AFAIK the car makers are required to maintain inventories of spares. And whether by this mechanism or some other, cars have fairly accurate and consistent parts lists, making it relatively easy to figure out which part number is needed for which car. Perhaps the higher volume of car repairs also supports a competitive market for providing parts on quick notice. My independent mechanic has never taken more than a day to fix my car, and that includes getting the parts.

With bikes, it's a crap shoot. A typical new bike model does not come with a parts list, and the brands don't stock spares. Every repair turns into a guessing game on which part will actually fit the bike, and a search for a supplier. If the shop needs a part, it has to be ordered and shipped from some distant city. The parts makers (e.g., the biggest one is Shimano) decide when a particular style of part is obsolete and discontinued, and you're on your own.

Cheaper bikes (within reason) are better -- they tend to use parts from older standards that are still in widespread use worldwide. For instance there was a long time period (after the so called "bike boom") when most bikes had reasonably interchangeable parts, and many of those component standards such as bottom brackets are still being used today. My hacked together bikes from 1980s parts are still easy to maintain today with minimal skills and tools.

The other thing is, the vast majority of cars are not used for competition or sport, and are treated to fairly mild and predictable operating conditions, the exception being when they crash.

> A typical new bike model does not come with a parts list, and the brands don't stock spares.

This is probably true for BSOs, but you start getting a complete list of components on a bicycle well before you hit the $1000 price point, and generally everything other than the brake pads are extremely standardized and easy to find. For whatever reason manufacturers really like to get creative with disk brake pad shapes.

I've hacked on bikes since the 80's, and I think things are better now(ish), at least if you're not going full squish or hydraulic brakes.

I've got 2 bikes with SRAM Rival and Apex that have had perfectly crisp shifting for 7k miles each. There might have been one adjustment barrel turn in there somewhere. They've got some sort of modern, trouble free bottom bracket with a hollow axle. I don't even know, because it's that maintenance free. And that shifting? Much easier than the post bike boom downtube friction shifters.

Whereas with my 80's tech bikes, I repacked hubs and bottom brackets every so often, at least until I went with the (more disposable) shimano cartridge BBs. Shifting always needed a little bit of adjustment. My wheels were better than, but I built those wheels (and I know my stuff), but I'm using commercial wheels now. Changing brake pads now is a 2 minute job, just slide them out and put new ones in. It used to be that you'd need to re-align the brake shoes too.

Maybe I wasn't all that good at it, but I think I was decent at wrenching. I can strip and reassemble a bike, with the possible exception of the headset races. The bikes now might be less maintainable, but critically, my bikes now just don't need as much maintenance.

The invention of the 4 bolt face for the stem is 1000% better than quill stems where you had to pull the brakes and tape off to get 10mm more or less reach. They're also significantly less likely for them to move around against the fork. Threadless headsets are also far easier to set properly and keep them there.

The style of larger tires on road bikes is awesome. Comfort and speed. It's nice to be able to get a sub 15 lb bike. 18 used to be stupid light, now it's just a bit pricey. They're not workhorses, but they're fun.

For utility, racks are better now. Low rider front racks and the standard mount rear racks were only really introduced in the 80s. There are good front and rear racks at multiple price points that work for light duty or full blown continent crossing epics. You can _get_ cargo bikes, in a variety of shapes, with e-boost and not.

Yes, there are bits that aren't compatible. Most shifters need to be paired with compatible derailleurs. Be careful on hydraulic brakes. You have to know if you have disks or rim brakes. You might need to use the proper chain, at least of the right # of speeds. It's difficult to find 27" rim/tires anymore. Shimano doesn't sell replacement bearing cups for their hubs, though you can get the cones. Campy does tho. Its really hard to find a good 8sp mountain freewheel these days.

If you want, you can still go full analog and get downtube 11sp friction shifters with non-aero center pull brakes, all with new parts, and it's not even that hard to find if you know where to look, though economy of scale means that it's not going to be cheap.

So, The glass is far more than half full.

It's not really. Any decent bike shop has bins full of spare parts and take-offs. Then you always have eBay, Marketplace, etc. to find something strange.

The most common consumer bikes aren't meant to ridden aggressively. Even those suffer from perpetual incompatibility due to trends.

Compare that to something like Toyota Carolla or Honda Civic. Parts are often interchangeable across model years. There's a huge stock in junk yards.

A decent off road bicycle is niche in comparison. Every 2-3 years some new standard is introduced.

I wouldn't trust my safety on a used bottom bracket or crank arm. Who knows what kinds of insanity the previous owner was involved in?

Because cars are expensive, large, and there are only a very few models (relatively) that share tons of parts.

Bikes are smaller and cheaper and the parts are not as interchangeable unless you can weld (and if you have cheap bikes you just buy new).

Bicycle parts are incredibly standardized compared to cars. Outside exotic racing bikes almost every brand uses the same Shimano parts or compatible copies from other brands. And even between component brands, the way the components attach to frames are somewhat standardized so replacing an entire Shimano drivetrain with Campagnolo or vice versa is possible. The problem is that there are a bit too many standards now.

Those are the "good bikes" - the article (and I suspect the vast majority of bikes) are the Walmart specials, some of which might use standard components but much of which appear to be one-offs or similar.

It would be nice if there WAS a standard - some rating on the box indicating how "replaceable" parts on the bike are, somehow.

I'm not from the US so I can't just go to Walmart and see. What are these non-standard parts? I'm aware that cheap shock absorbers can be quite wild but what weird parts would a non-suspension bike have? Of course you don't have threaded headsets or freewheels on nice bikes but those are still available and don't have many variants.

The cheapest bikes have weird size pedal assemblies that don’t take “normal” ones and such - but the real problem is a cheap Walmart bike is $98.

A single derailleur can cost more than that! No wonder people just throw them away.

I agree that the main reason these things aren't repaired is that a new bike costs less than a couple of spare parts and labor.

But I seriously doubt that the weird size pedal assembly is something else than bog standard Fauber crank. Those things are still made and I can't imagine how a custom part would be cheaper to manufacture.

All of that exists, it's just .. mostly stolen.

(This is probably location dependent, I have no doubt that the Netherlands supports a density of bike shops adequate to its millions of daily bike users)