Having the drivetrain on the same side, as in the pic above, must be a standard on the majority of bikes, no?

Most bikes yes, but there are some left hand drive BMXs around, something to do with stunt pegs and keeping the drivetrain away from damage when using them on the ‘wrong’ side.

Wait, I’ve got it – the only standard is that a BIcycle has two [2] wheels.

That’s it.

Oh, and the bottle cage bolt spacing.

Probably.

Bloody hell!

Wait, I’ve got it – the only standard is that a BIcycle has two [2] wheels.

See my comment above – thread title says “cycling”.

The only standard I can think of is that people spend more time talking about it rather than doing it.

Actual water bottles? I know you can get wacky cages but if it’s a bike water bottle, it goes in a standard water bottle cage right?

Oh, and rust.

Northwind, you can get magnetic bottles to fit into the magnetic cages, don’t fit into normal cages as far as I am aware, but I may be wrong!

…and aero water bottles for TT handlebars

Handlebars are symmetrical, that’s quite standard. Unless its a special for disabled riders.

and the bottle cage bolt spacing