Originally Posted by rm -rf

A modest proposal:
Make 1/2 inch pitch chain obsolete.

The 12.7mm -- 1/2 inch pitch chain is way too big. It's heavy and limits the cog choices.

It's time to bring back the Shimano "10 pitch", 10mm chain. Or even smaller.

Make the chain narrower, too. Now you can fit 15 cogs.
In 1/2 inch equivalents, 11 12 13 14 15 16 17 18 19 20 22 25 28 32 36. Lots of close shifts and gears for steep hills.

Since we are redesigning everything, allow for more variation in the chainring sizes. Not fitting smaller than 34 chainrings was short sighted.

12.7mm vs 10 mm equivalent ratios (rounded to the nearest whole tooth):
10 tooth cog is the same as a 13 cog in 10mm.
20 tooth to 25
30 tooth to 38

34 chainring to 43.
50 chainring to 64

There's a limit to the diameter of the smallest cog that still fits on the cassette body. So the whole assembly can't just shrink down to 80% of the current sizes. Or can it?