We're doomed. A few thousand years on the planet and we still can't communicate. Here's one reason why.

The gears (well, we call them gears, they are actually sprockets) on the front of the bike are never referred to as gears but as "chainrings", though they might more accurately be described as disks. The gears on the back of the bike are called gears, not rings or disks and never sprokets. There are several of them and as a group they are referred to as a cassette. There may be a couple gears, err, chainrings up front too, but they are not called a cassette. No group of gears is called a "group set", that is something else (don't ask).

It's OK to call cogs "teeth" if they are on gears, sprockets or chainrings. But the ratio of cogs between gears is always a gear ratio, never a cog, tooth or even sprocket ratio.

Oh, and that wheel on the back with all the gears , err sprockets on it that must be set in motion by the gears, err chainrings up front is called the "free wheel". Though only if it is not a free hub. The wheel on the front of the bike that turns freely in either direction is not called the free wheel, the hub does not enter into it.

(Edit: I've been corrected. It's worse than I thought (:-/

Pardon my confusion, I'm just listening to Toad the Wet Chainring )