Left-side drive

Matthew Acton-Varian wrote:

Because of production costs conventional gearing and commercially available products tend to revert to the default right hand side. The idea being you avoid giving your trousers the Victorian equivalent of a Cat 4 Tat when you step off as the bike leans on to your standing leg on the pavement.

Given that nearly all of Europe, China, Russia and the Americas drive on the right, so their standing leg when dismounting would usually be the right, surely the market would default to a left-side drive train if that were the reason?

The safety bicycle was a British invention, and the idea of the drivetrain being on the right had become standard long before motor vehicles really became a thing. The idea of specific travelling lanes wasn't officially established until much later. It was common in the days of horse and cart for people to just ride any way they saw fit.

I was wondering about the ratchet going the wrong way, but if it's quite common in BMX there must be enough of a market. Bit of DIY needed for the first one, or is it a "fairly simple" modification?

As it is a single speed freewheel sprocket, and the inner surface is threaded throughout, you can just flip the freewheel assembly over and attach it in reverse, providing you have the tool interface on both sides. I don't know if they use reverse thread lockrings like track sprockets to keep it secure, though.