes are in countries with a strong cycling ecosystem.
A new bike made by a reputable brand like Trek is likely to be of very good quality, and benefits from some improvements in materials that have occurred since 1949, such as aluminum wheels and puncture resistant tires. If it receives light-duty service, such as commuting and shopping, and is proactively maintained, it can last forever.
The main threat to a decent bike is neglect. Also, "sportive" use of a bike, such as racing or off-road, brings its own list of issues, including obsolescence. The Dutch are deservedly famous for their bike culture, but their typical use is a few miles per day on well maintained roads and paths.