4-man bicycle in intro scene

In the intro scene, during the festival/fundraising scene, I noticed something odd.

There's a four-person bicycle that rides by. I'm no expert in WWI era bicycles, but it felt out of place. The tires and hubs looked somehow wrong to me, too much like modern mountain bike tires. Freezing the frame, it looks like it has cast alloy crank arms, and most notably, some sort of large, formed plastic bit covering the rear wheel, with a center stand coming out the bottom. It also looks like a full rear cog cluster, which I don't think existed in those days. The suspicious front hub and most of the rear are covered by draped flags. The handlebars seem off, too, with the front one looking a lot like something from a 1970s Schwinn Stingray.

Anyway, it's a very minor issue. The men's haircuts are probably a way bigger issue. I'd write up a 'goofs' entry for it, but I don't know enough about the bicycles of each era to provide any good details.

Here's a screenshot: http://imgur.com/7vvJ8rS