Functional bikes. Not Porn not Anti

and difficult idea to put a "cheap" bb on a 8k€ bike... !

Well, if you think about it, a lots of components on expensive bike are cheap, such as the brake cable, chains, cassette, even the stem.

You don't need to spend a lots of money on cassette, they all wear out almost equally, nor a chain for similar reason.

Brake cable can be hard to tell, the biggest difference is usually housing and the cable housing end (cheap housing end actually create friction).

Stem, you can just get a £15 one that work just as well as a £80 one, the difference is way too small to warrant such upgrade (maybe lose 5 to 10g, perhaps a little stiffer), and even those difference may be hard to notice to some people.

There are some components that are worth spending money on, but a lots of them that are not necessary.