I haven't cycled since I left the bike crazy place where I used to live before moving to Austin, and I never sought out the bicycle gear trinity in detail, but I always imagined anything more than three gears for commuter bikes is overkill - one for steep climbing, one for less steep climbing, one for flat land.

Most people in Davis used a single-speed with a free wheel or a fixed gear (ie if the wheels are spinning so are the pedals) which only have one gear. Then, if you were to get a bike with gears it'd have 8 or more speeds with front and rear derailieurs.

Trinities aren't sought in bike transmissions like I implied. I guess the trinity was mostly my thing and not a trend. For bike gears, it seems more common to believe more is more.