Engineers dont think abbout changing there product. you have to break the motor mount loose and jack the motor up to change the plugs in a 67 cougar,etc. and frame biulders consider them selves artists,also. they dont think about using a diff chainring or FD when they place the bottom water bottle gromet.

Not everybody wants to run a 52 or 42 toothed gear.

How to change pesky spark plugs:

I have a 63T chainring on my ICE Sprint 26" trike. I don't use it often, but why would a builder put on a braze-on for the 1%?

I had a '68 Dodge Dart GTS 340 and you had to jack it up and remove the driver's side front wheel to change the left side sparkplugs. And don't get me started on oil filter accessibility on so many cars. As you said, the designers don't have to work on what they design.

Sunbeam Tiger the Shoehorned in V8 required the back half of the motor was accessible, just from inside the car
under the dashboard.

Here is my thinking. The FD mounting/adjustment moves in 2 planes: vertical and rotational around the seat tube. Take the slotted braze-on adator for example, the slot provide the vertical adjustment. There is no reason why something like that can't be built in as part of the braze-on FD. Add another feature to allow limited rotational movement via screw(s) adjustment then all that is needed on a frame, no matter size or shape of the seattube, is just 2 holes.

The thing is I don't necessarily think that's an "improvement" but more of a progression just like many other features on the bike, especially with the carbon craze. The current design seems to work very well but it gotta be the most crude part of the bike.

Going along with this idea, bikes with odd, non-circular seattubes could indeed have two threaded holes, say rivnuts or similar installed on the seattube and the manufacturer's could provide two or more replicable bolt-on tabs with different dimensions to cover a range of large chainrings. The main problem with the current "braze-on" tabs is they are permanently brazed or riveted to the frame and, therefore, not sufficiently adjustable.

Geez, some of us don't run front derailleurs. No need to ruin a perfectly good frame with an unused FD tab or mount brazed on to it. I'm a IGH fan myself, sounds like something that might get in the way of my chain-guard.

A better question is; Why do cup & cone bearings still exist? bk

Do you want to turn this thread into a ten-page circle-jerk?!

To answer, serviceability, theoretically they handle the loads better, and they're cheaper while still doing the same job (they must be, or department-store BSOs would have cartridges not the cup-and-cone setups they do have).