Originally Posted by moleman76
That was the reason for "Swiss" threading in days of yore, with the lockring and left-side cup threaded left-handed, and the right-side cup right-handed, for bottom brackets, wasn't it?
Almost, but not quite the way that you described: flip around your threading and then you've got it.
English = Swiss for left/right threading (Good)
Italian = French for right/right threading (Not as good)
I'm not exactly sure of the geneology of the various different bicycle bottom bracket design standards, I just know that there are a lot of different variations and the pursuit of the "perfect" bottom bracket design continues today with the different variations of Octalink, ISIS, and now oversized ISIS, never mind other nuances such as the different ISO vs. JIS square taper standards.
The current "English" standard, aka B.S.A., B.S.C, Britsh, ISO was introduced back in the 20's by B.S.A. and it remains the most common, particulary in the US and, well, Britian. English BB's for road bikes are all 68mm wide and have a diameter of 1.370" with 24 threads per inch (TPI) and the right hand "fixing cup" is left-hand (reverse) threaded. This is the opposite of how pedals are threaded, but for the same reason: to ensure that precession works to tighten the component instead of loosening it.
Italian bottom brackets are all 70mm wide and have a diameter of 36mm with 24 threads per inch (TPI) and the right hand "fixing cup" is right-hand threaded. I don't know when or why the Italian standard was introduced but I'm sure someone could probably Google it and find out. The only thing nice about Italian threaded bottom brackets is that if you strip out your English-threaded BB you can have them re-tapped to the slightly larger Italian threading and use a 68mm BB cartridge made by a company that also offers its BBs in the Italian threading so that the cups are interchangeable. Other than that, Italian BBs just mean you need to pay attention to your bottom bracket after any maintenance to be sure that you've gotten it tightened enough to keep it from coming out as you ride.
French and Swiss both came into use in late 60's and disappeared in the 80's as they were pretty much failed standards (again, not at all uncommon with bottom bracket designs). They both use a width of 68mm and had a diameter of 35mm with 1.0mm threading. The difference was that the French used right-hand threading on both right and left bottom bracket cups (which meant they too would come unscrewed, just like the Italian standard) whereas the Swiss adopted the English/ISO approach of using a left-hand threaded fixing cup on the right side of the bike.
Pedal threading is the opposite of bottom bracket threading because the rotation of the axle relative to the crank and bottom bracket is reversed. Likewise, as you start heading into a pedal the direction of the threading and rotational forces flip-flops as well. If all the stars, moons, and threads are properly aligned, everything stays together. Once you start flipping things meant for right to left things can start to come undone.