Originally Posted by
gmt13
Still looking into this. The threading theory is looking like a myth. Apparently, up until the 1890's drives were on either side, but they became standardised to the right side during the turn of the century boom. Nevertheless, Archibald Sharpe in his 1896 treatise describes cogs as often being soldered onto the hub, which makes the thread argument moot. He describes the Elswick hub, which has the cog on the left, as having a thread pattern that causes the cog to tighten when pedaled and then goes on to say, that if you have the drive side on the right, then the threads should be right hand.
The Abingdon hubs of the early 90s made hubs that had a 10 sided polygonal surface that matched the cog, which was then soldered on.
I am going to bet that the right-side/left-side issue was settled as a fashion whim, much like folks want hub stickers to be aligned with sides and hub stampings these days.
Have a better argument?
Here's a pic of an 1893 repro.

I don't have a better arguement, but I'm staying with my arguement until proof can be shown that that wasn't the case at all. Please let us know what you dig up, it would be interesting.